Created src/prompt_constants.py (550+ lines) porting all constants from npm src/constants/:

┌──────────────────┬───────────────────────────┬───────────────────────────────────────────────┐
│ Category         │ npm Source                │ Items                                         │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Product metadata │ product.ts                │ URLs, base URLs                               │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ System prefixes  │ system.ts                 │ 3 prompt prefixes                             │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Cyber risk       │ cyberRiskInstruction.ts   │ Safety instruction                            │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ API limits       │ apiLimits.ts              │ 10 image/PDF/media limits                     │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Tool limits      │ toolLimits.ts             │ 6 result size constants                       │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Spinner verbs    │ spinnerVerbs.ts           │ 187 whimsical gerunds                         │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Completion verbs │ turnCompletionVerbs.ts    │ 8 past-tense verbs                            │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Figures/symbols  │ figures.ts                │ 25 Unicode UI symbols                         │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ XML tags         │ xml.ts                    │ 30+ tag constants                             │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Messages         │ messages.ts               │ NO_CONTENT_MESSAGE                            │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Date utilities   │ common.ts                 │ 4 functions                                   │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Section caching  │ systemPromptSections.ts   │ Memoized/volatile sections                    │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Output styles    │ outputStyles.ts           │ 3 built-in configs                            │
├──────────────────┼───────────────────────────┼───────────────────────────────────────────────┤
│ Prompt helpers   │ prompts.ts                │ Knowledge cutoff, language, scratchpad, hooks │
└──────────────────┴───────────────────────────┴───────────────────────────────────────────────┘

91 new tests in tests/test_prompt_constants.py. All 17 SQL todos done.

tests/test_bash_security.py

@@ -0,0 +1,878 @@
+"""
+Tests for bash_security module.
+
+Tests are organized by validator function, matching the npm test structure.
+"""
+
+import pytest
+
+from src.bash_security import (
+    SecurityBehavior,
+    SecurityResult,
+    ValidationContext,
+    bash_command_is_safe,
+    check_shell_security,
+    extract_quoted_content,
+    get_destructive_command_warning,
+    has_unescaped_char,
+    interpret_command_result,
+    is_command_read_only,
+    split_command,
+    strip_safe_redirections,
+    validate_backslash_escaped_operators,
+    validate_backslash_escaped_whitespace,
+    validate_brace_expansion,
+    validate_carriage_return,
+    validate_comment_quote_desync,
+    validate_control_characters,
+    validate_dangerous_patterns,
+    validate_dangerous_variables,
+    validate_empty,
+    validate_git_commit,
+    validate_ifs_injection,
+    validate_incomplete_commands,
+    validate_jq_command,
+    validate_mid_word_hash,
+    validate_newlines,
+    validate_obfuscated_flags,
+    validate_proc_environ_access,
+    validate_quoted_newline,
+    validate_redirections,
+    validate_shell_metacharacters,
+    validate_unicode_whitespace,
+    validate_zsh_dangerous_commands,
+)
+
+
+# ---- Helper to build a context ----
+
+def _ctx(cmd: str) -> ValidationContext:
+    """Build a ValidationContext for the given command."""
+    base = cmd.strip().split()[0] if cmd.strip() else ''
+    with_dq, fully_unq, keep_qc = extract_quoted_content(cmd)
+    return ValidationContext(
+        original_command=cmd,
+        base_command=base,
+        unquoted_content=with_dq,
+        fully_unquoted_content=strip_safe_redirections(fully_unq),
+        fully_unquoted_pre_strip=fully_unq,
+        unquoted_keep_quote_chars=keep_qc,
+    )
+
+
+# ===========================================================================
+# extract_quoted_content
+# ===========================================================================
+
+class TestExtractQuotedContent:
+    def test_no_quotes(self):
+        dq, full, kqc = extract_quoted_content('echo hello')
+        assert dq == 'echo hello'
+        assert full == 'echo hello'
+
+    def test_single_quotes_stripped(self):
+        dq, full, kqc = extract_quoted_content("echo 'hello world'")
+        assert 'hello world' not in full
+        assert 'echo' in full
+
+    def test_double_quotes_in_dq_output(self):
+        dq, full, kqc = extract_quoted_content('echo "hello world"')
+        assert 'hello world' in dq  # double-quoted content preserved in dq
+        assert 'hello world' not in full  # but stripped in fully_unquoted
+
+    def test_escape_handling(self):
+        dq, full, kqc = extract_quoted_content('echo \\$HOME')
+        assert '$HOME' in full
+
+    def test_keep_quote_chars(self):
+        _, _, kqc = extract_quoted_content("echo 'x'#")
+        assert "'" in kqc  # quote chars preserved
+
+
+# ===========================================================================
+# strip_safe_redirections
+# ===========================================================================
+
+class TestStripSafeRedirections:
+    def test_dev_null_output(self):
+        assert '>/dev/null' not in strip_safe_redirections('cmd > /dev/null')
+
+    def test_stderr_redirect(self):
+        assert '2>&1' not in strip_safe_redirections('cmd 2>&1')
+
+    def test_dev_null_input(self):
+        assert '</dev/null' not in strip_safe_redirections('cmd < /dev/null')
+
+    def test_preserves_other_redirections(self):
+        result = strip_safe_redirections('cmd > output.txt')
+        assert '> output.txt' in result
+
+
+# ===========================================================================
+# has_unescaped_char
+# ===========================================================================
+
+class TestHasUnescapedChar:
+    def test_unescaped_backtick(self):
+        assert has_unescaped_char('echo `date`', '`') is True
+
+    def test_escaped_backtick(self):
+        assert has_unescaped_char('echo \\`safe\\`', '`') is False
+
+    def test_double_backslash_then_backtick(self):
+        # \\\` → \\ (literal backslash) + ` (unescaped)
+        assert has_unescaped_char('test\\\\`date`', '`') is True
+
+    def test_no_match(self):
+        assert has_unescaped_char('echo hello', '`') is False
+
+
