Merge pull request #25 from HarnessLab/update_17_4

Implemented the next missing parity slice around agent configurations.

PARITY_CHECKLIST.md

@@ -114,6 +114,9 @@ Done:
 - [x] Query-engine runtime context-reduction summaries
 - [x] Query-engine runtime lineage summaries
 - [x] Query-engine runtime resumed-child orchestration summaries
+- [x] Filesystem-backed custom agent discovery from `~/.claude/agents` and `./.claude/agents`
+- [x] Active agent override precedence across built-in, user, and project agent definitions
+- [x] Custom agent resolution in the `Agent` tool with model, tool-filter, and initial-prompt support
 
 Missing:
 
@@ -141,6 +144,7 @@ Done:
 - [x] `agent-context` command
 - [x] `agent-context-raw` command
 - [x] `token-budget` command
+- [x] `agents` command
 - [x] Local background session mode
 - [x] Local background session listing (`agent-ps`)
 - [x] Local background session logs (`agent-logs`)
@@ -195,6 +199,7 @@ Done:
 - [x] Local planning guidance section in the Python system prompt
 - [x] Local task guidance section in the Python system prompt
 - [x] Local LSP guidance section in the Python system prompt
+- [x] Local agent-configuration guidance section in the Python system prompt
 
 - [x] Product metadata/branding from `constants/product.ts` — ported to `src/prompt_constants.py`
 - [x] API limits constants from `constants/apiLimits.ts` — ported to `src/prompt_constants.py`
@@ -312,7 +317,7 @@ Done (53 slash command names in 37 specs):
 Missing npm slash commands (from `src/commands/` — 80+ commands total):
 
 - [x] `/add-dir` — Add a new working directory
-- [ ] `/agents` — Manage agent configurations
+- [x] `/agents` — Inspect local agent configurations and show active definitions
 - [x] `/branch` — Create a branch of the current conversation
 - [ ] `/bridge` — Connect for remote-control sessions
 - [ ] `/btw` — Quick side question without interrupting main conversation
@@ -361,6 +366,7 @@ Missing npm slash commands (from `src/commands/` — 80+ commands total):
 - [ ] Feature-gated: `/buddy`, `/fork`, `/peers`, `/proactive`, `/torch`, `/workflows` (full), etc.
 - [ ] Internal: `/backfill-sessions`, `/break-cache`, `/bughunter`, `/commit-push-pr`, `/init-verifiers`, `/mock-limits`, `/version`, `/ultraplan`, `/autofix-pr`, etc.
 - [x] `/commit` — Create a git commit (prompt-type with injected git context)
+- [ ] Full `/agents` parity for create/edit/delete flows and multi-source management UI
 
 ## 6. Built-in Tools
 

README.md

@@ -31,6 +31,7 @@
 | 🆕 | **Plugin Runtime** | Full manifest-based plugin system — hooks, tool aliases, virtual tools, tool blocking |
 | 🆕 | **Nested Agent Delegation** | Delegate subtasks to child agents with dependency-aware topological batching |
 | 🆕 | **Agent Manager** | Lineage tracking, group membership, batch summaries for nested agents |
+| 🆕 | **Custom Agent Profiles** | Discover local markdown-defined agents from `~/.claude/agents` and `./.claude/agents` and use them through the `Agent` tool |
 | 🆕 | **Cost Tracking & Budgets** | Token budgets, cost budgets, tool-call limits, model-call limits, session-turn limits |
 | 🆕 | **Structured Output** | JSON schema response mode with `--response-schema-file` |
 | 🆕 | **Context Compaction** | Auto-snip, auto-compact, and reactive compaction on prompt-too-long errors |
@@ -87,6 +88,7 @@ Built on the public porting workspace from [instructkr/claw-code](https://github
 | 🧰 **Core Tools** | File read / write / edit, glob search, grep search, shell execution |
 | 🔌 **Plugin Runtime** | Manifest-based plugins with hooks, aliases, virtual tools, and tool blocking |
 | 🪆 **Nested Delegation** | Delegate subtasks to child agents with dependency-aware topological batching |
+| 🧩 **Custom Agents** | Load local agent profiles from `~/.claude/agents` and `./.claude/agents`, inspect them via `/agents`, and delegate with `subagent_type` |
 | 📡 **Streaming** | Token-by-token streaming output with `--stream` |
 | 💬 **Slash Commands** | Local commands for context, config, account, search, MCP, remote, tasks, plan, hooks, and model control |
 | 🌐 **Remote Runtime** | Manifest-backed remote profiles with local `remote-mode`, `ssh-mode`, `teleport-mode`, and connect/disconnect state |
@@ -134,7 +136,7 @@ Built on the public porting workspace from [instructkr/claw-code](https://github
 - [x] Ollama, LiteLLM Proxy, and OpenRouter backends
 - [x] Core tools: `list_dir`, `read_file`, `write_file`, `edit_file`, `glob_search`, `grep_search`, `bash`
 - [x] Context building and `/context`-style usage reporting
-- [x] Slash commands: `/help`, `/context`, `/context-raw`, `/prompt`, `/permissions`, `/model`, `/tools`, `/memory`, `/status`, `/clear`
+- [x] Slash commands: `/help`, `/context`, `/context-raw`, `/token-budget`, `/prompt`, `/permissions`, `/model`, `/tools`, `/agents`, `/memory`, `/status`, `/clear`
 - [x] Session persistence and `agent-resume` flow
 - [x] Permission system (read-only, write, shell, unsafe tiers)
 - [x] Streaming token-by-token assistant output
@@ -149,6 +151,7 @@ Built on the public porting workspace from [instructkr/claw-code](https://github
 - [x] File history journaling with snapshot IDs and replay summaries
 - [x] Nested agent delegation with dependency-aware topological batching
 - [x] Agent manager with lineage tracking and group membership
+- [x] Filesystem-backed custom agent profiles with built-in/user/project precedence
 - [x] Local daemon-style background command family
 - [x] Local background session workflows: `agent-bg`, `agent-ps`, `agent-logs`, `agent-attach`, `agent-kill`
 - [x] Local remote runtime: manifest discovery, profile listing, connect/disconnect persistence, and CLI/slash flows
@@ -205,6 +208,7 @@ claw-code/
 │   ├── agent_runtime.py          # Core agent loop (LocalCodingAgent)
 │   ├── agent_tools.py            # Tool definitions & execution engine
 │   ├── agent_prompting.py        # System prompt assembly
+│   ├── agent_registry.py         # Built-in + filesystem-backed custom agent discovery
 │   ├── agent_context.py          # Context building & CLAUDE.md discovery
 │   ├── agent_context_usage.py    # Context usage estimation & reporting
 │   ├── agent_session.py          # Session state management
@@ -446,6 +450,7 @@ python3 -m src.main agent \
 | `agent-context` | Show estimated context usage |
 | `agent-context-raw` | Show the raw context snapshot |
 | `token-budget` | Show prompt-window budget, reserves, and soft/hard input limits |
+| `agents [agent_type]` | List active local agent definitions or show one agent profile |
 | `agent-resume <id> <prompt>` | Resume a saved session |
 
