Merge pull request #3 from HarnessLab/dev

Add new agent core components

PARITY_CHECKLIST.md

@@ -26,6 +26,7 @@ Done:
 - [x] Incremental tool-result streaming for read-only text tools
 - [x] Mutable tool transcript updates during tool execution
 - [x] Transcript mutation history for replaced/tombstoned messages
+- [x] Assistant streaming and tool-call transcript mutation history
 - [x] Structured transcript block export for messages, tool calls, and tool results
 - [x] Resume-time file-history replay reminders
 - [x] Resume-time file-history snapshot previews for file edits
@@ -39,26 +40,42 @@ Done:
 - [x] Sequential multi-subtask delegation with parent-context carryover
 - [x] Basic agent-manager lineage tracking for nested agents
 - [x] Managed agent-group membership tracking with child indices
+- [x] Delegated child-session resume by saved session id
+- [x] Agent-manager tracking for resumed child-session lineage
 - [x] Plugin-cache discovery and prompt-context injection
 - [x] Manifest-based plugin runtime discovery
 - [x] Manifest-defined plugin hooks for before-prompt and after-turn runtime injection
 - [x] Manifest-defined plugin tool aliases over base runtime tools
+- [x] Manifest-defined executable virtual tools
 - [x] Manifest-defined plugin tool blocking
+- [x] Manifest-defined plugin `beforeTool` guidance
 - [x] Manifest-defined plugin tool-result guidance injected back into the transcript
 - [x] Compaction metadata with compacted message ids
+- [x] Compaction metadata with preserved-tail ids and compaction depth
+- [x] Compaction metadata with compacted/preserved lineage ids and revision summaries
+- [x] Snipped-message metadata with source role/kind lineage
+- [x] Snipped-message metadata with source lineage id and revision
 - [x] Resume-time compaction / snipping replay reminder
 - [x] Query-engine facade that can drive the real Python runtime agent
 - [x] Query-engine runtime event counters and transcript-kind summaries
+- [x] Query-engine runtime mutation counters
+- [x] Query-engine stream-level runtime summary event
+- [x] Query-engine transcript-store compaction summaries
+- [x] Delegate-group and delegated-subtask runtime events
+- [x] Query-engine runtime orchestration summaries for group status and child stop reasons
+- [x] Query-engine runtime context-reduction summaries
+- [x] Query-engine runtime lineage summaries
+- [x] Query-engine runtime resumed-child orchestration summaries
 
 Missing:
 
 - [ ] Full partial tool-result streaming parity across the complete tool surface
 - [ ] Full rich transcript mutation behavior like the npm runtime
 - [ ] Full reasoning budgets and task budgets parity
-- [ ] Full multi-agent orchestration parity
+- [ ] Full multi-agent orchestration parity beyond sequential grouped delegation and resumed-child flows
 - [ ] Full file history snapshots and replay flows
-- [ ] Full executable plugin lifecycle beyond runtime guidance, blocking, and aliases
+- [ ] Full executable plugin lifecycle beyond manifest-driven guidance, blocking, aliases, and virtual tools
-- [ ] Full session compaction / snipping parity
+- [ ] Full session compaction / snipping parity beyond lineage-aware summaries and replay reminders
 - [ ] Full `QueryEngine.ts` parity
 
 ## 2. CLI Entrypoints And Runtime Modes

src/agent_manager.py

@@ -11,6 +11,7 @@ class ManagedAgentRecord:
     group_id: str | None = None
     child_index: int | None = None
     label: str | None = None
+    resumed_from_session_id: str | None = None
     session_id: str | None = None
     session_path: str | None = None
     status: str = 'running'
@@ -45,6 +46,7 @@ class AgentManager:
         group_id: str | None = None,
         child_index: int | None = None,
         label: str | None = None,
+        resumed_from_session_id: str | None = None,
     ) -> str:
         self._counter += 1
         agent_id = f'agent_{self._counter}'
@@ -55,6 +57,7 @@ class AgentManager:
             group_id=group_id,
             child_index=child_index,
             label=label,
+            resumed_from_session_id=resumed_from_session_id,
         )
         if group_id is not None:
             self.register_group_child(group_id, agent_id, child_index=child_index)
@@ -110,6 +113,7 @@ class AgentManager:
             group_id=group_id,
             child_index=child_index,
             label=record.label,
+            resumed_from_session_id=record.resumed_from_session_id,
             session_id=record.session_id,
             session_path=record.session_path,
             status=record.status,
@@ -159,6 +163,7 @@ class AgentManager:
             group_id=record.group_id,
             child_index=record.child_index,
             label=record.label,
+            resumed_from_session_id=record.resumed_from_session_id,
             session_id=session_id,
             session_path=session_path,
             status='completed',
@@ -174,6 +179,44 @@ class AgentManager:
             if record.parent_agent_id == agent_id
         )
 
+    def group_children(self, group_id: str) -> tuple[ManagedAgentRecord, ...]:
+        return tuple(
+            sorted(
+                (
+                    record for record in self.records.values()
+                    if record.group_id == group_id
+                ),
+                key=lambda record: (
+                    record.child_index is None,
+                    record.child_index or 0,
+                    record.agent_id,
+                ),
+            )
+        )
+
+    def group_summary(self, group_id: str) -> dict[str, object] | None:
+        group = self.groups.get(group_id)
+        if group is None:
+            return None
+        children = self.group_children(group_id)
+        stop_reason_counts: dict[str, int] = {}
+        resumed_children = 0
+        for child in children:
+            if child.resumed_from_session_id:
+                resumed_children += 1
+            stop_reason = child.stop_reason or 'n/a'
+            stop_reason_counts[stop_reason] = stop_reason_counts.get(stop_reason, 0) + 1
+        return {
+            'group_id': group.group_id,
+            'label': group.label,
+            'status': group.status,
+            'child_count': len(children),
+            'completed_children': group.completed_children,
+            'failed_children': group.failed_children,
+            'resumed_children': resumed_children,
+            'stop_reason_counts': stop_reason_counts,
+        }
+
     def completed_records(self) -> tuple[ManagedAgentRecord, ...]:
         return tuple(
             record for record in self.records.values() if record.status == 'completed'
@@ -186,6 +229,10 @@ class AgentManager:
         ]
         child_count = sum(1 for record in self.records.values() if record.parent_agent_id)
         lines.append(f'- Child agents: {child_count}')
+        resumed_count = sum(
+            1 for record in self.records.values() if record.resumed_from_session_id
+        )
+        lines.append(f'- Resumed agents: {resumed_count}')
         lines.append(f'- Agent groups: {len(self.groups)}')
         completed_groups = sum(1 for group in self.groups.values() if group.status == 'completed')
         lines.append(f'- Completed groups: {completed_groups}')
@@ -196,6 +243,8 @@ class AgentManager:
                 group_bits.append(f'group={record.group_id}')
             if record.child_index is not None:
                 group_bits.append(f'child_index={record.child_index}')
+            if record.resumed_from_session_id is not None:
+                group_bits.append(f'resumed_from={record.resumed_from_session_id}')
             group_suffix = f" {' '.join(group_bits)}" if group_bits else ''
             lines.append(
                 f'- {label}: status={record.status} turns={record.turns} '
@@ -205,9 +254,19 @@ class AgentManager:
             lines.append(f'- ... plus {len(self.records) - 8} more managed agents')
         for group in sorted(self.groups.values(), key=lambda item: item.group_id)[:6]:
             label = group.label or group.group_id
+            summary = self.group_summary(group.group_id)
+            if summary is None:
+                continue
+            stop_bits = summary['stop_reason_counts']
+            stop_suffix = ''
+            if isinstance(stop_bits, dict) and stop_bits:
+                stop_suffix = ' stop_reasons=' + ','.join(
+                    f'{name}:{count}' for name, count in sorted(stop_bits.items())
+                )
             lines.append(
                 f'- {label}: group_status={group.status} children={len(group.child_agent_ids)} '
                 f'completed={group.completed_children} failed={group.failed_children} '
+                f"resumed={summary['resumed_children']}{stop_suffix}"
             )
         if len(self.groups) > 6:
             lines.append(f'- ... plus {len(self.groups) - 6} more agent groups')

src/agent_runtime.py

@@ -4,6 +4,7 @@ from dataclasses import dataclass, field, replace
 from datetime import datetime, timezone
 import json
 from pathlib import Path
+from typing import Any
 from uuid import uuid4
 
 from .agent_manager import AgentManager
@@ -40,6 +41,7 @@ from .openai_compat import OpenAICompatClient, OpenAICompatError
 from .plugin_runtime import PluginRuntime
 from .session_store import (
     StoredAgentSession,
+    load_agent_session,
     save_agent_session,
     serialize_model_config,
     serialize_runtime_config,
@@ -64,12 +66,14 @@ class LocalCodingAgent:
     parent_agent_id: str | None = None
     managed_group_id: str | None = None
     managed_child_index: int | None = None
+    managed_label: str | None = None
     plugin_runtime: PluginRuntime | None = None
     last_session: AgentSessionState | None = field(default=None, init=False, repr=False)
     last_run_result: AgentRunResult | None = field(default=None, init=False, repr=False)
     active_session_id: str | None = field(default=None, init=False, repr=False)
     last_session_path: str | None = field(default=None, init=False, repr=False)
     managed_agent_id: str | None = field(default=None, init=False, repr=False)
+    resume_source_session_id: str | None = field(default=None, init=False, repr=False)
 
     def __post_init__(self) -> None:
         if self.tool_registry is None:
@@ -81,9 +85,14 @@ class LocalCodingAgent:
                 self.runtime_config.cwd,
                 tuple(str(path) for path in self.runtime_config.additional_working_directories),
             )
-        plugin_tools = self.plugin_runtime.register_tool_aliases(self.tool_registry)
+        registry = dict(self.tool_registry)
+        plugin_tools = self.plugin_runtime.register_tool_aliases(registry)
         if plugin_tools:
-            self.tool_registry = {**self.tool_registry, **plugin_tools}
+            registry = {**registry, **plugin_tools}
+        virtual_tools = self.plugin_runtime.register_virtual_tools(registry)
+        if virtual_tools:
+            registry = {**registry, **virtual_tools}
+        self.tool_registry = registry
         self.client = OpenAICompatClient(self.model_config)
         self.tool_context = build_tool_context(self.runtime_config)
 