+# ===========================================================================
+# split_command
+# ===========================================================================
+
+class TestSplitCommand:
+    def test_simple(self):
+        assert split_command('echo hello') == ['echo hello']
+
+    def test_semicolon(self):
+        assert split_command('echo a; echo b') == ['echo a', 'echo b']
+
+    def test_and_and(self):
+        assert split_command('cmd1 && cmd2') == ['cmd1', 'cmd2']
+
+    def test_pipe(self):
+        assert split_command('cat file | grep pattern') == ['cat file', 'grep pattern']
+
+    def test_or_or(self):
+        assert split_command('cmd1 || cmd2') == ['cmd1', 'cmd2']
+
+    def test_quotes_preserved(self):
+        result = split_command("echo 'a; b'")
+        assert len(result) == 1  # semicolon inside quotes not split
+
+    def test_complex(self):
+        result = split_command('cd /tmp && echo hi; ls | head')
+        assert len(result) == 4
+
+
+# ===========================================================================
+# validate_empty
+# ===========================================================================
+
+class TestValidateEmpty:
+    def test_empty(self):
+        assert validate_empty(_ctx('')).behavior == SecurityBehavior.ALLOW
+
+    def test_whitespace_only(self):
+        assert validate_empty(_ctx('   ')).behavior == SecurityBehavior.ALLOW
+
+    def test_non_empty(self):
+        assert validate_empty(_ctx('ls')).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_control_characters
+# ===========================================================================
+
+class TestValidateControlCharacters:
+    def test_null_byte(self):
+        result = validate_control_characters(_ctx('echo\x00hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_bell(self):
+        result = validate_control_characters(_ctx('echo\x07hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean_command(self):
+        result = validate_control_characters(_ctx('echo hello'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_tab_allowed(self):
+        result = validate_control_characters(_ctx('echo\thello'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_newline_allowed(self):
+        result = validate_control_characters(_ctx('echo\nhello'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_incomplete_commands
+# ===========================================================================
+
+class TestValidateIncompleteCommands:
+    def test_starts_with_tab(self):
+        result = validate_incomplete_commands(_ctx('\techo hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_starts_with_dash(self):
+        result = validate_incomplete_commands(_ctx('-rf /'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_starts_with_operator(self):
+        result = validate_incomplete_commands(_ctx('&& echo hello'))
+        assert result.behavior == SecurityBehavior.ASK
+        result = validate_incomplete_commands(_ctx('; echo hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_normal_command(self):
+        result = validate_incomplete_commands(_ctx('ls -la'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_git_commit
+# ===========================================================================
+
+class TestValidateGitCommit:
+    def test_not_git(self):
+        result = validate_git_commit(_ctx('echo hello'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_simple_commit(self):
+        result = validate_git_commit(_ctx("git commit -m 'initial commit'"))
+        assert result.behavior == SecurityBehavior.ALLOW
+
+    def test_double_quoted_commit(self):
+        result = validate_git_commit(_ctx('git commit -m "fix bug"'))
+        assert result.behavior == SecurityBehavior.ALLOW
+
+    def test_commit_with_substitution(self):
+        result = validate_git_commit(_ctx('git commit -m "$(date)"'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_commit_with_backtick(self):
+        result = validate_git_commit(_ctx('git commit -m "`date`"'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_commit_with_chained_commands(self):
+        result = validate_git_commit(_ctx("git commit -m 'msg'; rm -rf /"))
+        # Should passthrough (not early-allow) due to ; in remainder
+        assert result.behavior != SecurityBehavior.ALLOW
+
+    def test_commit_with_backslash(self):
+        result = validate_git_commit(_ctx('git commit -m "test\\"msg"'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_jq_command
+# ===========================================================================
+
+class TestValidateJqCommand:
+    def test_not_jq(self):
+        assert validate_jq_command(_ctx('echo hi')).behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_jq_system(self):
+        result = validate_jq_command(_ctx('jq "system(\"rm -rf /\")"'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_jq_from_file(self):
+        result = validate_jq_command(_ctx('jq -f evil.jq'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_jq_slurpfile(self):
+        result = validate_jq_command(_ctx('jq --slurpfile x data.json'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_safe_jq(self):
+        result = validate_jq_command(_ctx('jq ".name" data.json'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_obfuscated_flags
+# ===========================================================================
+
+class TestValidateObfuscatedFlags:
+    def test_ansi_c_quoting(self):
+        result = validate_obfuscated_flags(_ctx("find . $'-exec' evil"))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_locale_quoting(self):
+        result = validate_obfuscated_flags(_ctx('find . $"-exec" evil'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_echo_safe(self):
+        result = validate_obfuscated_flags(_ctx("echo $'hello'"))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_empty_quotes_before_dash(self):
+        result = validate_obfuscated_flags(_ctx("find . '' -exec evil"))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_quoted_flag(self):
+        result = validate_obfuscated_flags(_ctx('find . "-exec" rm {} ;'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_normal_command(self):
+        result = validate_obfuscated_flags(_ctx('ls -la'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_three_consecutive_quotes(self):
+        result = validate_obfuscated_flags(_ctx("find . '''exec"))
+        assert result.behavior == SecurityBehavior.ASK
+
+
+# ===========================================================================
+# validate_shell_metacharacters
+# ===========================================================================
+
+class TestValidateShellMetacharacters:
+    def test_semicolon_in_quotes(self):
+        result = validate_shell_metacharacters(_ctx('echo "a;b"'))
+        # unquoted_content (with_double_quotes) has the ; inside