 ### Runtime Utility Commands
@@ -545,6 +550,7 @@ These are handled **locally** before the model loop:
 | `/permissions` | — | Show active tool permission mode |
 | `/model` | — | Show or update the active model |
 | `/tools` | — | List registered tools with permission status |
+| `/agents` | — | List active local agent definitions or show one profile |
 | `/memory` | — | Show loaded CLAUDE.md memory bundle |
 | `/status` | `/session` | Show runtime/session status summary |
 | `/clear` | — | Clear ephemeral runtime state |
@@ -554,9 +560,42 @@ python3 -m src.main agent "/help"
 python3 -m src.main agent "/context" --cwd .
 python3 -m src.main agent "/token-budget" --cwd .
 python3 -m src.main agent "/tools" --cwd .
+python3 -m src.main agent "/agents" --cwd .
 python3 -m src.main agent "/status" --cwd .
 ```
 
+### Custom Agent Definitions
+
+Custom agent profiles can live in either of these directories:
+
+- `./.claude/agents/*.md`
+- `~/.claude/agents/*.md`
+
+Project agents override user agents, and user agents override built-ins when the `agent_type` matches.
+
+Example agent file:
+
+```md
+---
+name: reviewer
+description: "Review implementation changes carefully."
+tools: read_file, grep_search
+model: Qwen/Qwen3-Coder-30B-A3B-Instruct
+initialPrompt: Start by identifying the highest-risk files.
+---
+
+Inspect code changes and summarize correctness risks, regressions, and missing tests.
+```
+
+Inspect the loaded profiles:
+
+```bash
+python3 -m src.main agents --cwd .
+python3 -m src.main agents reviewer --cwd .
+python3 -m src.main agent "/agents" --cwd .
+python3 -m src.main agent "/agents show reviewer" --cwd .
+```
+
 ### Utility Commands
 
 ```bash

TESTING_GUIDE.md

@@ -580,6 +580,24 @@ EOF
 mkdir -p ./test_cases_tasks
 ```
 
+### 4.9 Custom agent definitions
+
+```bash
+mkdir -p ./test_cases_agents/.claude/agents
+
+cat > ./test_cases_agents/.claude/agents/reviewer.md <<'EOF'
+---
+name: reviewer
+description: "Review implementation changes carefully."
+tools: read_file, grep_search
+model: Qwen/Qwen3-Coder-30B-A3B-Instruct
+initialPrompt: Start by identifying the highest-risk files.
+---
+
+Inspect code changes and summarize correctness risks, regressions, and missing tests.
+EOF
+```
+
 ## 5. Slash Command Matrix
 
 Slash commands are handled locally before the model loop.
@@ -601,6 +619,8 @@ python3 -m src.main agent "/permissions" --cwd ./test_cases
 python3 -m src.main agent "/model" --cwd ./test_cases
 python3 -m src.main agent "/model demo-model" --cwd ./test_cases
 python3 -m src.main agent "/tools" --cwd ./test_cases
+python3 -m src.main agent "/agents" --cwd ./test_cases_agents
+python3 -m src.main agent "/agents show reviewer" --cwd ./test_cases_agents
 python3 -m src.main agent "/memory" --cwd ./test_cases
 python3 -m src.main agent "/status" --cwd ./test_cases
 python3 -m src.main agent "/session" --cwd ./test_cases
@@ -678,6 +698,8 @@ python3 -m src.main agent-prompt --cwd ./test_cases
 python3 -m src.main agent-context --cwd ./test_cases
 python3 -m src.main agent-context-raw --cwd ./test_cases
 python3 -m src.main token-budget --cwd ./test_cases
+python3 -m src.main agents --cwd ./test_cases_agents
+python3 -m src.main agents reviewer --cwd ./test_cases_agents
 ```
 