@@ -96,6 +105,7 @@ class LocalCodingAgent:
         self.last_run_result = None
         self.active_session_id = None
         self.last_session_path = None
+        self.resume_source_session_id = None
 
     def build_prompt_context(self, scratchpad_directory: Path | None = None):
         return build_prompt_context(
@@ -133,6 +143,7 @@ class LocalCodingAgent:
 
     def run(self, prompt: str) -> AgentRunResult:
         self.managed_agent_id = None
+        self.resume_source_session_id = None
         session_id = uuid4().hex
         scratchpad_directory = self._ensure_scratchpad_directory(session_id)
         result = self._run_prompt(
@@ -147,6 +158,7 @@ class LocalCodingAgent:
 
     def resume(self, prompt: str, stored_session: StoredAgentSession) -> AgentRunResult:
         self.managed_agent_id = None
+        self.resume_source_session_id = stored_session.session_id
         session = AgentSessionState.from_persisted(
             system_prompt_parts=stored_session.system_prompt_parts,
             user_context=stored_session.user_context,
@@ -207,7 +219,8 @@ class LocalCodingAgent:
             parent_agent_id=self.parent_agent_id,
             group_id=self.managed_group_id,
             child_index=self.managed_child_index,
-            label='root' if base_session is None else 'resume',
+            label=self.managed_label or ('root' if base_session is None else 'resume'),
+            resumed_from_session_id=self.resume_source_session_id,
         )
         session = (
             base_session
@@ -521,6 +534,17 @@ class LocalCodingAgent:
                         'message_id': session.messages[tool_message_index].message_id,
                     }
                 )
+                plugin_preflight_messages = self._plugin_tool_preflight_messages(tool_call.name)
+                if plugin_preflight_messages:
+                    stream_events.append(
+                        {
+                            'type': 'plugin_tool_preflight',
+                            'tool_name': tool_call.name,
+                            'tool_call_id': tool_call.id,
+                            'message_id': session.messages[tool_message_index].message_id,
+                            'message_count': len(plugin_preflight_messages),
+                        }
+                    )
                 plugin_block_message = self._plugin_block_message(tool_call.name)
                 if plugin_block_message is not None:
                     tool_result = ToolExecutionResult(
@@ -592,38 +616,12 @@ class LocalCodingAgent:
                                 'message': message,
                             }
                         )
-                plugin_runtime_message = self._build_plugin_tool_runtime_message(
-                    tool_name=tool_call.name,
-                    block_message=plugin_block_message,
-                    plugin_messages=plugin_messages,
-                )
-                if plugin_runtime_message is not None:
-                    session.append_user(
-                        plugin_runtime_message,
-                        metadata={
-                            'kind': 'plugin_tool_runtime',
-                            'tool_name': tool_call.name,
-                            'tool_call_id': tool_call.id,
-                            'plugin_blocked': plugin_block_message is not None,
-                            'plugin_message_count': len(plugin_messages),
-                        },
-                        message_id=f'plugin_tool_runtime_{tool_call.id}',
-                    )
-                    stream_events.append(
-                        {
-                            'type': 'plugin_tool_context',
-                            'tool_name': tool_call.name,
-                            'tool_call_id': tool_call.id,
-                            'message_id': f'plugin_tool_runtime_{tool_call.id}',
-                            'blocked': plugin_block_message is not None,
-                            'message_count': len(plugin_messages),
-                        }
-                    )
                 session.finalize_tool(
                     tool_message_index,
                     content=serialize_tool_result(tool_result),
                     metadata={
                         'phase': 'completed',
+                        'plugin_preflight_messages': list(plugin_preflight_messages),
                         **dict(tool_result.metadata),
                     },
                     stop_reason='tool_completed',
@@ -638,6 +636,41 @@ class LocalCodingAgent:
                         'metadata': dict(tool_result.metadata),
                     }
                 )
+                self._append_runtime_tool_followup_events(
+                    stream_events,
+                    tool_call=tool_call,
+                    tool_result=tool_result,
+                )
+                plugin_runtime_message = self._build_plugin_tool_runtime_message(
+                    tool_name=tool_call.name,
+                    preflight_messages=plugin_preflight_messages,
+                    block_message=plugin_block_message,
+                    plugin_messages=plugin_messages,
+                )
+                if plugin_runtime_message is not None:
+                    session.append_user(
+                        plugin_runtime_message,
+                        metadata={
+                            'kind': 'plugin_tool_runtime',
+                            'tool_name': tool_call.name,
+                            'tool_call_id': tool_call.id,
+                            'plugin_blocked': plugin_block_message is not None,
+                            'plugin_message_count': len(plugin_messages),
+                            'plugin_preflight_count': len(plugin_preflight_messages),
+                        },
+                        message_id=f'plugin_tool_runtime_{tool_call.id}',
+                    )
+                    stream_events.append(
+                        {
+                            'type': 'plugin_tool_context',
+                            'tool_name': tool_call.name,
+                            'tool_call_id': tool_call.id,
+                            'message_id': f'plugin_tool_runtime_{tool_call.id}',
+                            'blocked': plugin_block_message is not None,
+                            'message_count': len(plugin_messages),
+                            'preflight_count': len(plugin_preflight_messages),
+                        }
+                    )
                 history_entry = self._build_file_history_entry(
                     tool_call=tool_call,
                     tool_result=tool_result,
@@ -980,6 +1013,11 @@ class LocalCodingAgent:
                     'original_token_estimate': original_tokens,
                     'replacement_token_estimate': replacement_tokens,
                     'snipped_turn_index': turn_index,
+                    'snipped_from_role': message.role,
+                    'snipped_from_message_id': message.message_id,
+                    'snipped_from_kind': message.metadata.get('kind'),
+                    'snipped_from_lineage_id': message.metadata.get('lineage_id'),
+                    'snipped_from_revision': message.metadata.get('revision'),
                 },
             )
             delta = original_tokens - replacement_tokens
@@ -1024,6 +1062,7 @@ class LocalCodingAgent:
         if compact_end <= prefix_count:
             return False
         candidates = session.messages[prefix_count:compact_end]
+        preserved_tail = list(session.messages[compact_end:])
         if not candidates:
             return False
         compacted_tokens = sum(
@@ -1048,6 +1087,7 @@ class LocalCodingAgent:
             estimated_tokens_before=usage_total,
             estimated_tokens_removed=compacted_tokens,
             preserved_tail_count=tail_count,
+            preserved_tail=preserved_tail,
         )
         session.messages = (
             session.messages[:prefix_count]
@@ -1062,6 +1102,11 @@ class LocalCodingAgent:
                 'estimated_tokens_before': usage_total,
                 'estimated_tokens_removed': compacted_tokens,
                 'preserved_tail_count': tail_count,
+                'preserved_tail_ids': [
+                    message.message_id for message in preserved_tail if message.message_id
+                ],
+                'compaction_depth': compact_message.metadata.get('compaction_depth'),
+                'nested_compaction_count': compact_message.metadata.get('nested_compaction_count'),
                 'compacted_message_ids': [
                     message.message_id for message in candidates if message.message_id
                 ],
@@ -1183,6 +1228,7 @@ class LocalCodingAgent:
         estimated_tokens_before: int,
         estimated_tokens_removed: int,
         preserved_tail_count: int,
+        preserved_tail,
     ):
         summary_lines = [
             '<system-reminder>',
@@ -1215,17 +1261,65 @@ class LocalCodingAgent:
         )
         from .agent_session import AgentMessage
 
+        nested_compaction_count = sum(
+            1 for message in messages if message.metadata.get('kind') == 'compact_boundary'
+        )
+        prior_depths = [
+            int(message.metadata.get('compaction_depth', 0))
+            for message in messages
+            if isinstance(message.metadata.get('compaction_depth', 0), int)
+        ]
+        compaction_depth = (max(prior_depths) if prior_depths else 0) + 1
+        compacted_kinds: dict[str, int] = {}
+        compacted_lineage_ids: list[str] = []
+        preserved_tail_lineage_ids = [
+            lineage_id
+            for lineage_id in (
+                message.metadata.get('lineage_id') for message in preserved_tail
+            )
+            if isinstance(lineage_id, str) and lineage_id
+        ]
+        max_source_revision = 0
+        compacted_revision_total = 0
+        for message in messages:
+            kind = message.metadata.get('kind')
+            label = str(kind) if isinstance(kind, str) and kind else message.role
+            compacted_kinds[label] = compacted_kinds.get(label, 0) + 1
+            lineage_id = message.metadata.get('lineage_id')
+            if isinstance(lineage_id, str) and lineage_id:
+                compacted_lineage_ids.append(lineage_id)
+            revision = message.metadata.get('revision')
+            if isinstance(revision, int) and not isinstance(revision, bool):
+                max_source_revision = max(max_source_revision, revision)
+                compacted_revision_total += revision
+
+        compact_boundary_id = f'compact_boundary_{turn_index}_{len(messages)}'
+
         return AgentMessage(
             role='system',
             content='\n'.join(summary_lines),
-            message_id=f'compact_boundary_{turn_index}_{len(messages)}',
+            message_id=compact_boundary_id,
             metadata={
                 'kind': 'compact_boundary',
+                'lineage_id': compact_boundary_id,
+                'revision': 0,
+                'revision_count': 1,
+                'message_role': 'system',
                 'turn_index': turn_index,
                 'compacted_message_count': len(messages),
                 'estimated_tokens_before': estimated_tokens_before,
                 'estimated_tokens_removed': estimated_tokens_removed,
                 'preserved_tail_count': preserved_tail_count,
+                'preserved_tail_ids': [
+                    message.message_id for message in preserved_tail if message.message_id
+                ],
+                'compaction_depth': compaction_depth,
+                'nested_compaction_count': nested_compaction_count,
+                'compacted_kinds': compacted_kinds,
+                'compacted_lineage_ids': compacted_lineage_ids,
+                'preserved_tail_lineage_ids': preserved_tail_lineage_ids,
+                'max_source_revision': max_source_revision,
+                'compacted_revision_total': compacted_revision_total,
                 'compacted_message_ids': [
                     message.message_id for message in messages if message.message_id
                 ],
@@ -1298,6 +1392,7 @@ class LocalCodingAgent:
         failed_children = 0
         child_result = None
         for index, subtask in enumerate(subtasks, start=1):
+            subtask_label = str(subtask.get('label') or f'subtask_{index}')
             child_agent = LocalCodingAgent(
                 model_config=self.model_config,
                 runtime_config=replace(
@@ -1312,6 +1407,7 @@ class LocalCodingAgent:
                 parent_agent_id=self.managed_agent_id,
                 managed_group_id=group_id,
                 managed_child_index=index,
+                managed_label=subtask_label,
             )
             if group_id is not None and child_agent.managed_agent_id is not None:
                 self.agent_manager.register_group_child(
@@ -1322,6 +1418,48 @@ class LocalCodingAgent:
             child_prompt = str(subtask['prompt'])
             if include_parent_context and prior_results:
                 child_prompt = self._prepend_delegate_context(child_prompt, prior_results)
+            resume_session_id = subtask.get('resume_session_id')
+            resume_used = False
+            if isinstance(resume_session_id, str) and resume_session_id:
+                try:
+                    stored_child_session = load_agent_session(
+                        resume_session_id,
+                        directory=child_runtime_config.session_directory,
+                    )
+                except OSError:
+                    child_result = AgentRunResult(
+                        final_output=f'Unable to load delegated session {resume_session_id}.',
+                        turns=0,
+                        tool_calls=0,
+                        transcript=(),
+                        stop_reason='resume_load_error',
+                        session_id=resume_session_id,
+                    )
+                    failed_children += 1
+                    summary = {
+                        'index': index,
+                        'label': subtask_label,
+                        'session_id': resume_session_id,
+                        'turns': child_result.turns,
+                        'tool_calls': child_result.tool_calls,
+                        'stop_reason': child_result.stop_reason or 'resume_load_error',
+                        'output_preview': self._preview_text(child_result.final_output, 220),
+                        'resume_used': True,
+                        'resumed_from_session_id': resume_session_id,
+                    }
+                    child_summaries.append(summary)
+                    prior_results.append(
+                        {
+                            'label': summary['label'],
+                            'output_preview': str(summary['output_preview']),
+                        }
+                    )
+                    if not continue_on_error:
+                        break
+                    continue
+                child_result = child_agent.resume(child_prompt, stored_child_session)
+                resume_used = True
+            else:
                 child_result = child_agent.run(child_prompt)
             if group_id is not None and child_agent.managed_agent_id is not None:
                 self.agent_manager.register_group_child(
@@ -1331,12 +1469,18 @@ class LocalCodingAgent:
                 )
             summary = {
                 'index': index,
-                'label': str(subtask.get('label') or f'subtask_{index}'),
+                'label': subtask_label,
                 'session_id': child_result.session_id or '',
                 'turns': child_result.turns,
                 'tool_calls': child_result.tool_calls,
                 'stop_reason': child_result.stop_reason or 'stop',
                 'output_preview': self._preview_text(child_result.final_output, 220),
+                'resume_used': resume_used,
+                'resumed_from_session_id': (
+                    str(resume_session_id)
+                    if isinstance(resume_session_id, str) and resume_session_id
+                    else ''
+                ),
             }
             child_summaries.append(summary)
             if child_result.session_id:
@@ -1353,6 +1497,9 @@ class LocalCodingAgent:
                     break
         assert child_result is not None
         completed_children = len(child_summaries) - failed_children
+        resumed_children = sum(
+            1 for summary in child_summaries if summary.get('resume_used')
+        )
         group_status = 'completed'
         if failed_children and completed_children:
             group_status = 'partial'
@@ -1375,6 +1522,7 @@ class LocalCodingAgent:
         if group_id is not None:
             summary_lines.append(f'group_id={group_id}')
             summary_lines.append(f'group_status={group_status}')
+            summary_lines.append(f'resumed_children={resumed_children}')
             summary_lines.append('')
         for summary in child_summaries:
             summary_lines.extend(
@@ -1384,6 +1532,8 @@ class LocalCodingAgent:
                     f"turns={summary['turns']}",
                     f"tool_calls={summary['tool_calls']}",
                     f"stop_reason={summary['stop_reason']}",
+                    f"resume_used={summary['resume_used']}",
+                    f"resumed_from_session_id={summary['resumed_from_session_id']}",
                     f"output_preview={summary['output_preview']}",
                     '',
                 ]
@@ -1407,6 +1557,7 @@ class LocalCodingAgent:
                 'group_status': group_status,
                 'failed_children': failed_children,
                 'completed_children': completed_children,
+                'resumed_children': resumed_children,
             },
         )
 