+        assert result.behavior == SecurityBehavior.PASSTHROUGH or result.behavior == SecurityBehavior.ASK
+
+    def test_find_name_with_pipe(self):
+        # Single-quoted pipe is stripped entirely from unquoted content → safe
+        ctx = _ctx("find . -name '|evil'")
+        result = validate_shell_metacharacters(ctx)
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_double_quoted_metachar(self):
+        # Check that we catch metacharacters in unquoted positions
+        # The npm version checks the double-quote-retained string for
+        # quoted metacharacters, but we strip quote chars. So we test
+        # the actual dangerous case: unquoted semicolon
+        ctx = _ctx('find . -name evil; rm -rf /')
+        # This won't be caught by this specific validator (it looks for
+        # metacharacters INSIDE quoted args, not command separators)
+        result = validate_shell_metacharacters(ctx)
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_clean_command(self):
+        assert validate_shell_metacharacters(_ctx('ls -la')).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_dangerous_variables
+# ===========================================================================
+
+class TestValidateDangerousVariables:
+    def test_variable_in_pipe(self):
+        result = validate_dangerous_variables(_ctx('$CMD | grep x'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_variable_in_redirect(self):
+        result = validate_dangerous_variables(_ctx('echo x > $FILE'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_safe_variable(self):
+        result = validate_dangerous_variables(_ctx('echo $HOME'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_dangerous_patterns
+# ===========================================================================
+
+class TestValidateDangerousPatterns:
+    def test_backtick(self):
+        result = validate_dangerous_patterns(_ctx('echo `date`'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_dollar_paren(self):
+        result = validate_dangerous_patterns(_ctx('echo $(date)'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_dollar_brace(self):
+        result = validate_dangerous_patterns(_ctx('echo ${PATH}'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_process_substitution(self):
+        result = validate_dangerous_patterns(_ctx('diff <(cmd1) <(cmd2)'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_safe_echo(self):
+        result = validate_dangerous_patterns(_ctx('echo hello'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_escaped_backtick(self):
+        result = validate_dangerous_patterns(_ctx('echo \\`safe\\`'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_redirections
+# ===========================================================================
+
+class TestValidateRedirections:
+    def test_output_redirect(self):
+        result = validate_redirections(_ctx('echo x > file.txt'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_input_redirect(self):
+        result = validate_redirections(_ctx('cat < /etc/passwd'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_dev_null_stripped(self):
+        # >/dev/null is stripped by strip_safe_redirections
+        result = validate_redirections(_ctx('cmd > /dev/null'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_no_redirect(self):
+        result = validate_redirections(_ctx('echo hello'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_newlines
+# ===========================================================================
+
+class TestValidateNewlines:
+    def test_no_newlines(self):
+        assert validate_newlines(_ctx('echo hello')).behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_newline_with_command(self):
+        result = validate_newlines(_ctx('echo hello\nrm -rf /'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_backslash_continuation(self):
+        result = validate_newlines(_ctx('cmd \\\n--flag'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_carriage_return
+# ===========================================================================
+
+class TestValidateCarriageReturn:
+    def test_no_cr(self):
+        assert validate_carriage_return(_ctx('echo hello')).behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_cr_in_command(self):
+        result = validate_carriage_return(_ctx('echo hello\rworld'))
+        assert result.behavior == SecurityBehavior.ASK
+        assert result.is_misparsing is True
+
+    def test_cr_in_double_quotes_safe(self):
+        result = validate_carriage_return(_ctx('echo "hello\rworld"'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_ifs_injection
+# ===========================================================================
+
+class TestValidateIFSInjection:
+    def test_ifs_variable(self):
+        result = validate_ifs_injection(_ctx('echo$IFS/etc/passwd'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_ifs_expansion(self):
+        result = validate_ifs_injection(_ctx('echo ${IFS:0:1}'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean(self):
+        assert validate_ifs_injection(_ctx('echo hello')).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_proc_environ_access
+# ===========================================================================
+
+class TestValidateProcEnvironAccess:
+    def test_proc_environ(self):
+        result = validate_proc_environ_access(_ctx('cat /proc/self/environ'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_proc_pid_environ(self):
+        result = validate_proc_environ_access(_ctx('cat /proc/1/environ'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean(self):
+        assert validate_proc_environ_access(_ctx('cat /etc/hosts')).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_backslash_escaped_whitespace
+# ===========================================================================
+
+class TestValidateBackslashEscapedWhitespace:
+    def test_escaped_space(self):
+        result = validate_backslash_escaped_whitespace(_ctx('echo\\ hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_escaped_tab(self):
+        result = validate_backslash_escaped_whitespace(_ctx('echo\\\thello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean(self):
+        assert validate_backslash_escaped_whitespace(
+            _ctx('echo hello')
+        ).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_backslash_escaped_operators
+# ===========================================================================
+
+class TestValidateBackslashEscapedOperators:
+    def test_escaped_semicolon(self):
+        result = validate_backslash_escaped_operators(_ctx('cat safe.txt \\; echo /etc/passwd'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_escaped_pipe(self):
+        result = validate_backslash_escaped_operators(_ctx('cmd \\| evil'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean(self):
+        assert validate_backslash_escaped_operators(
+            _ctx('ls -la')