 ### 6.2 Extra working directories and `CLAUDE.md` toggle

src/__init__.py

@@ -11,6 +11,14 @@ from .agent_context import (
     set_system_prompt_injection,
 )
 from .agent_manager import AgentManager
+from .agent_registry import (
+    AgentLoadError,
+    AgentRegistrySnapshot,
+    find_agent_definition,
+    load_agent_registry,
+    render_agent_detail,
+    render_agents_report,
+)
 from .agent_runtime import LocalCodingAgent
 from .agent_session import AgentMessage, AgentSessionState
 from .agent_tools import build_tool_context, default_tool_registry, execute_tool
@@ -42,7 +50,9 @@ from .tools import PORTED_TOOLS, build_tool_backlog
 __all__ = [
     'AgentContextSnapshot',
     'AgentManager',
+    'AgentLoadError',
     'AgentPermissions',
+    'AgentRegistrySnapshot',
     'AgentRunResult',
     'AgentRuntimeConfig',
     'AccountProfile',
@@ -114,10 +124,14 @@ __all__ = [
     'describe_token_counter',
     'estimate_chat_overhead',
     'execute_tool',
+    'find_agent_definition',
     'format_token_budget',
     'get_system_context',
     'get_user_context',
+    'load_agent_registry',
     'load_session',
+    'render_agent_detail',
+    'render_agents_report',
     'run_parity_audit',
     'save_session',
     'set_system_prompt_injection',

src/agent_prompting.py

@@ -6,6 +6,7 @@ from pathlib import Path
 from .agent_context import build_context_snapshot
 from .agent_tools import AgentTool
 from .agent_types import AgentRuntimeConfig, ModelConfig
+from .builtin_agents import AgentDefinition, format_agent_listing
 
 SYSTEM_PROMPT_DYNAMIC_BOUNDARY = '__SYSTEM_PROMPT_DYNAMIC_BOUNDARY__'
 
@@ -76,6 +77,7 @@ def build_system_prompt_parts(
     prompt_context: PromptContext,
     runtime_config: AgentRuntimeConfig,
     tools: dict[str, AgentTool],
+    available_agents: tuple[AgentDefinition, ...] = (),
     custom_system_prompt: str | None = None,
     append_system_prompt: str | None = None,
     override_system_prompt: str | None = None,
@@ -90,6 +92,7 @@ def build_system_prompt_parts(
         get_doing_tasks_section(),
         get_actions_section(),
         get_using_your_tools_section(enabled_tool_names),
+        get_agent_guidance_section(enabled_tool_names, available_agents),
         get_plugin_guidance_section(prompt_context),
         get_mcp_guidance_section(prompt_context),
         get_remote_guidance_section(prompt_context),
@@ -204,6 +207,26 @@ def get_tone_and_style_section() -> str:
     return '\n'.join(['# Tone and style', *prepend_bullets(items)])
 
 
+def get_agent_guidance_section(
+    enabled_tool_names: set[str],
+    available_agents: tuple[AgentDefinition, ...],
+) -> str:
+    if 'Agent' not in enabled_tool_names and 'delegate_agent' not in enabled_tool_names:
+        return ''
+    items: list[str] = [
+        'Use the Agent tool when a bounded subtask can be delegated to a specialized agent profile.',
+        'Pick a specific subagent_type when one of the available agent profiles clearly fits the task.',
+    ]
+    if not available_agents:
+        return '\n'.join(['# Agents', *prepend_bullets(items)])
+    rendered_agents = list(format_agent_listing(available_agents[:20]).splitlines())
+    items.append('Available agent types:')
+    items.append(rendered_agents)
+    if len(available_agents) > 20:
+        items.append(f'... plus {len(available_agents) - 20} more agent definitions.')
+    return '\n'.join(['# Agents', *prepend_bullets(items)])
+
+
 def get_plugin_guidance_section(prompt_context: PromptContext) -> str:
     plugin_cache = prompt_context.user_context.get('pluginCache')
     plugin_runtime = prompt_context.user_context.get('pluginRuntime')