@@ -1431,13 +1582,24 @@ class LocalCodingAgent:
                         'prompt': prompt.strip(),
                         'label': label if isinstance(label, str) and label.strip() else f'subtask_{index}',
                     }
+                    resume_session_id = item.get('resume_session_id')
+                    if resume_session_id is None:
+                        resume_session_id = item.get('session_id')
+                    if isinstance(resume_session_id, str) and resume_session_id.strip():
+                        task['resume_session_id'] = resume_session_id.strip()
                     if isinstance(max_turns, int) and not isinstance(max_turns, bool) and max_turns > 0:
                         task['max_turns'] = max_turns
                     subtasks.append(task)
         prompt = arguments.get('prompt')
         if isinstance(prompt, str) and prompt.strip():
             if not subtasks:
-                subtasks.append({'prompt': prompt.strip(), 'label': 'subtask_1'})
+                task: dict[str, object] = {'prompt': prompt.strip(), 'label': 'subtask_1'}
+                resume_session_id = arguments.get('resume_session_id')
+                if resume_session_id is None:
+                    resume_session_id = arguments.get('session_id')
+                if isinstance(resume_session_id, str) and resume_session_id.strip():
+                    task['resume_session_id'] = resume_session_id.strip()
+                subtasks.append(task)
         return subtasks[:8]
 
     def _delegated_task_units(
@@ -1476,6 +1638,60 @@ class LocalCodingAgent:
         lines.extend(['</system-reminder>', '', prompt])
         return '\n'.join(lines)
 
+    def _append_runtime_tool_followup_events(
+        self,
+        stream_events: list[dict[str, object]],
+        *,
+        tool_call: ToolCall,
+        tool_result: ToolExecutionResult,
+    ) -> None:
+        metadata = tool_result.metadata
+        if metadata.get('action') == 'plugin_virtual_tool':
+            stream_events.append(
+                {
+                    'type': 'plugin_virtual_tool_result',
+                    'tool_call_id': tool_call.id,
+                    'tool_name': tool_call.name,
+                    'plugin_name': metadata.get('plugin_name'),
+                    'virtual_tool': metadata.get('virtual_tool'),
+                }
+            )
+        if tool_call.name != 'delegate_agent':
+            return
+        child_results = metadata.get('child_results')
+        if isinstance(child_results, list):
+            for child in child_results:
+                if not isinstance(child, dict):
+                    continue
+                stream_events.append(
+                    {
+                        'type': 'delegate_subtask_result',
+                        'tool_call_id': tool_call.id,
+                        'group_id': metadata.get('group_id'),
+                        'label': child.get('label'),
+                        'index': child.get('index'),
+                        'session_id': child.get('session_id'),
+                        'stop_reason': child.get('stop_reason'),
+                        'tool_calls': child.get('tool_calls'),
+                        'turns': child.get('turns'),
+                        'resume_used': child.get('resume_used'),
+                        'resumed_from_session_id': child.get('resumed_from_session_id'),
+                    }
+                )
+        if metadata.get('group_id') is not None:
+            stream_events.append(
+                {
+                    'type': 'delegate_group_result',
+                    'tool_call_id': tool_call.id,
+                    'group_id': metadata.get('group_id'),
+                    'group_status': metadata.get('group_status'),
+                    'subtask_count': metadata.get('subtask_count'),
+                    'completed_children': metadata.get('completed_children'),
+                    'failed_children': metadata.get('failed_children'),
+                    'resumed_children': metadata.get('resumed_children'),
+                }
+            )
+
     def _preview_text(self, text: str, limit: int) -> str:
         normalized = ' '.join(text.split())
         if len(normalized) <= limit:
@@ -1597,12 +1813,31 @@ class LocalCodingAgent:
             lines.append(
                 f"- Latest compact boundary id: {latest_boundary.message_id or '(none)'}"
             )
+            depth = latest_boundary.metadata.get('compaction_depth')
+            if isinstance(depth, int) and not isinstance(depth, bool):
+                lines.append(f'- Latest compaction depth: {depth}')
+            compacted_lineages = latest_boundary.metadata.get('compacted_lineage_ids')
+            if isinstance(compacted_lineages, list) and compacted_lineages:
+                lines.append(f'- Latest compacted lineages: {len(compacted_lineages)}')
+            preserved_tail = latest_boundary.metadata.get('preserved_tail_ids')
+            if isinstance(preserved_tail, list) and preserved_tail:
+                lines.append(
+                    '- Latest preserved tail ids: '
+                    + ', '.join(str(item) for item in preserved_tail[:4])
+                )
         if snipped_messages:
             last_ids = [
                 message.message_id or '(none)'
                 for message in snipped_messages[-3:]
             ]
             lines.append(f"- Recent snipped ids: {', '.join(last_ids)}")
+            snipped_lineages = [
+                str(message.metadata.get('snipped_from_lineage_id'))
+                for message in snipped_messages[-3:]
+                if isinstance(message.metadata.get('snipped_from_lineage_id'), str)
+            ]
+            if snipped_lineages:
+                lines.append(f"- Recent snipped lineages: {', '.join(snipped_lineages)}")
         lines.extend(
             [
                 '',
@@ -1616,19 +1851,22 @@ class LocalCodingAgent:
         self,
         *,
         tool_name: str,
+        preflight_messages: tuple[str, ...],
         block_message: str | None,
         plugin_messages: tuple[str, ...],
     ) -> str | None:
-        if block_message is None and not plugin_messages:
+        if block_message is None and not plugin_messages and not preflight_messages:
             return None
         lines = [
             '<system-reminder>',
             f'Plugin tool runtime guidance for `{tool_name}`:',
         ]
+        for message in preflight_messages:
+            lines.append(f'- Before tool: {message}')
         if block_message is not None:
             lines.append(f'- Blocked: {block_message}')
         for message in plugin_messages:
-            lines.append(f'- {message}')
+            lines.append(f'- After result: {message}')
         lines.extend(
             [
                 '',
@@ -1638,6 +1876,11 @@ class LocalCodingAgent:
         )
         return '\n'.join(lines)
 
+    def _plugin_tool_preflight_messages(self, tool_name: str) -> tuple[str, ...]:
+        if self.plugin_runtime is None:
+            return ()
+        return self.plugin_runtime.tool_preflight_injections(tool_name)
+
     def _plugin_block_message(self, tool_name: str) -> str | None:
         if self.plugin_runtime is None:
             return None
@@ -1763,6 +2006,7 @@ class LocalCodingAgent:
 
     def _finalize_managed_agent(self, result: AgentRunResult) -> None:
         if self.managed_agent_id is None or self.agent_manager is None:
+            self.resume_source_session_id = None
             return
         self.agent_manager.finish_agent(
             self.managed_agent_id,
@@ -1772,6 +2016,7 @@ class LocalCodingAgent:
             tool_calls=result.tool_calls,
             stop_reason=result.stop_reason,
         )
+        self.resume_source_session_id = None
 
     def _apply_plugin_before_prompt_hooks(self, prompt: str) -> str:
         if self.plugin_runtime is None:

src/agent_session.py

@@ -114,6 +114,10 @@ class AgentSessionState:
                     _append_system_context(system_prompt_parts, state.system_context)
                 ),
                 blocks=_text_blocks('\n\n'.join(_append_system_context(system_prompt_parts, state.system_context))),
+                metadata=_initialize_message_metadata(
+                    role='system',
+                    message_id='system_0',
+                ),
             )
         )
         if state.user_context:
@@ -122,6 +126,10 @@ class AgentSessionState:
                     role='user',
                     content=_render_user_context_reminder(state.user_context),
                     blocks=_text_blocks(_render_user_context_reminder(state.user_context)),
+                    metadata=_initialize_message_metadata(
+                        role='user',
+                        message_id='user_context_0',
+                    ),
                 )
             )
         if user_prompt is not None:
@@ -130,6 +138,10 @@ class AgentSessionState:
                     role='user',
                     content=user_prompt,
                     blocks=_text_blocks(user_prompt),
+                    metadata=_initialize_message_metadata(
+                        role='user',
+                        message_id='user_0',
+                    ),
                 )
             )
         return state
@@ -152,6 +164,10 @@ class AgentSessionState:
                 message_id=message_id,
                 stop_reason=stop_reason,
                 usage=usage or UsageStats(),
+                metadata=_initialize_message_metadata(
+                    role='assistant',
+                    message_id=message_id or f'assistant_{len(self.messages)}',
+                ),
             )
         )
 