+        ).behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_inside_quotes_safe(self):
+        result = validate_backslash_escaped_operators(_ctx("echo '\\;'"))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_brace_expansion
+# ===========================================================================
+
+class TestValidateBraceExpansion:
+    def test_comma_expansion(self):
+        result = validate_brace_expansion(_ctx('echo {a,b,c}'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_sequence_expansion(self):
+        result = validate_brace_expansion(_ctx('echo {1..5}'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_no_expansion(self):
+        result = validate_brace_expansion(_ctx('echo {hello}'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_escaped_brace(self):
+        result = validate_brace_expansion(_ctx('echo \\{a,b\\}'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_excess_closing_braces(self):
+        result = validate_brace_expansion(_ctx("git diff {@'{'0},--output=/tmp/pwned}"))
+        assert result.behavior == SecurityBehavior.ASK
+
+
+# ===========================================================================
+# validate_unicode_whitespace
+# ===========================================================================
+
+class TestValidateUnicodeWhitespace:
+    def test_nbsp(self):
+        result = validate_unicode_whitespace(_ctx('echo\u00a0hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_em_space(self):
+        result = validate_unicode_whitespace(_ctx('echo\u2003hello'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean(self):
+        assert validate_unicode_whitespace(_ctx('echo hello')).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_mid_word_hash
+# ===========================================================================
+
+class TestValidateMidWordHash:
+    def test_mid_word_hash(self):
+        result = validate_mid_word_hash(_ctx('echotest#comment'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_word_start_hash(self):
+        result = validate_mid_word_hash(_ctx('echo # comment'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_dollar_brace_hash_safe(self):
+        # ${#var} is bash string length, should be safe
+        result = validate_mid_word_hash(_ctx('echo ${#var}'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_comment_quote_desync
+# ===========================================================================
+
+class TestValidateCommentQuoteDesync:
+    def test_quote_in_comment(self):
+        result = validate_comment_quote_desync(_ctx("echo hello # it's a comment"))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_clean_comment(self):
+        result = validate_comment_quote_desync(_ctx('echo hello # clean comment'))
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_no_comment(self):
+        assert validate_comment_quote_desync(_ctx('echo hello')).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_quoted_newline
+# ===========================================================================
+
+class TestValidateQuotedNewline:
+    def test_quoted_newline_with_hash(self):
+        result = validate_quoted_newline(_ctx("echo 'hello\n# dangerous line'"))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_no_newline(self):
+        assert validate_quoted_newline(_ctx('echo hello')).behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_newline_without_hash(self):
+        assert validate_quoted_newline(_ctx("echo 'hello\nworld'")).behavior == SecurityBehavior.PASSTHROUGH
+
+
+# ===========================================================================
+# validate_zsh_dangerous_commands
+# ===========================================================================
+
+class TestValidateZshDangerousCommands:
+    def test_zmodload(self):
+        result = validate_zsh_dangerous_commands(_ctx('zmodload zsh/system'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_zpty(self):
+        result = validate_zsh_dangerous_commands(_ctx('zpty cmd echo'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_emulate(self):
+        result = validate_zsh_dangerous_commands(_ctx('emulate -c evil'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_fc_e(self):
+        result = validate_zsh_dangerous_commands(_ctx('fc -e vim'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_normal_command(self):
+        assert validate_zsh_dangerous_commands(_ctx('ls -la')).behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_env_var_prefix(self):
+        result = validate_zsh_dangerous_commands(_ctx('FOO=bar zmodload zsh/system'))
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_precommand_modifier(self):
+        result = validate_zsh_dangerous_commands(_ctx('command zmodload zsh/system'))
+        assert result.behavior == SecurityBehavior.ASK
+
+
+# ===========================================================================
+# bash_command_is_safe (integration)
+# ===========================================================================
+
+class TestBashCommandIsSafe:
+    def test_empty_command(self):
+        result = bash_command_is_safe('')
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_simple_ls(self):
+        result = bash_command_is_safe('ls -la')
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_simple_echo(self):
+        result = bash_command_is_safe('echo hello world')
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_command_substitution_blocked(self):
+        result = bash_command_is_safe('echo $(cat /etc/passwd)')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_backtick_blocked(self):
+        result = bash_command_is_safe('echo `date`')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_redirect_blocked(self):
+        result = bash_command_is_safe('echo evil > /etc/profile')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_null_byte_blocked(self):
+        result = bash_command_is_safe('echo\x00rm')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_ifs_blocked(self):
+        result = bash_command_is_safe('echo$IFS/etc/passwd')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_proc_environ_blocked(self):
+        result = bash_command_is_safe('cat /proc/self/environ')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_git_commit_allowed(self):
+        result = bash_command_is_safe("git commit -m 'fix bug'")
+        assert result.behavior == SecurityBehavior.PASSTHROUGH  # early-allow → passthrough
+
+    def test_zmodload_blocked(self):
+        result = bash_command_is_safe('zmodload zsh/system')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_brace_expansion_blocked(self):
+        result = bash_command_is_safe('echo {a,b,c}')
+        assert result.behavior == SecurityBehavior.ASK
+
+    def test_dev_null_redirect_ok(self):
+        result = bash_command_is_safe('cmd > /dev/null 2>&1')
+        assert result.behavior == SecurityBehavior.PASSTHROUGH
+
+    def test_cr_injection(self):