src/agent_registry.py

@@ -0,0 +1,395 @@
+from __future__ import annotations
+
+import ast
+import csv
+import re
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+from .builtin_agents import AgentDefinition, describe_agent_tools, get_builtin_agents
+
+_FRONTMATTER_RE = re.compile(r'^---\n(.*?)\n---\n?(.*)$', re.DOTALL)
+_AGENTS_DIR = Path('.claude') / 'agents'
+_SOURCE_ORDER = {
+    'built-in': 0,
+    'userSettings': 1,
+    'projectSettings': 2,
+}
+
+
+@dataclass(frozen=True)
+class AgentLoadError:
+    path: str
+    source: str
+    error: str
+
+
+@dataclass(frozen=True)
+class AgentRegistrySnapshot:
+    all_agents: tuple[AgentDefinition, ...]
+    active_agents: tuple[AgentDefinition, ...]
+    shadowed_agents: tuple[AgentDefinition, ...]
+    failed_files: tuple[AgentLoadError, ...]
+
+
+def load_agent_registry(cwd: Path) -> AgentRegistrySnapshot:
+    builtin_agents = tuple(get_builtin_agents())
+    loaded_agents: list[AgentDefinition] = list(builtin_agents)
+    failed_files: list[AgentLoadError] = []
+    for source, directory in iter_agent_directories(cwd):
+        if not directory.is_dir():
+            continue
+        for path in sorted(directory.glob('*.md')):
+            try:
+                loaded_agents.append(load_agent_markdown(path, source=source))
+            except (OSError, ValueError) as exc:
+                failed_files.append(
+                    AgentLoadError(
+                        path=str(path),
+                        source=source,
+                        error=str(exc),
+                    )
+                )
+    active_agents, shadowed_agents = resolve_active_agents(tuple(loaded_agents))
+    return AgentRegistrySnapshot(
+        all_agents=tuple(loaded_agents),
+        active_agents=active_agents,
+        shadowed_agents=shadowed_agents,
+        failed_files=tuple(failed_files),
+    )
+
+
+def iter_agent_directories(cwd: Path) -> tuple[tuple[str, Path], ...]:
+    return (
+        ('userSettings', Path.home() / _AGENTS_DIR),
+        ('projectSettings', cwd / _AGENTS_DIR),
+    )
+
+
+def find_agent_definition(
+    cwd: Path,
+    agent_type: str,
+    *,
+    active_only: bool = True,
+) -> AgentDefinition | None:
+    snapshot = load_agent_registry(cwd)
+    pool = snapshot.active_agents if active_only else snapshot.all_agents
+    for agent in pool:
+        if agent.agent_type == agent_type:
+            return agent
+    return None
+
+
+def resolve_active_agents(
+    all_agents: tuple[AgentDefinition, ...],
+) -> tuple[tuple[AgentDefinition, ...], tuple[AgentDefinition, ...]]:
+    active_by_name: dict[str, AgentDefinition] = {}
+    for agent in all_agents:
+        current = active_by_name.get(agent.agent_type)
+        if current is None or _source_rank(agent.source) >= _source_rank(current.source):
+            active_by_name[agent.agent_type] = agent
+
+    active_agents = tuple(
+        sorted(
+            active_by_name.values(),
+            key=lambda agent: (_source_rank(agent.source), agent.agent_type.lower()),
+        )
+    )
+    shadowed_agents = tuple(
+        sorted(
+            (
+                agent
+                for agent in all_agents
+                if active_by_name.get(agent.agent_type) is not agent
+            ),
+            key=lambda agent: (agent.agent_type.lower(), _source_rank(agent.source)),
+        )
+    )
+    return active_agents, shadowed_agents
+
+
+def load_agent_markdown(path: Path, *, source: str) -> AgentDefinition:
+    text = path.read_text(encoding='utf-8')
+    metadata, body = _split_frontmatter(text)
+    agent_type = str(metadata.get('name') or path.stem).strip()
+    if not agent_type:
+        raise ValueError(f'Agent file {path} is missing a name')
+    when_to_use = str(
+        metadata.get('description')
+        or metadata.get('whenToUse')
+        or metadata.get('when_to_use')
+        or ''
+    ).strip()
+    if not when_to_use:
+        raise ValueError(f'Agent file {path} is missing a description')
+    system_prompt = body.strip()
+    if not system_prompt:
+        system_prompt = str(metadata.get('prompt') or '').strip()
+    if not system_prompt:
+        raise ValueError(f'Agent file {path} is missing a system prompt body')
+    tools = _parse_tool_list(metadata.get('tools'))
+    disallowed_tools = tuple(_coerce_string_list(metadata.get('disallowedTools')))
+    return AgentDefinition(
+        agent_type=agent_type,
+        when_to_use=when_to_use,
+        system_prompt=system_prompt,
+        model=_coerce_optional_string(metadata.get('model')),
+        tools=tools,
+        disallowed_tools=disallowed_tools,
+        color=_coerce_optional_string(metadata.get('color')),
+        background=_coerce_bool(metadata.get('background')),
+        one_shot=_coerce_bool(metadata.get('oneShot')),
+        omit_claude_md=_coerce_bool(metadata.get('omitClaudeMd')),
+        permission_mode=_coerce_optional_string(
+            metadata.get('permissionMode') or metadata.get('permission_mode')
+        ),
+        max_turns=_coerce_optional_int(metadata.get('maxTurns')),
+        critical_system_reminder=_coerce_optional_string(
+            metadata.get('criticalSystemReminder')
+            or metadata.get('criticalSystemReminder_EXPERIMENTAL')
+        ),
+        source=source,
+        filename=path.stem,
+        base_dir=str(path.parent),
+        skills=tuple(_coerce_string_list(metadata.get('skills'))),
+        memory=_coerce_optional_string(metadata.get('memory')),
+        effort=_coerce_effort(metadata.get('effort')),
+        initial_prompt=_coerce_optional_string(
+            metadata.get('initialPrompt') or metadata.get('initial_prompt')
+        ),
+        isolation=_coerce_optional_string(metadata.get('isolation')),
+        hook_names=tuple(_coerce_hook_names(metadata.get('hooks'))),
+    )
+
+
+def render_agents_report(
+    snapshot: AgentRegistrySnapshot,
+    *,
+    cwd: Path,
+    show_all: bool = False,
+) -> str:
+    lines = [
+        '# Agents',
+        '',
+        f'- Active agent types: {len(snapshot.active_agents)}',
+        f'- All discovered definitions: {len(snapshot.all_agents)}',
+        f'- Shadowed definitions: {len(snapshot.shadowed_agents)}',
+        f'- Failed files: {len(snapshot.failed_files)}',
+        '- Source precedence: built-in < userSettings < projectSettings',
+        '',
+        '## Sources',
+        f'- built-in: {_count_source(snapshot.all_agents, "built-in")}',
+    ]
+    for source, directory in iter_agent_directories(cwd):
+        lines.append(
+            f'- {source}: {_count_source(snapshot.all_agents, source)} ({directory})'
+        )
+    lines.extend(['', '## All Agents' if show_all else '## Active Agents'])
+    visible_agents = snapshot.all_agents if show_all else snapshot.active_agents
+    if not visible_agents:
+        lines.append('No agent definitions were discovered.')
+    else:
+        for agent in visible_agents:
+            lines.append(
+                f'- {agent.agent_type} [{agent.source}]'
+                f' ; tools={describe_agent_tools(agent)}'
+                f' ; model={agent.model or "inherit"}'
+            )
+    if snapshot.shadowed_agents:
+        lines.extend(['', '## Shadowed Agents'])
+        for agent in snapshot.shadowed_agents:
+            winner = _winner_for(snapshot, agent.agent_type)
+            winner_desc = winner.source if winner is not None else 'unknown'
+            lines.append(
+                f'- {agent.agent_type} [{agent.source}] shadowed by {winner_desc}'
+            )
+    if snapshot.failed_files:
+        lines.extend(['', '## Failed Files'])
+        for item in snapshot.failed_files:
+            lines.append(f'- {item.path}: {item.error}')
+    return '\n'.join(lines)
+
+
+def render_agent_detail(snapshot: AgentRegistrySnapshot, agent_type: str) -> str:
+    agent = next(
+        (candidate for candidate in snapshot.active_agents if candidate.agent_type == agent_type),
+        None,
+    )
+    if agent is None:
+        agent = next(
+            (candidate for candidate in snapshot.all_agents if candidate.agent_type == agent_type),
+            None,
+        )
+    if agent is None:
+        return f'# Agent\n\nUnknown agent: {agent_type}'
+
+    lines = [
+        f'# Agent: {agent.agent_type}',
+        '',
+        f'- Source: {agent.source}',
+        f'- Model: {agent.model or "inherit"}',
+        f'- Tools: {describe_agent_tools(agent)}',
+        f'- Permission mode: {agent.permission_mode or "(default)"}',
+        f'- Max turns: {agent.max_turns if agent.max_turns is not None else "(default)"}',
+        f'- Background: {agent.background}',
+        f'- One-shot: {agent.one_shot}',
+        f'- Omit CLAUDE.md: {agent.omit_claude_md}',
+    ]
+    if agent.base_dir:
+        lines.append(f'- Base directory: {agent.base_dir}')
+    if agent.filename:
+        lines.append(f'- Definition file: {Path(agent.base_dir or ".") / (agent.filename + ".md")}')
+    if agent.color:
+        lines.append(f'- Color: {agent.color}')
+    if agent.memory:
+        lines.append(f'- Memory: {agent.memory}')
+    if agent.effort is not None:
+        lines.append(f'- Effort: {agent.effort}')
+    if agent.isolation:
+        lines.append(f'- Isolation: {agent.isolation}')
+    if agent.skills:
+        lines.append(f'- Skills: {", ".join(agent.skills)}')
+    if agent.hook_names:
+        lines.append(f'- Hooks: {", ".join(agent.hook_names)}')
+    if agent.initial_prompt:
+        lines.extend(['', '## Initial Prompt', agent.initial_prompt])
+    lines.extend(['', '## When To Use', agent.when_to_use, '', '## System Prompt', agent.system_prompt])
+    return '\n'.join(lines)
+
+
+def _split_frontmatter(text: str) -> tuple[dict[str, Any], str]:
+    normalized = text.replace('\r\n', '\n')
+    match = _FRONTMATTER_RE.match(normalized)
+    if match is None:
+        return {}, normalized
+    return _parse_frontmatter(match.group(1)), match.group(2)
+
+
+def _parse_frontmatter(block: str) -> dict[str, Any]:
+    metadata: dict[str, Any] = {}
+    for raw_line in block.splitlines():
+        line = raw_line.strip()
+        if not line or line.startswith('#'):
+            continue
+        if ':' not in line:
+            continue
+        key, raw_value = line.split(':', 1)
+        metadata[key.strip()] = _parse_frontmatter_value(raw_value.strip())
+    return metadata
+
+
+def _parse_frontmatter_value(value: str) -> Any:
+    if not value:
+        return ''
+    if value.startswith(('"', "'")) and value.endswith(('"', "'")):
+        try:
+            return ast.literal_eval(value)
+        except (ValueError, SyntaxError):
+            return value[1:-1]
+    lowered = value.lower()
+    if lowered == 'true':
+        return True
+    if lowered == 'false':
+        return False
+    if re.fullmatch(r'-?\d+', value):
+        return int(value)
+    if value.startswith('[') and value.endswith(']'):
+        inner = value[1:-1].strip()
+        if not inner:
+            return []
+        reader = csv.reader([inner], skipinitialspace=True)
+        return [item.strip().strip('"').strip("'") for item in next(reader)]
+    return value
+
+
+def _parse_tool_list(value: Any) -> tuple[str, ...] | None:
+    if value is None or value == '':
+        return None
+    tools = tuple(_coerce_string_list(value))
+    if not tools:
+        return None
+    if tools == ('*',):
+        return None
+    return tools
+
+
+def _coerce_string_list(value: Any) -> list[str]:
+    if value is None:
+        return []
+    if isinstance(value, str):
+        stripped = value.strip()
+        if not stripped:
+            return []
+        if stripped.startswith('[') and stripped.endswith(']'):
+            parsed = _parse_frontmatter_value(stripped)
+            if isinstance(parsed, list):
+                return [str(item).strip() for item in parsed if str(item).strip()]
+        return [item.strip() for item in stripped.split(',') if item.strip()]
+    if isinstance(value, (list, tuple)):
+        return [str(item).strip() for item in value if str(item).strip()]
+    return [str(value).strip()]
+
+
+def _coerce_optional_string(value: Any) -> str | None:
+    if value is None:
+        return None
+    text = str(value).strip()
+    return text or None
+
+
+def _coerce_optional_int(value: Any) -> int | None:
+    if value is None or value == '':
+        return None
+    if isinstance(value, bool):
+        return None
+    if isinstance(value, int):
+        return value
+    try:
+        return int(str(value).strip())
+    except ValueError:
+        return None
+
+
+def _coerce_bool(value: Any) -> bool:
+    if isinstance(value, bool):
+        return value
+    if isinstance(value, str):
+        return value.strip().lower() in {'1', 'true', 'yes', 'on'}
+    return bool(value)
+
+
+def _coerce_effort(value: Any) -> str | int | None:
+    if value is None or value == '':
+        return None
+    if isinstance(value, int):
+        return value
+    text = str(value).strip()
+    if not text:
+        return None
+    if text.isdigit():
+        return int(text)
+    return text
+
+
+def _coerce_hook_names(value: Any) -> list[str]:
+    if value is None:
+        return []
+    if isinstance(value, dict):
+        return [str(item).strip() for item in value if str(item).strip()]
+    return _coerce_string_list(value)
+
+
+def _count_source(all_agents: tuple[AgentDefinition, ...], source: str) -> int:
+    return sum(1 for agent in all_agents if agent.source == source)
+
+
+def _winner_for(snapshot: AgentRegistrySnapshot, agent_type: str) -> AgentDefinition | None:
+    for agent in snapshot.active_agents:
+        if agent.agent_type == agent_type:
+            return agent
+    return None
+
+
+def _source_rank(source: str) -> int:
+    return _SOURCE_ORDER.get(source, -1)