@@ -168,16 +184,29 @@ class AgentSessionState:
                 blocks=(),
                 message_id=message_id,
                 state='streaming',
+                metadata=_initialize_message_metadata(
+                    role='assistant',
+                    message_id=message_id or f'assistant_{len(self.messages)}',
+                ),
             )
         )
         return len(self.messages) - 1
 
     def append_assistant_delta(self, index: int, delta: str) -> None:
         message = self.messages[index]
+        merged_metadata = _record_mutation(
+            dict(message.metadata),
+            mutation_kind='assistant_delta_append',
+            previous_content=message.content,
+            previous_state=message.state,
+            previous_stop_reason=message.stop_reason,
+        )
+        merged_metadata = _advance_lineage_revision(merged_metadata)
         self.messages[index] = replace(
             message,
             content=message.content + delta,
             blocks=_assistant_blocks(message.content + delta, message.tool_calls),
+            metadata=merged_metadata,
         )
 
     def merge_assistant_tool_call_delta(
@@ -211,10 +240,19 @@ class AgentSessionState:
         if arguments_delta:
             current_arguments = function_block.get('arguments', '')
             function_block['arguments'] = f'{current_arguments}{arguments_delta}'
+        merged_metadata = _record_mutation(
+            dict(message.metadata),
+            mutation_kind='assistant_tool_call_delta',
+            previous_content=message.content,
+            previous_state=message.state,
+            previous_stop_reason=message.stop_reason,
+        )
+        merged_metadata = _advance_lineage_revision(merged_metadata)
         self.messages[index] = replace(
             message,
             tool_calls=tuple(tool_calls),
             blocks=_assistant_blocks(message.content, tuple(tool_calls)),
+            metadata=merged_metadata,
         )
 
     def finalize_assistant(
@@ -225,12 +263,21 @@ class AgentSessionState:
         usage: UsageStats | None = None,
     ) -> None:
         message = self.messages[index]
+        merged_metadata = _record_mutation(
+            dict(message.metadata),
+            mutation_kind='assistant_finalize',
+            previous_content=message.content,
+            previous_state=message.state,
+            previous_stop_reason=message.stop_reason,
+        )
+        merged_metadata = _advance_lineage_revision(merged_metadata)
         self.messages[index] = replace(
             message,
             state='final',
             stop_reason=finish_reason,
             usage=usage or message.usage,
             blocks=_assistant_blocks(message.content, message.tool_calls),
+            metadata=merged_metadata,
         )
 
     def append_user(
@@ -245,7 +292,11 @@ class AgentSessionState:
                 role='user',
                 content=content,
                 blocks=_text_blocks(content),
+                metadata=_initialize_message_metadata(
+                    role='user',
+                    message_id=message_id or f'user_{len(self.messages)}',
                     metadata=dict(metadata or {}),
+                ),
                 message_id=message_id,
             )
         )
@@ -258,6 +309,11 @@ class AgentSessionState:
                 name=name,
                 tool_call_id=tool_call_id,
                 blocks=_tool_blocks(name, tool_call_id, content),
+                metadata=_initialize_message_metadata(
+                    role='tool',
+                    message_id=f'tool_{len(self.messages)}',
+                    metadata={'tool_name': name, 'tool_call_id': tool_call_id},
+                ),
             )
         )
 
@@ -278,7 +334,15 @@ class AgentSessionState:
                 blocks=(),
                 message_id=message_id,
                 state='streaming',
-                metadata=dict(metadata or {}),
+                metadata=_initialize_message_metadata(
+                    role='tool',
+                    message_id=message_id or f'tool_{len(self.messages)}',
+                    metadata={
+                        'tool_name': name,
+                        'tool_call_id': tool_call_id,
+                        **dict(metadata or {}),
+                    },
+                ),
             )
         )
         return len(self.messages) - 1
@@ -292,6 +356,14 @@ class AgentSessionState:
     ) -> None:
         message = self.messages[index]
         merged_metadata = dict(message.metadata)
+        merged_metadata = _record_mutation(
+            merged_metadata,
+            mutation_kind='tool_delta_append',
+            previous_content=message.content,
+            previous_state=message.state,
+            previous_stop_reason=message.stop_reason,
+        )
+        merged_metadata = _advance_lineage_revision(merged_metadata)
         if metadata:
             merged_metadata.update(metadata)
         self.messages[index] = replace(
@@ -320,6 +392,7 @@ class AgentSessionState:
                 previous_state=message.state,
                 previous_stop_reason=message.stop_reason,
             )
+            merged_metadata = _advance_lineage_revision(merged_metadata)
         if metadata:
             merged_metadata.update(metadata)
         self.messages[index] = replace(
@@ -358,6 +431,7 @@ class AgentSessionState:
                 previous_state=message.state,
                 previous_stop_reason=message.stop_reason,
             )
+            merged_metadata = _advance_lineage_revision(merged_metadata)
         if metadata:
             merged_metadata.update(metadata)
         self.messages[index] = replace(
@@ -471,9 +545,64 @@ def _record_mutation(
     metadata['mutations'] = mutations
     metadata['mutation_count'] = len(mutations)
     metadata['last_mutation_kind'] = mutation_kind
+    totals = metadata.get('mutation_totals')
+    if not isinstance(totals, dict):
+        totals = {}
+    else:
+        totals = {
+            str(key): int(value)
+            for key, value in totals.items()
+            if isinstance(key, str) and not isinstance(value, bool) and isinstance(value, int)
+        }
+    totals[mutation_kind] = totals.get(mutation_kind, 0) + 1
+    metadata['mutation_totals'] = totals
     return metadata
 
 
+def _initialize_message_metadata(
+    *,
+    role: str,
+    message_id: str | None,
+    metadata: JSONDict | None = None,
+) -> JSONDict:
+    merged = dict(metadata or {})
+    lineage_id = merged.get('lineage_id')
+    if not isinstance(lineage_id, str) or not lineage_id:
+        if isinstance(message_id, str) and message_id:
+            lineage_id = message_id
+        else:
+            lineage_id = f'{role}_lineage'
+    revision = merged.get('revision')
+    if isinstance(revision, bool) or not isinstance(revision, int):
+        revision = 0
+    revision_count = merged.get('revision_count')
+    if isinstance(revision_count, bool) or not isinstance(revision_count, int):
+        revision_count = max(revision + 1, 1)
+    merged['lineage_id'] = lineage_id
+    merged['revision'] = revision
+    merged['revision_count'] = revision_count
+    merged.setdefault('message_role', role)
+    return merged
+
+
+def _advance_lineage_revision(metadata: JSONDict) -> JSONDict:
+    normalized = _initialize_message_metadata(
+        role=str(metadata.get('message_role', 'message')),
+        message_id=metadata.get('lineage_id') if isinstance(metadata.get('lineage_id'), str) else None,
+        metadata=metadata,
+    )
+    revision = normalized.get('revision', 0)
+    if isinstance(revision, bool) or not isinstance(revision, int):
+        revision = 0
+    revision += 1
+    normalized['revision'] = revision
+    revision_count = normalized.get('revision_count', 1)
+    if isinstance(revision_count, bool) or not isinstance(revision_count, int):
+        revision_count = 1
+    normalized['revision_count'] = max(revision_count, revision + 1)
+    return normalized
+
+
 def _text_blocks(text: str) -> tuple[JSONDict, ...]:
     if not text:
         return ()

src/agent_tools.py

@@ -240,16 +240,21 @@ def default_tool_registry() -> dict[str, AgentTool]:
                                         'prompt': {'type': 'string'},
                                         'label': {'type': 'string'},
                                         'max_turns': {'type': 'integer', 'minimum': 1, 'maximum': 20},
+                                        'resume_session_id': {'type': 'string'},
+                                        'session_id': {'type': 'string'},
                                     },
                                     'required': ['prompt'],
                                 },
                             ]
                         },
                     },
+                    'resume_session_id': {'type': 'string'},
+                    'session_id': {'type': 'string'},
                     'max_turns': {'type': 'integer', 'minimum': 1, 'maximum': 20},
                     'allow_write': {'type': 'boolean'},
                     'allow_shell': {'type': 'boolean'},
                     'include_parent_context': {'type': 'boolean'},
+                    'continue_on_error': {'type': 'boolean'},
                 },
             },
             handler=_delegate_agent_placeholder,

src/plugin_runtime.py

@@ -16,10 +16,20 @@ class PluginToolAlias:
 @dataclass(frozen=True)
 class PluginToolHook:
     tool_name: str
+    before_tool: str | None = None
     after_result: str | None = None
     block_message: str | None = None
 
 
+@dataclass(frozen=True)
+class PluginVirtualTool:
+    name: str
+    description: str
+    response_template: str
+    parameters: dict[str, Any] = field(default_factory=dict)
+    metadata: dict[str, Any] = field(default_factory=dict)
+
+
 @dataclass(frozen=True)
 class PluginManifest:
     name: str
@@ -29,6 +39,7 @@ class PluginManifest:
     tool_names: tuple[str, ...] = ()
     hook_names: tuple[str, ...] = ()
     tool_aliases: tuple[PluginToolAlias, ...] = ()
+    virtual_tools: tuple[PluginVirtualTool, ...] = ()
     tool_hooks: tuple[PluginToolHook, ...] = ()
     blocked_tools: tuple[str, ...] = ()
     before_prompt: str | None = None
@@ -69,6 +80,11 @@ class PluginRuntime:
                     'Tool aliases: '
                     + ', '.join(alias.name for alias in manifest.tool_aliases)
                 )
+            if manifest.virtual_tools:
+                lines.append(
+                    'Virtual tools: '
+                    + ', '.join(tool.name for tool in manifest.virtual_tools)
+                )
             if manifest.blocked_tools:
                 lines.append(
                     'Blocked tools: '
@@ -114,6 +130,26 @@ class PluginRuntime:
                 )
         return aliases
 
+    def register_virtual_tools(
+        self,
+        base_registry: dict[str, Any] | None = None,
+    ) -> dict[str, Any]:
+        from .agent_tools import AgentTool
+
+        tools: dict[str, AgentTool] = {}
+        occupied = set(base_registry or {})
+        for manifest in self.manifests:
+            for tool in manifest.virtual_tools:
+                if tool.name in occupied or tool.name in tools:
+                    continue
+                tools[tool.name] = AgentTool(
+                    name=tool.name,
+                    description=tool.description,
+                    parameters=tool.parameters or {'type': 'object', 'properties': {}},
+                    handler=_build_virtual_tool_handler(manifest.name, tool),
+                )
+        return tools
+
     def blocked_tool_message(self, tool_name: str) -> str | None:
         for manifest in self.manifests:
             if tool_name in manifest.blocked_tools:
@@ -123,6 +159,14 @@ class PluginRuntime:
                     return hook.block_message
         return None
 