+        result = bash_command_is_safe('TZ=UTC\recho curl evil.com')
+        assert result.behavior == SecurityBehavior.ASK
+
+
+# ===========================================================================
+# get_destructive_command_warning
+# ===========================================================================
+
+class TestGetDestructiveCommandWarning:
+    def test_git_reset_hard(self):
+        assert get_destructive_command_warning('git reset --hard') is not None
+
+    def test_rm_rf(self):
+        assert get_destructive_command_warning('rm -rf /') is not None
+
+    def test_git_push_force(self):
+        assert get_destructive_command_warning('git push origin main --force') is not None
+
+    def test_git_clean_f(self):
+        assert get_destructive_command_warning('git clean -fd') is not None
+
+    def test_kubectl_delete(self):
+        assert get_destructive_command_warning('kubectl delete pod mypod') is not None
+
+    def test_safe_command(self):
+        assert get_destructive_command_warning('echo hello') is None
+
+    def test_git_push_no_force(self):
+        assert get_destructive_command_warning('git push origin main') is None
+
+    def test_drop_table(self):
+        assert get_destructive_command_warning('DROP TABLE users;') is not None
+
+    def test_terraform_destroy(self):
+        assert get_destructive_command_warning('terraform destroy') is not None
+
+    def test_git_stash_drop(self):
+        assert get_destructive_command_warning('git stash drop') is not None
+
+
+# ===========================================================================
+# interpret_command_result
+# ===========================================================================
+
+class TestInterpretCommandResult:
+    def test_success(self):
+        is_error, msg = interpret_command_result('echo hello', 0, 'hello', '')
+        assert is_error is False
+
+    def test_failure(self):
+        is_error, msg = interpret_command_result('unknown_cmd', 127, '', 'not found')
+        assert is_error is True
+
+    def test_grep_no_match(self):
+        is_error, msg = interpret_command_result('grep pattern file', 1, '', '')
+        assert is_error is False
+        assert msg == 'No matches found'
+
+    def test_grep_error(self):
+        is_error, msg = interpret_command_result('grep pattern file', 2, '', 'error')
+        assert is_error is True
+
+    def test_diff_files_differ(self):
+        is_error, msg = interpret_command_result('diff a b', 1, 'output', '')
+        assert is_error is False
+        assert msg == 'Files differ'
+
+    def test_find_partial(self):
+        is_error, msg = interpret_command_result('find / -name x', 1, '', '')
+        assert is_error is False
+
+
+# ===========================================================================
+# is_command_read_only
+# ===========================================================================
+
+class TestIsCommandReadOnly:
+    def test_ls(self):
+        assert is_command_read_only('ls -la') is True
+
+    def test_cat(self):
+        assert is_command_read_only('cat file.txt') is True
+
+    def test_grep(self):
+        assert is_command_read_only('grep -r pattern .') is True
+
+    def test_git_status(self):
+        assert is_command_read_only('git status') is True
+
+    def test_git_log(self):
+        assert is_command_read_only('git log --oneline') is True
+
+    def test_git_push(self):
+        assert is_command_read_only('git push') is False
+
+    def test_rm(self):
+        assert is_command_read_only('rm file.txt') is False
+
+    def test_sed_read_only(self):
+        assert is_command_read_only("sed -n '1,5p' file") is True
+
+    def test_sed_in_place(self):
+        assert is_command_read_only("sed -i 's/old/new/' file") is False
+
+    def test_find_safe(self):
+        assert is_command_read_only('find . -name "*.py"') is True
+
+    def test_find_exec(self):
+        assert is_command_read_only('find . -exec rm {} ;') is False
+
+    def test_find_delete(self):
+        assert is_command_read_only('find . -name "*.tmp" -delete') is False
+
+    def test_echo(self):
+        assert is_command_read_only('echo hello') is True
+
+    def test_python_version(self):
+        assert is_command_read_only('python --version') is True
+
+    def test_unknown_command(self):
+        assert is_command_read_only('some_random_command') is False
+
+
+# ===========================================================================
+# check_shell_security (integration)
+# ===========================================================================
+
+class TestCheckShellSecurity:
+    def test_shell_disabled(self):
+        allowed, msg = check_shell_security('ls', allow_shell=False)
+        assert allowed is False
+        assert 'disabled' in msg.lower()
+
+    def test_safe_command_allowed(self):
+        allowed, msg = check_shell_security('ls -la')
+        assert allowed is True
+
+    def test_destructive_blocked(self):
+        allowed, msg = check_shell_security('rm -rf /', allow_destructive=False)
+        assert allowed is False
+        assert 'destructive' in msg.lower()
+
+    def test_destructive_allowed_when_enabled(self):
+        allowed, msg = check_shell_security('rm -rf /tmp/test', allow_destructive=True)
+        # rm -rf still triggers destructive check, but allow_destructive=True skips it
+        # However rm -rf may also trigger the security check for force-remove
+        # Let's check: the main security check should pass (no injection)
+        # and destructive should be allowed
+        assert allowed is True
+
+    def test_injection_blocked(self):
+        allowed, msg = check_shell_security('echo `evil`')
+        assert allowed is False
+        assert 'backtick' in msg.lower() or 'security' in msg.lower()
+
+    def test_misparsing_always_blocked(self):
+        allowed, msg = check_shell_security('echo\x00rm')
+        assert allowed is False
+
+    def test_safe_git_commit(self):
+        allowed, msg = check_shell_security("git commit -m 'fix'")
+        assert allowed is True

tests/test_compact.py

@@ -0,0 +1,405 @@
+"""Tests for src/compact.py – the conversation compaction service."""
+
+from __future__ import annotations
+
+import tempfile
+import unittest
+from dataclasses import replace
+from pathlib import Path
+from unittest.mock import MagicMock
+
+from src.agent_runtime import LocalCodingAgent
+from src.agent_session import AgentMessage, AgentSessionState
+from src.agent_types import AgentRuntimeConfig, ModelConfig
+from src.compact import (
+    AUTOCOMPACT_BUFFER_TOKENS,
+    ERROR_INCOMPLETE_RESPONSE,
+    ERROR_NOT_ENOUGH_MESSAGES,
+    CompactionResult,
+    compact_conversation,
+    format_compact_summary,
+    get_compact_prompt,
+    get_compact_user_summary_message,
+)
+
+
+class TestGetCompactPrompt(unittest.TestCase):
+    """Tests for the compact prompt builder."""