src/agent_runtime.py

@@ -14,6 +14,12 @@ from .agent_context import render_context_report as render_agent_context_report
 from .agent_context_usage import collect_context_usage, estimate_tokens, format_context_usage
 from .compact import compact_conversation
 from .ask_user_runtime import AskUserRuntime
+from .agent_registry import (
+    find_agent_definition,
+    load_agent_registry,
+    render_agent_detail,
+    render_agents_report,
+)
 from .config_runtime import ConfigRuntime
 from .hook_policy import HookPolicyRuntime
 from .lsp_runtime import LSPRuntime
@@ -67,9 +73,6 @@ from .session_store import (
 from .token_budget import calculate_token_budget, format_token_budget
 from .builtin_agents import (
     AgentDefinition,
-    get_agent_definition,
-    get_builtin_agents,
-    format_agent_listing,
     ALL_AGENT_DISALLOWED_TOOLS,
     GENERAL_PURPOSE_AGENT,
 )
@@ -256,11 +259,18 @@ class LocalCodingAgent:
             prompt_context=prompt_context,
             runtime_config=self.runtime_config,
             tools=self.tool_registry,
+            available_agents=self.available_agents(),
             custom_system_prompt=self.custom_system_prompt,
             append_system_prompt=self.append_system_prompt,
             override_system_prompt=self.override_system_prompt,
         )
 
+    def load_agent_registry(self):
+        return load_agent_registry(self.runtime_config.cwd)
+
+    def available_agents(self) -> tuple[AgentDefinition, ...]:
+        return self.load_agent_registry().active_agents
+
     def build_session(
         self,
         user_prompt: str | None = None,
@@ -2130,7 +2140,7 @@ class LocalCodingAgent:
         """Resolve the agent definition from subagent_type or default to general-purpose."""
         subagent_type = arguments.get('subagent_type')
         if isinstance(subagent_type, str) and subagent_type:
-            agent_def = get_agent_definition(subagent_type)
+            agent_def = find_agent_definition(self.runtime_config.cwd, subagent_type)
             if agent_def is not None:
                 return agent_def
         return GENERAL_PURPOSE_AGENT
@@ -2145,17 +2155,12 @@ class LocalCodingAgent:
         agent_model = agent_def.model
 
         # Explicit model param in arguments takes priority
-        if isinstance(model_override, str) and model_override in ('sonnet', 'opus', 'haiku'):
+        if isinstance(model_override, str) and model_override.strip():
-            # Map friendly names to actual model identifiers if a mapping is available,
+            return replace(self.model_config, model=model_override.strip())
-            # otherwise use the parent's model config as base
-            return self.model_config
 
         # Agent definition model
         if agent_model and agent_model != 'inherit':
-            # Agent definitions may specify 'haiku', 'sonnet', 'opus'
+            return replace(self.model_config, model=agent_model)
-            # For now, inherit the parent's model config (model routing would
-            # require a model registry which is out of scope)
-            return self.model_config
 
         return self.model_config
 
@@ -2394,7 +2399,12 @@ class LocalCodingAgent:
                         child_agent.managed_agent_id,
                         child_index=index,
                     )
+                resume_session_id = subtask.get('resume_session_id')
                 child_prompt = str(subtask['prompt'])
+                if agent_def.initial_prompt and not (
+                    isinstance(resume_session_id, str) and resume_session_id
+                ):
+                    child_prompt = f'{agent_def.initial_prompt.strip()}\n\n{child_prompt}'.strip()
                 if delegate_preflight_messages:
                     child_prompt = self._prepend_plugin_delegate_context(
                         child_prompt,
@@ -2402,7 +2412,6 @@ class LocalCodingAgent:
                     )
                 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:
@@ -3397,6 +3406,18 @@ class LocalCodingAgent:
             lines.append(f'- `{tool.name}`: {tool.description} [{state}]')
         return '\n'.join(lines)
 