+    def tool_preflight_injections(self, tool_name: str) -> tuple[str, ...]:
+        messages: list[str] = []
+        for manifest in self.manifests:
+            for hook in manifest.tool_hooks:
+                if hook.tool_name == tool_name and hook.before_tool:
+                    messages.append(f'{manifest.name}: {hook.before_tool}')
+        return tuple(messages)
+
     def tool_result_injections(self, tool_name: str) -> tuple[str, ...]:
         messages: list[str] = []
         for manifest in self.manifests:
@@ -145,6 +189,8 @@ class PluginRuntime:
                 details.append(f'hooks={len(manifest.hook_names)}')
             if manifest.tool_aliases:
                 details.append(f'aliases={len(manifest.tool_aliases)}')
+            if manifest.virtual_tools:
+                details.append(f'virtual_tools={len(manifest.virtual_tools)}')
             if manifest.blocked_tools:
                 details.append(f'blocked={len(manifest.blocked_tools)}')
             if manifest.tool_hooks:
@@ -211,6 +257,7 @@ def _load_manifest(path: Path) -> PluginManifest | None:
         tool_names=_extract_string_tuple(payload.get('tools')),
         hook_names=hook_names,
         tool_aliases=_extract_tool_aliases(payload),
+        virtual_tools=_extract_virtual_tools(payload),
         tool_hooks=_extract_tool_hooks(payload),
         blocked_tools=_extract_string_tuple(
             payload.get('blocked_tools')
@@ -303,6 +350,9 @@ def _extract_tool_hooks(payload: dict[str, Any]) -> tuple[PluginToolHook, ...]:
                 continue
             if not isinstance(value, dict):
                 continue
+            before_tool = value.get('beforeTool')
+            if before_tool is None:
+                before_tool = value.get('before_tool')
             after_result = value.get('afterResult')
             if after_result is None:
                 after_result = value.get('after_result')
@@ -312,8 +362,80 @@ def _extract_tool_hooks(payload: dict[str, Any]) -> tuple[PluginToolHook, ...]:
             hooks.append(
                 PluginToolHook(
                     tool_name=tool_name.strip(),
+                    before_tool=_optional_string(before_tool),
                     after_result=_optional_string(after_result),
                     block_message=_optional_string(block_message),
                 )
             )
     return tuple(hooks)
+
+
+def _extract_virtual_tools(payload: dict[str, Any]) -> tuple[PluginVirtualTool, ...]:
+    raw_tools = payload.get('virtual_tools')
+    if raw_tools is None:
+        raw_tools = payload.get('virtualTools')
+    if raw_tools is None:
+        raw_tools = payload.get('runtimeTools')
+    tools: list[PluginVirtualTool] = []
+    if isinstance(raw_tools, list):
+        for item in raw_tools:
+            if not isinstance(item, dict):
+                continue
+            name = _optional_string(item.get('name'))
+            description = _optional_string(item.get('description'))
+            response_template = item.get('responseTemplate')
+            if response_template is None:
+                response_template = item.get('response_template')
+            if response_template is None:
+                response_template = item.get('response')
+            response_text = _optional_string(response_template)
+            parameters = item.get('parameters')
+            metadata = item.get('metadata')
+            if not name or not description or not response_text:
+                continue
+            tools.append(
+                PluginVirtualTool(
+                    name=name,
+                    description=description,
+                    response_template=response_text,
+                    parameters=dict(parameters) if isinstance(parameters, dict) else {},
+                    metadata=dict(metadata) if isinstance(metadata, dict) else {},
+                )
+            )
+    return tuple(tools)
+
+
+def _build_virtual_tool_handler(
+    plugin_name: str,
+    tool: PluginVirtualTool,
+):
+    def _handler(arguments: dict[str, Any], context):  # noqa: ANN001
+        rendered = _render_virtual_tool_response(tool.response_template, arguments)
+        metadata = {
+            'action': 'plugin_virtual_tool',
+            'plugin_name': plugin_name,
+            'virtual_tool': tool.name,
+            **tool.metadata,
+        }
+        return rendered, metadata
+
+    return _handler
+
+
+def _render_virtual_tool_response(
+    template: str,
+    arguments: dict[str, Any],
+) -> str:
+    normalized = {
+        key: json.dumps(value, ensure_ascii=True) if isinstance(value, (dict, list)) else str(value)
+        for key, value in arguments.items()
+    }
+    try:
+        return template.format_map(_SafeTemplateDict(normalized))
+    except Exception:
+        return template
+
+
+class _SafeTemplateDict(dict[str, str]):
+    def __missing__(self, key: str) -> str:
+        return '{' + key + '}'

src/query_engine.py

@@ -55,7 +55,17 @@ class QueryEnginePort:
     plugin_runtime: PluginRuntime | None = None
     runtime_event_counts: dict[str, int] = field(default_factory=dict)
     runtime_message_kind_counts: dict[str, int] = field(default_factory=dict)
+    runtime_mutation_counts: dict[str, int] = field(default_factory=dict)
+    runtime_group_status_counts: dict[str, int] = field(default_factory=dict)
+    runtime_child_stop_reason_counts: dict[str, int] = field(default_factory=dict)
+    runtime_resumed_children: int = 0
+    runtime_context_reduction: dict[str, int] = field(default_factory=dict)
+    runtime_lineage_stats: dict[str, int] = field(default_factory=dict)
     runtime_transcript_size: int = 0
+    _runtime_seen_lineages: set[str] = field(default_factory=set, init=False, repr=False)
+    _runtime_revised_lineages: set[str] = field(default_factory=set, init=False, repr=False)
+    _runtime_tombstoned_lineages: set[str] = field(default_factory=set, init=False, repr=False)
+    _runtime_compacted_lineages: set[str] = field(default_factory=set, init=False, repr=False)
     last_turn: TurnResult | None = field(default=None, init=False, repr=False)
 
     @classmethod
@@ -180,6 +190,7 @@ class QueryEnginePort:
         if self.config.use_runtime_agent:
             for event in result.events:
                 yield event
+            yield self._runtime_summary_event()
             yield {
                 'type': 'message_stop',
                 'usage': {
@@ -217,7 +228,7 @@ class QueryEnginePort:
         path = save_session(
             StoredSession(
                 session_id=self.session_id,
-                messages=tuple(self.mutable_messages),
+                messages=self.transcript_store.replay(),
                 input_tokens=self.total_usage.input_tokens,
                 output_tokens=self.total_usage.output_tokens,
             )
@@ -247,6 +258,7 @@ class QueryEnginePort:
             f'Transcript flushed: {self.transcript_store.flushed}',
             f'Real runtime agent mode: {self.config.use_runtime_agent}',
         ]
+        sections.extend(['', '## Transcript Store', *self.transcript_store.summary_lines()])
         if self.plugin_runtime is not None:
             sections.extend(['', '## Plugin Runtime', self.plugin_runtime.render_summary()])
         if self.runtime_agent is not None and self.runtime_agent.agent_manager is not None:
@@ -264,6 +276,38 @@ class QueryEnginePort:
                 f'- {name}={count}'
                 for name, count in sorted(self.runtime_message_kind_counts.items())
             )
+        if self.runtime_mutation_counts:
+            sections.extend(['', '## Runtime Mutations'])
+            sections.extend(
+                f'- {name}={count}'
+                for name, count in sorted(self.runtime_mutation_counts.items())
+            )
+        if self.runtime_group_status_counts or self.runtime_child_stop_reason_counts:
+            sections.extend(['', '## Runtime Orchestration'])
+            if self.runtime_group_status_counts:
+                sections.extend(
+                    f'- group_status:{name}={count}'
+                    for name, count in sorted(self.runtime_group_status_counts.items())
+                )
+            if self.runtime_child_stop_reason_counts:
+                sections.extend(
+                    f'- child_stop:{name}={count}'
+                    for name, count in sorted(self.runtime_child_stop_reason_counts.items())
+                )
+            if self.runtime_resumed_children:
+                sections.append(f'- resumed_children={self.runtime_resumed_children}')
+        if self.runtime_context_reduction:
+            sections.extend(['', '## Runtime Context Reduction'])
+            sections.extend(
+                f'- {name}={count}'
+                for name, count in sorted(self.runtime_context_reduction.items())
+            )
+        if self.runtime_lineage_stats:
+            sections.extend(['', '## Runtime Lineage'])
+            sections.extend(
+                f'- {name}={count}'
+                for name, count in sorted(self.runtime_lineage_stats.items())
+            )
         if self.last_turn is not None:
             sections.extend(
                 [
@@ -303,8 +347,8 @@ class QueryEnginePort:
         denied_tools: tuple[PermissionDenial, ...],
     ) -> None:
         self.mutable_messages.append(prompt)
-        self.transcript_store.append(prompt)
+        self.transcript_store.append(prompt, kind='prompt')
-        self.transcript_store.append(turn.output)
+        self.transcript_store.append(turn.output, kind='output')
         if self.config.use_runtime_agent:
             self._record_runtime_turn(turn)
         self.permission_denials.extend(denied_tools)
@@ -334,7 +378,22 @@ class QueryEnginePort:
             self.runtime_event_counts[event_type] = (
                 self.runtime_event_counts.get(event_type, 0) + 1
             )
+            if event_type == 'delegate_group_result':
+                group_status = event.get('group_status')
+                if isinstance(group_status, str) and group_status:
+                    self.runtime_group_status_counts[group_status] = (
+                        self.runtime_group_status_counts.get(group_status, 0) + 1
+                    )
+            elif event_type == 'delegate_subtask_result':
+                stop_reason = event.get('stop_reason')
+                if isinstance(stop_reason, str) and stop_reason:
+                    self.runtime_child_stop_reason_counts[stop_reason] = (
+                        self.runtime_child_stop_reason_counts.get(stop_reason, 0) + 1
+                    )
+                if bool(event.get('resume_used')):
+                    self.runtime_resumed_children += 1
         kind_counts: dict[str, int] = {}
+        mutation_counts: dict[str, int] = {}
         for entry in turn.transcript:
             if not isinstance(entry, dict):
                 continue
@@ -342,20 +401,76 @@ class QueryEnginePort:
             if not isinstance(metadata, dict):
                 continue
             kind = metadata.get('kind')
-            if not isinstance(kind, str) or not kind:
+            if isinstance(kind, str) and kind:
-                continue
                 kind_counts[kind] = kind_counts.get(kind, 0) + 1
                 self.runtime_message_kind_counts[kind] = (
                     self.runtime_message_kind_counts.get(kind, 0) + 1
                 )
-        summary = self._summarize_runtime_turn(event_counts, kind_counts, len(turn.transcript))
+            mutation_totals = metadata.get('mutation_totals')
+            if isinstance(mutation_totals, dict):
+                for mutation_kind, count in mutation_totals.items():
+                    if (
+                        not isinstance(mutation_kind, str)
+                        or not mutation_kind
+                        or isinstance(count, bool)
+                        or not isinstance(count, int)
+                        or count <= 0
+                    ):
+                        continue
+                    mutation_counts[mutation_kind] = mutation_counts.get(mutation_kind, 0) + count
+                    self.runtime_mutation_counts[mutation_kind] = (
+                        self.runtime_mutation_counts.get(mutation_kind, 0) + count
+                    )
+            else:
+                mutations = metadata.get('mutations')
+                if isinstance(mutations, list):
+                    for mutation in mutations:
+                        if not isinstance(mutation, dict):
+                            continue
+                        mutation_kind = mutation.get('kind')
+                        if not isinstance(mutation_kind, str) or not mutation_kind:
+                            continue
+                        mutation_counts[mutation_kind] = mutation_counts.get(mutation_kind, 0) + 1
+                        self.runtime_mutation_counts[mutation_kind] = (
+                            self.runtime_mutation_counts.get(mutation_kind, 0) + 1
+                        )
+            self._record_context_reduction(metadata)
+            self._record_lineage(metadata)
+        summary = self._summarize_runtime_turn(
+            event_counts,
+            kind_counts,
+            mutation_counts,
+            len(turn.transcript),
+        )
         if summary:
-            self.transcript_store.append(summary)
+            self.transcript_store.append(
+                summary,
+                kind='runtime_summary',
+                metadata={
+                    'runtime_event_counts': dict(event_counts),
+                    'runtime_kind_counts': dict(kind_counts),
+                    'runtime_mutation_counts': dict(mutation_counts),
+                    'runtime_transcript_size': len(turn.transcript),
+                },
+            )
+        if event_counts:
+            self.transcript_store.append(
+                json.dumps(event_counts, sort_keys=True),
+                kind='runtime_events',
+                metadata={'counts': dict(event_counts)},
+            )
+        if kind_counts:
+            self.transcript_store.append(
+                json.dumps(kind_counts, sort_keys=True),
+                kind='runtime_message_kinds',
+                metadata={'counts': dict(kind_counts)},
+            )
 