+
+    def test_basic_prompt_contains_all_nine_sections(self) -> None:
+        prompt = get_compact_prompt()
+        for section in [
+            '1. Primary Request and Intent',
+            '2. Key Technical Concepts',
+            '3. Files and Code Sections',
+            '4. Errors and fixes',
+            '5. Problem Solving',
+            '6. All user messages',
+            '7. Pending Tasks',
+            '8. Current Work',
+            '9. Optional Next Step',
+        ]:
+            self.assertIn(section, prompt, f'Missing section: {section}')
+
+    def test_no_tools_preamble_present(self) -> None:
+        prompt = get_compact_prompt()
+        self.assertIn('CRITICAL: Respond with TEXT ONLY', prompt)
+        self.assertIn('Do NOT call any tools', prompt)
+
+    def test_no_tools_trailer_present(self) -> None:
+        prompt = get_compact_prompt()
+        self.assertIn('REMINDER: Do NOT call any tools', prompt)
+
+    def test_analysis_and_summary_example_tags_present(self) -> None:
+        prompt = get_compact_prompt()
+        self.assertIn('<analysis>', prompt)
+        self.assertIn('</analysis>', prompt)
+        self.assertIn('<summary>', prompt)
+        self.assertIn('</summary>', prompt)
+
+    def test_custom_instructions_appended(self) -> None:
+        prompt = get_compact_prompt('Focus on database changes.')
+        self.assertIn('Additional Instructions:', prompt)
+        self.assertIn('Focus on database changes.', prompt)
+
+    def test_empty_custom_instructions_ignored(self) -> None:
+        prompt_no_custom = get_compact_prompt()
+        prompt_empty = get_compact_prompt('')
+        prompt_whitespace = get_compact_prompt('   ')
+        self.assertEqual(prompt_no_custom, prompt_empty)
+        self.assertEqual(prompt_no_custom, prompt_whitespace)
+
+    def test_none_custom_instructions_ignored(self) -> None:
+        prompt_none = get_compact_prompt(None)
+        prompt_no_arg = get_compact_prompt()
+        self.assertEqual(prompt_none, prompt_no_arg)
+
+
+class TestFormatCompactSummary(unittest.TestCase):
+    """Tests for the summary formatting / XML stripping."""
+
+    def test_strips_analysis_block(self) -> None:
+        raw = '<analysis>thinking here</analysis>\n\n<summary>result</summary>'
+        formatted = format_compact_summary(raw)
+        self.assertNotIn('<analysis>', formatted)
+        self.assertNotIn('thinking here', formatted)
+        self.assertIn('result', formatted)
+
+    def test_unwraps_summary_tags(self) -> None:
+        raw = '<summary>The main points.\n1. First</summary>'
+        formatted = format_compact_summary(raw)
+        self.assertNotIn('<summary>', formatted)
+        self.assertNotIn('</summary>', formatted)
+        self.assertIn('Summary:', formatted)
+        self.assertIn('The main points.', formatted)
+
+    def test_handles_no_xml_tags(self) -> None:
+        raw = 'Plain text summary without any tags.'
+        formatted = format_compact_summary(raw)
+        self.assertEqual(formatted, raw)
+
+    def test_collapses_excess_blank_lines(self) -> None:
+        raw = '<analysis>x</analysis>\n\n\n\n<summary>y</summary>'
+        formatted = format_compact_summary(raw)
+        self.assertNotIn('\n\n\n', formatted)
+
+    def test_multiline_analysis_stripped(self) -> None:
+        raw = (
+            '<analysis>\nLine 1\nLine 2\nLine 3\n</analysis>\n'
+            '<summary>Final summary</summary>'
+        )
+        formatted = format_compact_summary(raw)
+        self.assertNotIn('Line 1', formatted)
+        self.assertIn('Final summary', formatted)
+
+
+class TestGetCompactUserSummaryMessage(unittest.TestCase):
+    """Tests for the post-compact user message builder."""
+
+    def test_basic_message_structure(self) -> None:
+        msg = get_compact_user_summary_message('<summary>overview</summary>')
+        self.assertIn('continued from a previous conversation', msg)
+        self.assertIn('overview', msg)
+
+    def test_transcript_path_appended(self) -> None:
+        msg = get_compact_user_summary_message(
+            '<summary>ok</summary>',
+            transcript_path='/tmp/transcript.json',
+        )
+        self.assertIn('/tmp/transcript.json', msg)
+
+    def test_suppress_follow_up(self) -> None:
+        msg = get_compact_user_summary_message(
+            '<summary>ok</summary>',
+            suppress_follow_up=True,
+        )
+        self.assertIn('without asking the user any further questions', msg)
+
+    def test_no_suppress_follow_up_default(self) -> None:
+        msg = get_compact_user_summary_message('<summary>ok</summary>')
+        self.assertNotIn('without asking the user any further questions', msg)
+
+
+class TestCompactConversation(unittest.TestCase):
+    """Tests for the core compact_conversation() function."""
+
+    def _make_agent(self, tmp_dir: str) -> LocalCodingAgent:
+        """Create a minimal agent with a session loaded."""
+        agent = LocalCodingAgent(
+            model_config=ModelConfig(model='test-model'),
+            runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+        )
+        return agent
+
+    def _set_session(
+        self, agent: LocalCodingAgent, messages: list[AgentMessage]
+    ) -> None:
+        session = AgentSessionState(
+            system_prompt_parts=('You are a helpful assistant.',),
+            messages=messages,
+        )
+        agent.last_session = session
+
+    def _make_messages(self, count: int) -> list[AgentMessage]:
+        msgs: list[AgentMessage] = []
+        for i in range(count):
+            role = 'user' if i % 2 == 0 else 'assistant'
+            msgs.append(
+                AgentMessage(
+                    role=role,
+                    content=f'Message {i} content. ' * 10,
+                    message_id=f'msg_{i}',
+                )
+            )
+        return msgs
+
+    def test_no_session_returns_error(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            agent.last_session = None
+            result = compact_conversation(agent)
+        self.assertIsNotNone(result.error)
+        self.assertIn('Not enough', result.error)
+
+    def test_empty_session_returns_error(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            self._set_session(agent, [])
+            result = compact_conversation(agent)
+        self.assertIsNotNone(result.error)
+
+    def test_too_few_messages_returns_error(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            # With only 2 messages and preserve_count=4, nothing to compact
+            self._set_session(agent, self._make_messages(2))
+            result = compact_conversation(agent)
+        self.assertIsNotNone(result.error)
+
+    def test_successful_compaction(self) -> None:
+        """Simulate a successful model call and verify session is compacted."""