+    def render_agents_report(self, *, show_all: bool = False) -> str:
+        snapshot = self.load_agent_registry()
+        return render_agents_report(
+            snapshot,
+            cwd=self.runtime_config.cwd,
+            show_all=show_all,
+        )
+
+    def render_agent_detail_report(self, agent_type: str) -> str:
+        snapshot = self.load_agent_registry()
+        return render_agent_detail(snapshot, agent_type)
+
     def render_memory_report(self) -> str:
         prompt_context = self.build_prompt_context()
         claude_md = prompt_context.user_context.get('claudeMd')

src/agent_slash_commands.py

@@ -289,6 +289,11 @@ def get_slash_command_specs() -> tuple[SlashCommandSpec, ...]:
             description='List the registered tools and whether the current permissions allow them.',
             handler=_handle_tools,
         ),
+        SlashCommandSpec(
+            names=('agents',),
+            description='List active local agent configurations or show one agent definition by name.',
+            handler=_handle_agents,
+        ),
         SlashCommandSpec(
             names=('memory',),
             description='Show the currently loaded CLAUDE.md memory bundle and discovered files.',
@@ -798,6 +803,20 @@ def _handle_tools(agent: 'LocalCodingAgent', _args: str, input_text: str) -> Sla
     return _local_result(input_text, agent.render_tools_report())
 
 
+def _handle_agents(agent: 'LocalCodingAgent', args: str, input_text: str) -> SlashCommandResult:
+    trimmed = args.strip()
+    if not trimmed or trimmed in {'active', 'list'}:
+        return _local_result(input_text, agent.render_agents_report())
+    if trimmed == 'all':
+        return _local_result(input_text, agent.render_agents_report(show_all=True))
+    if trimmed.startswith('show '):
+        agent_type = trimmed[5:].strip()
+        if not agent_type:
+            return _local_result(input_text, 'Usage: /agents [all|active|show <agent-type>]')
+        return _local_result(input_text, agent.render_agent_detail_report(agent_type))
+    return _local_result(input_text, agent.render_agent_detail_report(trimmed))
+
+
 def _handle_memory(agent: 'LocalCodingAgent', _args: str, input_text: str) -> SlashCommandResult:
     return _local_result(input_text, agent.render_memory_report())
 

src/builtin_agents.py

@@ -34,6 +34,14 @@ class AgentDefinition:
     max_turns: int | None = None
     critical_system_reminder: str | None = None
     source: str = 'built-in'
+    filename: str | None = None
+    base_dir: str | None = None
+    skills: tuple[str, ...] = ()
+    memory: str | None = None
+    effort: str | int | None = None
+    initial_prompt: str | None = None
+    isolation: str | None = None
+    hook_names: tuple[str, ...] = ()
 
 
 # ---------------------------------------------------------------------------
@@ -411,12 +419,12 @@ def format_agent_listing(agents: tuple[AgentDefinition, ...] | None = None) -> s
         agents = _BUILTIN_AGENTS
     lines: list[str] = []
     for agent in agents:
-        tools_desc = _describe_tools(agent)
+        tools_desc = describe_agent_tools(agent)
         lines.append(f'- {agent.agent_type}: {agent.when_to_use} (Tools: {tools_desc})')
     return '\n'.join(lines)
 
 
-def _describe_tools(agent: AgentDefinition) -> str:
+def describe_agent_tools(agent: AgentDefinition) -> str:
     """Describe the tool access for an agent definition."""
     if agent.tools is not None:
         return ', '.join(agent.tools) if agent.tools else 'none'

src/main.py

@@ -874,6 +874,11 @@ def build_parser() -> argparse.ArgumentParser:
 
     token_budget_parser = subparsers.add_parser('token-budget', help='render the current token budget and prompt-length limits')
     _add_agent_common_args(token_budget_parser, include_backend=False)
+
+    agents_parser = subparsers.add_parser('agents', help='list active local agent configurations or show one agent definition')
+    agents_parser.add_argument('agent_type', nargs='?')
+    agents_parser.add_argument('--all', action='store_true')
+    _add_agent_common_args(agents_parser, include_backend=False)
     return parser
 
 
@@ -1507,6 +1512,13 @@ def main(argv: list[str] | None = None) -> int:
         agent.last_session = agent.build_session()
         print(agent.render_token_budget_report())
         return 0
+    if args.command == 'agents':
+        agent = _build_agent(args)
+        if args.agent_type:
+            print(agent.render_agent_detail_report(args.agent_type))
+        else:
+            print(agent.render_agents_report(show_all=bool(args.all)))
+        return 0
 
     parser.error(f'unknown command: {args.command}')
     return 2

tests/test_agent_registry.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import os
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+from src.agent_registry import load_agent_registry, render_agent_detail, render_agents_report
+
+
+def _write_agent(path: Path, *, name: str, description: str, body: str, extra: str = '') -> None:
+    payload = (
+        '---\n'
+        f'name: {name}\n'
+        f'description: "{description}"\n'
+        f'{extra}'
+        '---\n\n'
+        f'{body}\n'
+    )
+    path.write_text(payload, encoding='utf-8')
+
+
+class AgentRegistryTests(unittest.TestCase):
+    def test_project_agent_overrides_built_in_agent(self) -> None:
+        with tempfile.TemporaryDirectory() as home_dir, tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            agents_dir = workspace / '.claude' / 'agents'
+            agents_dir.mkdir(parents=True)
+            _write_agent(
+                agents_dir / 'Explore.md',
+                name='Explore',
+                description='Project-specific explore agent.',
+                body='Search this repository carefully before answering.',
+                extra=(
+                    'tools: read_file, grep_search\n'
+                    'model: child-model\n'
+                    'initialPrompt: Begin with rg-style discovery.\n'
+                ),
+            )
+
+            with patch.dict(os.environ, {'HOME': home_dir}):
+                snapshot = load_agent_registry(workspace)
+
+            active = {agent.agent_type: agent for agent in snapshot.active_agents}
+            self.assertIn('Explore', active)
+            self.assertEqual(active['Explore'].source, 'projectSettings')
+            self.assertEqual(active['Explore'].model, 'child-model')
+            self.assertEqual(active['Explore'].tools, ('read_file', 'grep_search'))
+            self.assertEqual(active['Explore'].initial_prompt, 'Begin with rg-style discovery.')
+
+            report = render_agents_report(snapshot, cwd=workspace)
+            self.assertIn('Explore [projectSettings]', report)
+            self.assertIn('Shadowed Agents', report)
+
+            detail = render_agent_detail(snapshot, 'Explore')
+            self.assertIn('Project-specific explore agent.', detail)
+            self.assertIn('Begin with rg-style discovery.', detail)
+            self.assertIn('Search this repository carefully before answering.', detail)
+
+    def test_invalid_agent_file_is_reported(self) -> None:
+        with tempfile.TemporaryDirectory() as home_dir, tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            agents_dir = workspace / '.claude' / 'agents'
+            agents_dir.mkdir(parents=True)
+            (agents_dir / 'broken.md').write_text(
+                '---\nname: broken\n---\n',
+                encoding='utf-8',
+            )
+
+            with patch.dict(os.environ, {'HOME': home_dir}):
+                snapshot = load_agent_registry(workspace)
+
+            self.assertEqual(len(snapshot.failed_files), 1)
+            self.assertIn('missing a description', snapshot.failed_files[0].error)