     def _summarize_runtime_turn(
         self,
         event_counts: dict[str, int],
         kind_counts: dict[str, int],
+        mutation_counts: dict[str, int],
         transcript_size: int,
     ) -> str:
         parts = [f'runtime_transcript={transcript_size}']
@@ -375,4 +490,116 @@ class QueryEnginePort:
                     for name, count in sorted(kind_counts.items())
                 )
             )
+        if mutation_counts:
+            parts.append(
+                'mutations='
+                + ', '.join(
+                    f'{name}:{count}'
+                    for name, count in sorted(mutation_counts.items())
+                )
+            )
         return '[runtime] ' + ' | '.join(parts)
+
+    def _runtime_summary_event(self) -> dict[str, object]:
+        return {
+            'type': 'runtime_summary',
+            'runtime_event_counts': dict(self.runtime_event_counts),
+            'runtime_message_kind_counts': dict(self.runtime_message_kind_counts),
+            'runtime_mutation_counts': dict(self.runtime_mutation_counts),
+            'runtime_group_status_counts': dict(self.runtime_group_status_counts),
+            'runtime_child_stop_reason_counts': dict(self.runtime_child_stop_reason_counts),
+            'runtime_resumed_children': self.runtime_resumed_children,
+            'runtime_context_reduction': dict(self.runtime_context_reduction),
+            'runtime_lineage_stats': dict(self.runtime_lineage_stats),
+            'runtime_transcript_size': self.runtime_transcript_size,
+            'transcript_store_entries': len(self.transcript_store.entries),
+            'transcript_store_compactions': self.transcript_store.compaction_count,
+        }
+
+    def _record_context_reduction(self, metadata: dict[str, object]) -> None:
+        kind = metadata.get('kind')
+        if kind == 'compact_boundary':
+            self.runtime_context_reduction['compact_boundaries'] = (
+                self.runtime_context_reduction.get('compact_boundaries', 0) + 1
+            )
+            depth = metadata.get('compaction_depth')
+            if isinstance(depth, int) and not isinstance(depth, bool):
+                current = self.runtime_context_reduction.get('max_compaction_depth', 0)
+                self.runtime_context_reduction['max_compaction_depth'] = max(current, depth)
+            nested = metadata.get('nested_compaction_count')
+            if isinstance(nested, int) and not isinstance(nested, bool):
+                self.runtime_context_reduction['nested_compaction_count'] = (
+                    self.runtime_context_reduction.get('nested_compaction_count', 0) + nested
+                )
+            preserved_tail_count = metadata.get('preserved_tail_count')
+            if isinstance(preserved_tail_count, int) and not isinstance(preserved_tail_count, bool):
+                self.runtime_context_reduction['preserved_tail_messages'] = (
+                    self.runtime_context_reduction.get('preserved_tail_messages', 0)
+                    + preserved_tail_count
+                )
+            compacted_lineage_ids = metadata.get('compacted_lineage_ids')
+            if isinstance(compacted_lineage_ids, list):
+                self.runtime_context_reduction['compacted_lineages'] = (
+                    self.runtime_context_reduction.get('compacted_lineages', 0)
+                    + len(
+                        [
+                            lineage_id for lineage_id in compacted_lineage_ids
+                            if isinstance(lineage_id, str) and lineage_id
+                        ]
+                    )
+                )
+        elif kind == 'snipped_message':
+            self.runtime_context_reduction['snipped_messages'] = (
+                self.runtime_context_reduction.get('snipped_messages', 0) + 1
+            )
+            revision = metadata.get('snipped_from_revision')
+            if isinstance(revision, int) and not isinstance(revision, bool) and revision > 0:
+                self.runtime_context_reduction['snipped_revised_messages'] = (
+                    self.runtime_context_reduction.get('snipped_revised_messages', 0) + 1
+                )
+
+    def _record_lineage(self, metadata: dict[str, object]) -> None:
+        lineage_id = metadata.get('lineage_id')
+        if isinstance(lineage_id, str) and lineage_id:
+            self._runtime_seen_lineages.add(lineage_id)
+            revision = metadata.get('revision')
+            if isinstance(revision, int) and not isinstance(revision, bool):
+                current = self.runtime_lineage_stats.get('max_revision', 0)
+                self.runtime_lineage_stats['max_revision'] = max(current, revision)
+                if revision > 0:
+                    self._runtime_revised_lineages.add(lineage_id)
+            revision_count = metadata.get('revision_count')
+            if isinstance(revision_count, int) and not isinstance(revision_count, bool):
+                current = self.runtime_lineage_stats.get('max_revision_count', 0)
+                self.runtime_lineage_stats['max_revision_count'] = max(current, revision_count)
+
+        kind = metadata.get('kind')
+        if kind == 'snipped_message':
+            source_lineage = metadata.get('snipped_from_lineage_id')
+            if isinstance(source_lineage, str) and source_lineage:
+                self._runtime_tombstoned_lineages.add(source_lineage)
+        elif kind == 'compact_boundary':
+            compacted_lineage_ids = metadata.get('compacted_lineage_ids')
+            if isinstance(compacted_lineage_ids, list):
+                for source_lineage in compacted_lineage_ids:
+                    if isinstance(source_lineage, str) and source_lineage:
+                        self._runtime_compacted_lineages.add(source_lineage)
+            max_source_revision = metadata.get('max_source_revision')
+            if (
+                isinstance(max_source_revision, int)
+                and not isinstance(max_source_revision, bool)
+            ):
+                current = self.runtime_lineage_stats.get('max_source_revision', 0)
+                self.runtime_lineage_stats['max_source_revision'] = max(
+                    current,
+                    max_source_revision,
+                )
+
+        self.runtime_lineage_stats['seen_lineages'] = len(self._runtime_seen_lineages)
+        self.runtime_lineage_stats['revised_lineages'] = len(self._runtime_revised_lineages)
+        self.runtime_lineage_stats['tombstoned_lineages'] = len(
+            self._runtime_tombstoned_lineages
+        )
+        self.runtime_lineage_stats['compacted_lineages'] = len(
+            self._runtime_compacted_lineages
+        )

src/transcript.py

@@ -1,23 +1,131 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
+from typing import Any
+
+
+JSONDict = dict[str, Any]
+
+
+@dataclass(frozen=True)
+class TranscriptEntry:
+    content: str
+    kind: str = 'message'
+    metadata: JSONDict = field(default_factory=dict)
 
 
 @dataclass
 class TranscriptStore:
-    entries: list[str] = field(default_factory=list)
+    entries: list[TranscriptEntry] = field(default_factory=list)
     flushed: bool = False
+    compaction_count: int = 0
 
-    def append(self, entry: str) -> None:
+    def __post_init__(self) -> None:
-        self.entries.append(entry)
+        normalized: list[TranscriptEntry] = []
+        for entry in self.entries:
+            if isinstance(entry, TranscriptEntry):
+                normalized.append(entry)
+            elif isinstance(entry, str):
+                normalized.append(TranscriptEntry(content=entry))
+        self.entries = normalized
+
+    def append(
+        self,
+        entry: str,
+        *,
+        kind: str = 'message',
+        metadata: JSONDict | None = None,
+    ) -> None:
+        self.entries.append(
+            TranscriptEntry(
+                content=entry,
+                kind=kind,
+                metadata=dict(metadata or {}),
+            )
+        )
         self.flushed = False
 
     def compact(self, keep_last: int = 10) -> None:
-        if len(self.entries) > keep_last:
+        if len(self.entries) <= keep_last:
-            self.entries[:] = self.entries[-keep_last:]
+            return
+        trimmed = self.entries[:-keep_last]
+        kept = self.entries[-keep_last:]
+        self.compaction_count += 1
+        summary_metadata = {
+            'kind': 'compact_summary',
+            'compaction_index': self.compaction_count,
+            'compacted_entries': len(trimmed),
+            'compacted_kinds': self._kind_counts(trimmed),
+        }
+        summary = TranscriptEntry(
+            content=self._render_compaction_summary(trimmed, self.compaction_count),
+            kind='compact_summary',
+            metadata=summary_metadata,
+        )
+        self.entries[:] = [summary, *kept]
 
     def replay(self) -> tuple[str, ...]:
-        return tuple(self.entries)
+        return tuple(entry.content for entry in self.entries)
 
     def flush(self) -> None:
         self.flushed = True
+
+    def summary_lines(self) -> list[str]:
+        lines = [
+            f'- Transcript entries: {len(self.entries)}',
+            f'- Transcript compactions: {self.compaction_count}',
+        ]
+        kind_counts = self._kind_counts(self.entries)
+        if kind_counts:
+            lines.append(
+                '- Transcript kinds: '
+                + ', '.join(
+                    f'{name}={count}' for name, count in sorted(kind_counts.items())
+                )
+            )
+        return lines
+
+    def structured_replay(self) -> tuple[JSONDict, ...]:
+        return tuple(
+            {
+                'kind': entry.kind,
+                'content': entry.content,
+                'metadata': dict(entry.metadata),
+            }
+            for entry in self.entries
+        )
+
+    def _render_compaction_summary(
+        self,
+        trimmed: list[TranscriptEntry],
+        compaction_index: int,
+    ) -> str:
+        lines = [
+            f'[transcript-compaction {compaction_index}]',
+            f'Compacted {len(trimmed)} older transcript entries.',
+        ]
+        kind_counts = self._kind_counts(trimmed)
+        if kind_counts:
+            lines.append(
+                'Kinds: '
+                + ', '.join(
+                    f'{name}={count}' for name, count in sorted(kind_counts.items())
+                )
+            )
+        previews: list[str] = []
+        for entry in trimmed[-3:]:
+            preview = ' '.join(entry.content.split())
+            if len(preview) > 72:
+                preview = preview[:69] + '...'
+            previews.append(f'{entry.kind}: {preview or "(empty)"}')
+        if previews:
+            lines.append('Recent compacted previews:')
+            lines.extend(f'- {preview}' for preview in previews)
+        return '\n'.join(lines)
+
+    @staticmethod
+    def _kind_counts(entries: list[TranscriptEntry]) -> JSONDict:
+        counts: dict[str, int] = {}
+        for entry in entries:
+            counts[entry.kind] = counts.get(entry.kind, 0) + 1
+        return counts