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            msgs = self._make_messages(10)
+            self._set_session(agent, msgs)
+
+            # Mock the client's complete method
+            from src.openai_compat import AssistantTurn
+            from src.agent_types import UsageStats
+
+            mock_turn = AssistantTurn(
+                content=(
+                    '<analysis>Thinking through the conversation...</analysis>\n'
+                    '<summary>\n1. Primary Request and Intent:\n'
+                    '   User wanted to test compaction.\n'
+                    '2. Key Technical Concepts:\n   - Testing\n'
+                    '3. Files and Code Sections:\n   - test.py\n'
+                    '4. Errors and fixes:\n   - None\n'
+                    '5. Problem Solving:\n   Basic testing.\n'
+                    '6. All user messages:\n   - "test compaction"\n'
+                    '7. Pending Tasks:\n   - None\n'
+                    '8. Current Work:\n   Testing compaction.\n'
+                    '9. Optional Next Step:\n   Verify it works.\n'
+                    '</summary>'
+                ),
+                tool_calls=(),
+                finish_reason='stop',
+                raw_message={},
+                usage=UsageStats(),
+            )
+            agent.client = MagicMock()
+            agent.client.complete.return_value = mock_turn
+
+            result = compact_conversation(agent)
+
+        self.assertIsNone(result.error)
+        self.assertGreater(result.pre_compact_token_count, 0)
+        # Session should have fewer messages than original 10
+        self.assertLess(
+            len(agent.last_session.messages), 10,
+            'Session should have fewer messages after compaction',
+        )
+        # Should contain a compact_boundary message
+        boundary_msgs = [
+            m for m in agent.last_session.messages
+            if m.metadata.get('kind') == 'compact_boundary'
+        ]
+        self.assertEqual(len(boundary_msgs), 1)
+        # Should contain a compact_summary message
+        summary_msgs = [
+            m for m in agent.last_session.messages
+            if m.metadata.get('kind') == 'compact_summary'
+        ]
+        self.assertEqual(len(summary_msgs), 1)
+        # Summary should not contain <analysis> block
+        self.assertNotIn('<analysis>', result.summary_text)
+        # Summary should contain the actual summary content
+        self.assertIn('User wanted to test compaction', result.summary_text)
+
+    def test_api_error_returns_compaction_error(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            self._set_session(agent, self._make_messages(10))
+
+            agent.client = MagicMock()
+            agent.client.complete.side_effect = RuntimeError('API down')
+
+            result = compact_conversation(agent)
+        self.assertIsNotNone(result.error)
+        self.assertIn('API down', result.error)
+
+    def test_empty_model_response_returns_error(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            self._set_session(agent, self._make_messages(10))
+
+            from src.openai_compat import AssistantTurn
+            from src.agent_types import UsageStats
+
+            agent.client = MagicMock()
+            agent.client.complete.return_value = AssistantTurn(
+                content='',
+                tool_calls=(),
+                finish_reason='stop',
+                raw_message={},
+                usage=UsageStats(),
+            )
+
+            result = compact_conversation(agent)
+        self.assertIsNotNone(result.error)
+
+    def test_preserves_tail_messages(self) -> None:
+        """The most recent messages should survive compaction."""
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            msgs = self._make_messages(12)
+            self._set_session(agent, msgs)
+
+            from src.openai_compat import AssistantTurn
+            from src.agent_types import UsageStats
+
+            agent.client = MagicMock()
+            agent.client.complete.return_value = AssistantTurn(
+                content='<summary>Summarised.</summary>',
+                tool_calls=(),
+                finish_reason='stop',
+                raw_message={},
+                usage=UsageStats(),
+            )
+
+            result = compact_conversation(agent)
+
+        self.assertIsNone(result.error)
+        # The last 4 messages (default preserve_count) should still be present
+        session_contents = [m.content for m in agent.last_session.messages]
+        for original_msg in msgs[-4:]:
+            self.assertIn(
+                original_msg.content,
+                session_contents,
+                f'Tail message "{original_msg.message_id}" should be preserved',
+            )
+
+    def test_custom_instructions_passed_to_prompt(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = self._make_agent(tmp_dir)
+            self._set_session(agent, self._make_messages(10))
+
+            from src.openai_compat import AssistantTurn
+            from src.agent_types import UsageStats
+
+            agent.client = MagicMock()
+            agent.client.complete.return_value = AssistantTurn(
+                content='<summary>Custom summary.</summary>',
+                tool_calls=(),
+                finish_reason='stop',
+                raw_message={},
+                usage=UsageStats(),
+            )
+
+            compact_conversation(agent, custom_instructions='Focus on CSS.')
+
+        # Check that the API was called with custom instructions in the prompt
+        call_args = agent.client.complete.call_args
+        messages = call_args[0][0]
+        last_user_msg = messages[-1]['content']
+        self.assertIn('Focus on CSS.', last_user_msg)
+        self.assertIn('Additional Instructions:', last_user_msg)
+
+
+class TestCompactSlashCommand(unittest.TestCase):
+    """Test the /compact slash command handler end-to-end."""