tests/test_agent_runtime.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+import os
 import tempfile
 import unittest
 from pathlib import Path
@@ -112,6 +113,37 @@ def make_recording_streaming_urlopen_side_effect(
 
 
 class AgentRuntimeTests(unittest.TestCase):
+    def test_custom_project_agent_is_resolved_for_child_agent_configuration(self) -> None:
+        with tempfile.TemporaryDirectory() as home_dir, tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            agents_dir = workspace / '.claude' / 'agents'
+            agents_dir.mkdir(parents=True)
+            (agents_dir / 'Explore.md').write_text(
+                (
+                    '---\n'
+                    'name: Explore\n'
+                    'description: "Project-specific explore agent."\n'
+                    'tools: read_file, grep_search\n'
+                    'model: child-model\n'
+                    'initialPrompt: Start with a repository scan.\n'
+                    '---\n\n'
+                    'Search the repository and report findings.\n'
+                ),
+                encoding='utf-8',
+            )
+            with patch.dict(os.environ, {'HOME': home_dir}):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(model='parent-model'),
+                    runtime_config=AgentRuntimeConfig(cwd=workspace),
+                )
+                agent_def = agent._resolve_agent_definition({'subagent_type': 'Explore'})
+                child_model = agent._resolve_child_model_config({}, agent_def)
+                child_tools = agent._filter_tools_for_agent(agent_def)
+            self.assertEqual(agent_def.source, 'projectSettings')
+            self.assertEqual(agent_def.initial_prompt, 'Start with a repository scan.')
+            self.assertEqual(child_model.model, 'child-model')
+            self.assertEqual(sorted(child_tools), ['grep_search', 'read_file'])
+
     def test_openai_client_parses_tool_calls(self) -> None:
         responses = [
             {

tests/test_agent_slash_commands.py

@@ -4,6 +4,7 @@ import tempfile
 import unittest
 import json
 import sys
+import os
 from pathlib import Path
 from unittest.mock import patch
 
@@ -119,6 +120,35 @@ class AgentSlashCommandTests(unittest.TestCase):
         self.assertIn('Hard input limit', result.final_output)
         self.assertIn('Auto-compact buffer', result.final_output)
 
+    def test_agents_command_lists_and_shows_custom_agents(self) -> None:
+        with tempfile.TemporaryDirectory() as home_dir, tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            agents_dir = workspace / '.claude' / 'agents'
+            agents_dir.mkdir(parents=True)
+            (agents_dir / 'reviewer.md').write_text(
+                (
+                    '---\n'
+                    'name: reviewer\n'
+                    'description: "Review implementation changes carefully."\n'
+                    'tools: read_file, grep_search\n'
+                    'model: test-child-model\n'
+                    '---\n\n'
+                    'Inspect code changes and summarize risks.\n'
+                ),
+                encoding='utf-8',
+            )
+            with patch.dict(os.environ, {'HOME': home_dir}):
+                agent = LocalCodingAgent(
+                    model_config=ModelConfig(model='test-model'),
+                    runtime_config=AgentRuntimeConfig(cwd=workspace),
+                )
+                list_result = agent.run('/agents')
+                detail_result = agent.run('/agents show reviewer')
+        self.assertIn('# Agents', list_result.final_output)
+        self.assertIn('reviewer [projectSettings]', list_result.final_output)
+        self.assertIn('# Agent: reviewer', detail_result.final_output)
+        self.assertIn('Inspect code changes and summarize risks.', detail_result.final_output)
+
     def test_mcp_and_resource_commands_render_local_reports(self) -> None:
         with tempfile.TemporaryDirectory() as tmp_dir:
             workspace = Path(tmp_dir)

tests/test_main.py

@@ -213,6 +213,14 @@ class MainCliTests(unittest.TestCase):
         self.assertEqual(args.command, 'token-budget')
         self.assertEqual(args.cwd, '.')
 
+    def test_parser_accepts_agents_command(self) -> None:
+        parser = build_parser()
+        args = parser.parse_args(['agents', 'reviewer', '--cwd', '.', '--all'])
+        self.assertEqual(args.command, 'agents')
+        self.assertEqual(args.agent_type, 'reviewer')
+        self.assertTrue(args.all)
+        self.assertEqual(args.cwd, '.')
+
     def test_parser_accepts_team_runtime_commands(self) -> None:
         parser = build_parser()
         args = parser.parse_args(['team-create', 'reviewers', '--member', 'alice', '--cwd', '.'])