tests/test_agent_runtime.py

@@ -362,6 +362,14 @@ class AgentRuntimeTests(unittest.TestCase):
         self.assertIsNotNone(result.scratchpad_directory)
         assert result.scratchpad_directory is not None
         self.assertTrue(Path(result.scratchpad_directory).is_dir())
+        assistant_messages = [
+            message for message in result.transcript if message.get('role') == 'assistant'
+        ]
+        self.assertEqual(len(assistant_messages), 1)
+        metadata = assistant_messages[0].get('metadata', {})
+        mutation_totals = metadata.get('mutation_totals', {})
+        self.assertGreaterEqual(mutation_totals.get('assistant_delta_append', 0), 2)
+        self.assertEqual(mutation_totals.get('assistant_finalize', 0), 1)
 
     def test_agent_streams_tool_calls_and_reconstructs_arguments(self) -> None:
         responses = [
@@ -439,6 +447,15 @@ class AgentRuntimeTests(unittest.TestCase):
         self.assertEqual(result.usage.output_tokens, 6)
         assistant_messages = [message for message in result.transcript if message.get('role') == 'assistant']
         self.assertTrue(any(message.get('tool_calls') for message in assistant_messages))
+        assistant_with_tool = next(
+            message
+            for message in assistant_messages
+            if message.get('tool_calls')
+        )
+        metadata = assistant_with_tool.get('metadata', {})
+        mutation_totals = metadata.get('mutation_totals', {})
+        self.assertGreaterEqual(mutation_totals.get('assistant_tool_call_delta', 0), 2)
+        self.assertEqual(mutation_totals.get('assistant_finalize', 0), 1)
 
     def test_transcript_entries_include_structured_blocks(self) -> None:
         responses = [
@@ -578,6 +595,10 @@ class AgentRuntimeTests(unittest.TestCase):
             if message.get('metadata', {}).get('kind') == 'compact_boundary'
         ]
         self.assertEqual(len(transcript_compact_messages), 1)
+        compact_metadata = transcript_compact_messages[0].get('metadata', {})
+        self.assertEqual(compact_metadata.get('compaction_depth'), 1)
+        self.assertEqual(compact_metadata.get('nested_compaction_count'), 0)
+        self.assertIn('preserved_tail_ids', compact_metadata)
 
     def test_agent_enforces_total_token_budget(self) -> None:
         responses = [
@@ -1386,6 +1407,9 @@ class AgentRuntimeTests(unittest.TestCase):
         self.assertEqual(len(metadata.get('child_session_ids', [])), 2)
         self.assertEqual(len(metadata.get('child_results', [])), 2)
         self.assertIn('Delegated agent completed 2 sequential subtasks.', tool_messages[0].get('content', ''))
+        self.assertTrue(any(event.get('type') == 'delegate_group_result' for event in result.events))
+        child_events = [event for event in result.events if event.get('type') == 'delegate_subtask_result']
+        self.assertEqual(len(child_events), 2)
         second_child_request = recorded_payloads[2]['messages']
         assert isinstance(second_child_request, list)
         self.assertTrue(
@@ -1497,6 +1521,153 @@ class AgentRuntimeTests(unittest.TestCase):
         summary = '\n'.join(manager.summary_lines())
         self.assertIn(f'group={group.group_id}', summary)
 
+    def test_agent_can_delegate_into_resumed_child_session(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Seed child result.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 5, 'completion_tokens': 2},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Delegating into a resumed child session.',
+                            'tool_calls': [
+                                {
+                                    'id': 'call_1',
+                                    'type': 'function',
+                                    'function': {
+                                        'name': 'delegate_agent',
+                                        'arguments': '{}',
+                                    },
+                                }
+                            ],
+                        },
+                        'finish_reason': 'tool_calls',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Resumed child result.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 6, 'completion_tokens': 2},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Parent completed after resumed child.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 7, 'completion_tokens': 2},
+            },
+        ]
+        recorded_payloads: list[dict[str, object]] = []
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            session_dir = workspace / '.port_sessions' / 'agent'
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_recording_urlopen_side_effect(responses, recorded_payloads),
+            ):
+                seed_agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(
+                        cwd=workspace,
+                        session_directory=session_dir,
+                    ),
+                )
+                seeded = seed_agent.run('Seed the delegated child')
+                resumed_child_id = seeded.session_id or ''
+
+                delegate_arguments = json.dumps(
+                    {
+                        'subtasks': [
+                            {
+                                'label': 'resume_child',
+                                'prompt': 'Continue the delegated child.',
+                                'resume_session_id': resumed_child_id,
+                                'max_turns': 2,
+                            }
+                        ],
+                        'max_turns': 2,
+                    }
+                )
+                responses[1]['choices'][0]['message']['tool_calls'][0]['function']['arguments'] = delegate_arguments
+
+                parent_agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(
+                        cwd=workspace,
+                        session_directory=session_dir,
+                    ),
+                )
+                result = parent_agent.run('Delegate into the resumed child')
+
+        self.assertEqual(result.final_output, 'Parent completed after resumed child.')
+        tool_messages = [message for message in result.transcript if message.get('role') == 'tool']
+        self.assertEqual(len(tool_messages), 1)
+        metadata = tool_messages[0].get('metadata', {})
+        self.assertEqual(metadata.get('resumed_children'), 1)
+        child_results = metadata.get('child_results', [])
+        self.assertEqual(len(child_results), 1)
+        self.assertEqual(child_results[0].get('resume_used'), True)
+        self.assertEqual(child_results[0].get('resumed_from_session_id'), resumed_child_id)
+        self.assertTrue(
+            any(
+                event.get('type') == 'delegate_subtask_result'
+                and event.get('resume_used')
+                for event in result.events
+            )
+        )
+        resumed_child_messages = recorded_payloads[2]['messages']
+        assert isinstance(resumed_child_messages, list)
+        resumed_contents = [
+            message.get('content')
+            for message in resumed_child_messages
+            if isinstance(message, dict)
+        ]
+        self.assertIn('Seed the delegated child', resumed_contents)
+        self.assertIn('Seed child result.', resumed_contents)
+        self.assertIn('Continue the delegated child.', resumed_contents)
+        manager = parent_agent.agent_manager
+        assert manager is not None
+        child_records = [
+            record
+            for record in manager.completed_records()
+            if record.parent_agent_id == parent_agent.managed_agent_id
+        ]
+        self.assertEqual(len(child_records), 1)
+        self.assertEqual(child_records[0].resumed_from_session_id, resumed_child_id)
+        summary = '\n'.join(manager.summary_lines())
+        self.assertIn(f'resumed_from={resumed_child_id}', summary)
+
     def test_agent_enforces_reasoning_token_budget(self) -> None:
         responses = [
             {

tests/test_query_engine_runtime.py

@@ -10,7 +10,7 @@ from src.agent_runtime import LocalCodingAgent
 from src.agent_types import AgentRuntimeConfig, ModelConfig
 from src.openai_compat import OpenAICompatClient
 from src.plugin_runtime import PluginRuntime
-from src.query_engine import QueryEnginePort
+from src.query_engine import QueryEngineConfig, QueryEnginePort
 
 
 class FakeHTTPResponse:
@@ -27,6 +27,27 @@ class FakeHTTPResponse:
         return None
 
 
+class FakeStreamingHTTPResponse:
+    def __init__(self, payloads: list[dict[str, object]]) -> None:
+        self.lines: list[bytes] = []
+        for payload in payloads:
+            chunk = f'data: {json.dumps(payload)}\n\n'
+            self.lines.extend(part.encode('utf-8') for part in chunk.splitlines(keepends=True))
+        done_chunk = 'data: [DONE]\n\n'
+        self.lines.extend(part.encode('utf-8') for part in done_chunk.splitlines(keepends=True))
+
+    def readline(self) -> bytes:
+        if not self.lines:
+            return b''
+        return self.lines.pop(0)
+
+    def __enter__(self) -> 'FakeStreamingHTTPResponse':
+        return self
+
+    def __exit__(self, exc_type, exc, tb) -> None:
+        return None
+
+
 def make_recording_urlopen_side_effect(
     responses: list[dict[str, object]],
     recorded_payloads: list[dict[str, object]],
@@ -50,6 +71,17 @@ def make_urlopen_side_effect(responses: list[dict[str, object]]):
     return _fake_urlopen
 
 
+def make_streaming_urlopen_side_effect(
+    responses: list[list[dict[str, object]]],
+):
+    queued = [FakeStreamingHTTPResponse(payloads) for payloads in responses]
+
+    def _fake_urlopen(request_obj, timeout=None):  # noqa: ANN001
+        return queued.pop(0)
+
+    return _fake_urlopen
+
+
 class QueryEngineRuntimeTests(unittest.TestCase):
     def test_plugin_runtime_discovers_local_manifest(self) -> None:
         with tempfile.TemporaryDirectory() as tmp_dir:
@@ -249,6 +281,112 @@ class QueryEngineRuntimeTests(unittest.TestCase):
             )
         )
 
+    def test_runtime_agent_executes_plugin_virtual_tool(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Calling the plugin virtual tool.',
+                            'tool_calls': [
+                                {
+                                    'id': 'call_1',
+                                    'type': 'function',
+                                    'function': {
+                                        'name': 'demo_virtual',
+                                        'arguments': '{"topic": "plugins"}',
+                                    },
+                                }
+                            ],
+                        },
+                        'finish_reason': 'tool_calls',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Plugin virtual tool completed.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 7, 'completion_tokens': 2},
+            },
+        ]
+        recorded_payloads: list[dict[str, object]] = []
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            plugin_dir = workspace / 'plugins' / 'demo'
+            plugin_dir.mkdir(parents=True)
+            (plugin_dir / 'plugin.json').write_text(
+                json.dumps(
+                    {
+                        'name': 'demo-plugin',
+                        'virtualTools': [
+                            {
+                                'name': 'demo_virtual',
+                                'description': 'Return a rendered plugin response.',
+                                'responseTemplate': 'Plugin says {topic}',
+                                'parameters': {
+                                    'type': 'object',
+                                    'properties': {'topic': {'type': 'string'}},
+                                    'required': ['topic'],
+                                },
+                            }
+                        ],
+                        'toolHooks': {
+                            'demo_virtual': {
+                                'afterResult': 'Use the virtual tool result in the next reply.',
+                            }
+                        },
+                    }
+                ),
+                encoding='utf-8',
+            )
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_recording_urlopen_side_effect(responses, recorded_payloads),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(cwd=workspace),
+                )
+                result = agent.run('Use the plugin virtual tool')
+
+        self.assertEqual(result.final_output, 'Plugin virtual tool completed.')
+        self.assertTrue(
+            any(event.get('type') == 'plugin_virtual_tool_result' for event in result.events)
+        )
+        tool_names = [
+            item['function']['name']
+            for item in recorded_payloads[0]['tools']
+            if isinstance(item, dict) and isinstance(item.get('function'), dict)
+        ]
+        self.assertIn('demo_virtual', tool_names)
+        tool_messages = [message for message in result.transcript if message.get('role') == 'tool']
+        self.assertEqual(len(tool_messages), 1)
+        metadata = tool_messages[0].get('metadata', {})
+        self.assertEqual(metadata.get('action'), 'plugin_virtual_tool')
+        self.assertEqual(metadata.get('plugin_name'), 'demo-plugin')
+        self.assertEqual(metadata.get('virtual_tool'), 'demo_virtual')
+        second_messages = recorded_payloads[1]['messages']
+        assert isinstance(second_messages, list)
+        self.assertTrue(
+            any(
+                isinstance(message, dict)
+                and 'Use the virtual tool result in the next reply.' in str(message.get('content', ''))
+                for message in second_messages
+            )
+        )
+
     def test_runtime_agent_injects_plugin_tool_runtime_guidance(self) -> None:
         responses = [
             {
@@ -337,6 +475,93 @@ class QueryEngineRuntimeTests(unittest.TestCase):
             )
         )
 
+    def test_runtime_agent_supports_plugin_before_tool_guidance(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Reading through plugin guidance.',
+                            'tool_calls': [
+                                {
+                                    'id': 'call_1',
+                                    'type': 'function',
+                                    'function': {
+                                        'name': 'read_file',
+                                        'arguments': '{"path": "guide.txt"}',
+                                    },
+                                }
+                            ],
+                        },
+                        'finish_reason': 'tool_calls',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Plugin before-tool guidance consumed.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 7, 'completion_tokens': 2},
+            },
+        ]
+        recorded_payloads: list[dict[str, object]] = []
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            (workspace / 'guide.txt').write_text('plugin before tool\n', encoding='utf-8')
+            plugin_dir = workspace / 'plugins' / 'demo'
+            plugin_dir.mkdir(parents=True)
+            (plugin_dir / 'plugin.json').write_text(
+                json.dumps(
+                    {
+                        'name': 'demo-plugin',
+                        'toolHooks': {
+                            'read_file': {
+                                'beforeTool': 'Validate the path before reading.',
+                            }
+                        },
+                    }
+                ),
+                encoding='utf-8',
+            )
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_recording_urlopen_side_effect(responses, recorded_payloads),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(cwd=workspace),
+                )
+                result = agent.run('Read the file and continue')
+
+        self.assertEqual(result.final_output, 'Plugin before-tool guidance consumed.')
+        self.assertTrue(any(event.get('type') == 'plugin_tool_preflight' for event in result.events))
+        runtime_messages = [
+            message for message in result.transcript
+            if message.get('metadata', {}).get('kind') == 'plugin_tool_runtime'
+        ]
+        self.assertEqual(len(runtime_messages), 1)
+        self.assertIn('Before tool: demo-plugin: Validate the path before reading.', runtime_messages[0].get('content', ''))
+        second_messages = recorded_payloads[1]['messages']
+        assert isinstance(second_messages, list)
+        self.assertTrue(
+            any(
+                isinstance(message, dict)
+                and 'Before tool: demo-plugin: Validate the path before reading.' in str(message.get('content', ''))
+                for message in second_messages
+            )
+        )
+
     def test_runtime_agent_blocks_tool_via_plugin_manifest(self) -> None:
         responses = [
             {
@@ -495,3 +720,317 @@ class QueryEngineRuntimeTests(unittest.TestCase):
         self.assertIn('## Runtime Message Kinds', summary)
         self.assertIn('- plugin_tool_runtime=1', summary)
         self.assertIn('- transcript_messages=', summary)
+
+    def test_query_engine_runtime_stream_emits_runtime_summary_event(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Streaming summary ready.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            }
+        ]
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_urlopen_side_effect(responses),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(cwd=workspace),
+                )
+                engine = QueryEnginePort.from_runtime_agent(agent)
+                events = list(engine.stream_submit_message('Summarize the repo'))
+
+        runtime_summary_events = [
+            event for event in events if event.get('type') == 'runtime_summary'
+        ]
+        self.assertEqual(len(runtime_summary_events), 1)
+        summary_event = runtime_summary_events[0]
+        self.assertIn('runtime_event_counts', summary_event)
+        self.assertIn('transcript_store_entries', summary_event)
+        self.assertIn('transcript_store_compactions', summary_event)
+
+    def test_query_engine_compacts_transcript_store_with_summary_entry(self) -> None:
+        engine = QueryEnginePort.from_workspace()
+        engine.config = QueryEngineConfig(max_turns=6, compact_after_turns=2)
+        engine.submit_message('first prompt')
+        engine.submit_message('second prompt')
+        engine.submit_message('third prompt')
+
+        replay = engine.replay_user_messages()
+        self.assertTrue(any('[transcript-compaction ' in entry for entry in replay))
+        summary = engine.render_summary()
+        self.assertIn('## Transcript Store', summary)
+        self.assertIn('Transcript compactions:', summary)
+
+    def test_query_engine_runtime_summary_tracks_mutation_counts(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Reading the large file first.',
+                            'tool_calls': [
+                                {
+                                    'id': 'call_1',
+                                    'type': 'function',
+                                    'function': {
+                                        'name': 'read_file',
+                                        'arguments': '{"path": "large.txt"}',
+                                    },
+                                }
+                            ],
+                        },
+                        'finish_reason': 'tool_calls',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Mutation summary completed.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 7, 'completion_tokens': 2},
+            },
+        ]
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            (workspace / 'large.txt').write_text(('alpha beta gamma\n' * 400), encoding='utf-8')
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_urlopen_side_effect(responses),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(
+                        cwd=workspace,
+                        auto_snip_threshold_tokens=120,
+                        compact_preserve_messages=0,
+                    ),
+                )
+                engine = QueryEnginePort.from_runtime_agent(agent)
+                turn = engine.submit_message('Read the large file and summarize it')
+                summary = engine.render_summary()
+
+        self.assertEqual(turn.output, 'Mutation summary completed.')
+        self.assertIn('## Runtime Mutations', summary)
+        self.assertIn('- snip_tombstone=1', summary)
+        self.assertIn('- tool_finalize_replace=1', summary)
+        self.assertIn('## Runtime Context Reduction', summary)
+        self.assertIn('- snipped_messages=1', summary)
+
+    def test_query_engine_runtime_summary_tracks_compaction_lineage(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Read the large file first.',
+                            'tool_calls': [
+                                {
+                                    'id': 'call_1',
+                                    'type': 'function',
+                                    'function': {
+                                        'name': 'read_file',
+                                        'arguments': '{"path": "large.txt"}',
+                                    },
+                                }
+                            ],
+                        },
+                        'finish_reason': 'tool_calls',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Compaction lineage summary completed.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 7, 'completion_tokens': 2},
+            },
+        ]
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            (workspace / 'large.txt').write_text(('alpha beta gamma\n' * 400), encoding='utf-8')
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_urlopen_side_effect(responses),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(
+                        cwd=workspace,
+                        auto_compact_threshold_tokens=120,
+                        compact_preserve_messages=0,
+                    ),
+                )
+                engine = QueryEnginePort.from_runtime_agent(agent)
+                turn = engine.submit_message('Read the large file and summarize it')
+                summary = engine.render_summary()
+
+        self.assertEqual(turn.output, 'Compaction lineage summary completed.')
+        self.assertIn('## Runtime Context Reduction', summary)
+        self.assertIn('- compact_boundaries=1', summary)
+        self.assertIn('- compacted_lineages=', summary)
+        self.assertIn('## Runtime Lineage', summary)
+        self.assertIn('- seen_lineages=', summary)
+        self.assertIn('- compacted_lineages=', summary)
+        self.assertIn('- max_source_revision=', summary)
+
+    def test_query_engine_runtime_summary_tracks_assistant_stream_mutations(self) -> None:
+        responses = [
+            [
+                {'choices': [{'delta': {'content': 'Streaming '}, 'finish_reason': None}]},
+                {'choices': [{'delta': {'content': 'works.'}, 'finish_reason': None}]},
+                {
+                    'choices': [{'delta': {}, 'finish_reason': 'stop'}],
+                    'usage': {'prompt_tokens': 14, 'completion_tokens': 5},
+                },
+            ]
+        ]
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_streaming_urlopen_side_effect(responses),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(
+                        cwd=workspace,
+                        stream_model_responses=True,
+                    ),
+                )
+                engine = QueryEnginePort.from_runtime_agent(agent)
+                turn = engine.submit_message('Say streaming works')
+                summary = engine.render_summary()
+
+        self.assertEqual(turn.output, 'Streaming works.')
+        self.assertIn('## Runtime Mutations', summary)
+        self.assertIn('- assistant_delta_append=2', summary)
+        self.assertIn('- assistant_finalize=1', summary)
+
+    def test_query_engine_runtime_summary_tracks_delegate_orchestration(self) -> None:
+        responses = [
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Delegating multiple subtasks.',
+                            'tool_calls': [
+                                {
+                                    'id': 'call_1',
+                                    'type': 'function',
+                                    'function': {
+                                        'name': 'delegate_agent',
+                                        'arguments': json.dumps(
+                                            {
+                                                'subtasks': [
+                                                    {'label': 'scan', 'prompt': 'Scan the project.'},
+                                                    {'label': 'summarize', 'prompt': 'Summarize the project.'},
+                                                ],
+                                                'max_turns': 2,
+                                            }
+                                        ),
+                                    },
+                                }
+                            ],
+                        },
+                        'finish_reason': 'tool_calls',
+                    }
+                ],
+                'usage': {'prompt_tokens': 8, 'completion_tokens': 3},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Child scan result.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 5, 'completion_tokens': 2},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Child summary result.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 6, 'completion_tokens': 2},
+            },
+            {
+                'choices': [
+                    {
+                        'message': {
+                            'role': 'assistant',
+                            'content': 'Parent completed after multi-delegate.',
+                        },
+                        'finish_reason': 'stop',
+                    }
+                ],
+                'usage': {'prompt_tokens': 7, 'completion_tokens': 2},
+            },
+        ]
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            with patch(
+                'src.openai_compat.request.urlopen',
+                side_effect=make_urlopen_side_effect(responses),
+            ):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(
+                        model='Qwen/Qwen3-Coder-30B-A3B-Instruct',
+                        base_url='http://127.0.0.1:8000/v1',
+                    ),
+                    runtime_config=AgentRuntimeConfig(cwd=workspace),
+                )
+                engine = QueryEnginePort.from_runtime_agent(agent)
+                turn = engine.submit_message('Use multiple delegated subtasks')
+                summary = engine.render_summary()
+
+        self.assertEqual(turn.output, 'Parent completed after multi-delegate.')
+        self.assertIn('## Runtime Orchestration', summary)
+        self.assertIn('- group_status:completed=1', summary)
+        self.assertIn('- child_stop:stop=2', summary)