+
+    def test_slash_compact_returns_success_message(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            # Set up a session with enough messages
+            session = AgentSessionState(
+                system_prompt_parts=('You are a helper.',),
+                messages=[
+                    AgentMessage(role='user', content='Hello', message_id=f'u{i}')
+                    if i % 2 == 0
+                    else AgentMessage(role='assistant', content='Hi', message_id=f'a{i}')
+                    for i in range(10)
+                ],
+            )
+            agent.last_session = session
+
+            from src.openai_compat import AssistantTurn
+            from src.agent_types import UsageStats
+
+            agent.client = MagicMock()
+            agent.client.complete.return_value = AssistantTurn(
+                content='<summary>Session summarised.</summary>',
+                tool_calls=(),
+                finish_reason='stop',
+                raw_message={},
+                usage=UsageStats(),
+            )
+
+            result = agent.run('/compact')
+
+        self.assertIn('Conversation compacted', result.final_output)
+        self.assertIn('Tokens before', result.final_output)
+
+    def test_slash_compact_no_session_returns_error(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            result = agent.run('/compact')
+        self.assertIn('failed', result.final_output.lower())
+
+
+class TestConstants(unittest.TestCase):
+    """Verify key constants match the npm reference."""
+
+    def test_autocompact_buffer_tokens(self) -> None:
+        self.assertEqual(AUTOCOMPACT_BUFFER_TOKENS, 13_000)
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_cost_exit_diff.py

@@ -0,0 +1,189 @@
+"""Tests for /cost, /exit, and /diff slash commands."""
+
+from __future__ import annotations
+
+import subprocess
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+from src.agent_runtime import LocalCodingAgent
+from src.agent_slash_commands import preprocess_slash_command
+from src.agent_types import AgentRuntimeConfig, ModelConfig, UsageStats
+
+
+class TestCostCommand(unittest.TestCase):
+    """Tests for the /cost slash command."""
+
+    def test_cost_shows_zero_initially(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            result = agent.run('/cost')
+        self.assertIn('Total cost:', result.final_output)
+        self.assertIn('$0.0000', result.final_output)
+        self.assertIn('Total input tokens:', result.final_output)
+        self.assertIn('Total output tokens:', result.final_output)
+        self.assertIn('Total tokens:', result.final_output)
+
+    def test_cost_shows_accumulated_usage(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            # Simulate accumulated usage
+            agent.cumulative_usage = UsageStats(
+                input_tokens=1000,
+                output_tokens=500,
+                cache_read_input_tokens=200,
+            )
+            agent.cumulative_cost_usd = 0.05
+            result = agent.run('/cost')
+        self.assertIn('$0.05', result.final_output)
+        self.assertIn('1,000', result.final_output)
+        self.assertIn('500', result.final_output)
+        self.assertIn('Cache read tokens:', result.final_output)
+
+    def test_cost_hides_zero_cache_and_reasoning(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            agent.cumulative_usage = UsageStats(
+                input_tokens=100,
+                output_tokens=50,
+            )
+            result = agent.run('/cost')
+        # Should NOT show cache/reasoning lines when they're zero
+        self.assertNotIn('Cache read tokens:', result.final_output)
+        self.assertNotIn('Cache creation tokens:', result.final_output)
+        self.assertNotIn('Reasoning tokens:', result.final_output)
+
+    def test_cost_small_amounts_show_four_decimals(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            agent.cumulative_cost_usd = 0.0023
+            result = agent.run('/cost')
+        self.assertIn('$0.0023', result.final_output)
+
+
+class TestExitCommand(unittest.TestCase):
+    """Tests for the /exit and /quit slash commands."""
+
+    def test_exit_triggers_system_exit(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            with self.assertRaises(SystemExit) as cm:
+                agent.run('/exit')
+            self.assertEqual(cm.exception.code, 0)
+
+    def test_quit_triggers_system_exit(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            with self.assertRaises(SystemExit):
+                agent.run('/quit')
+
+
+class TestDiffCommand(unittest.TestCase):
+    """Tests for the /diff slash command."""
+
+    def test_diff_in_non_git_directory(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+            )
+            result = agent.run('/diff')
+        # In a non-git dir, git diff returns an error
+        output = result.final_output.lower()
+        self.assertTrue(
+            'no uncommitted' in output
+            or 'not a git' in output
+            or 'error' in output,
+            f'Expected a non-git or no-changes message, got: {result.final_output}',
+        )
+
+    def test_diff_in_git_repo_with_no_changes(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            subprocess.run(
+                ['git', 'init'], cwd=str(workspace),
+                capture_output=True, check=True,
+            )
+            subprocess.run(
+                ['git', 'config', 'user.email', 'test@test.com'],
+                cwd=str(workspace), capture_output=True,
+            )
+            subprocess.run(
+                ['git', 'config', 'user.name', 'Test'],
+                cwd=str(workspace), capture_output=True,
+            )
+            (workspace / 'hello.txt').write_text('hello\n')
+            subprocess.run(
+                ['git', 'add', '.'], cwd=str(workspace),
+                capture_output=True, check=True,
+            )
+            subprocess.run(
+                ['git', 'commit', '-m', 'init'], cwd=str(workspace),
+                capture_output=True, check=True,
+            )
+
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=workspace),
+            )
+            result = agent.run('/diff')
+        self.assertIn('No uncommitted changes', result.final_output)
+
+    def test_diff_shows_changes(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            workspace = Path(tmp_dir)
+            subprocess.run(
+                ['git', 'init'], cwd=str(workspace),
+                capture_output=True, check=True,
+            )
+            subprocess.run(
+                ['git', 'config', 'user.email', 'test@test.com'],
+                cwd=str(workspace), capture_output=True,
+            )
+            subprocess.run(
+                ['git', 'config', 'user.name', 'Test'],
+                cwd=str(workspace), capture_output=True,
+            )
+            (workspace / 'hello.txt').write_text('hello\n')
+            subprocess.run(
+                ['git', 'add', '.'], cwd=str(workspace),
+                capture_output=True, check=True,
+            )
+            subprocess.run(
+                ['git', 'commit', '-m', 'init'], cwd=str(workspace),
+                capture_output=True, check=True,
+            )
+            # Make a change
+            (workspace / 'hello.txt').write_text('hello world\n')
+
+            agent = LocalCodingAgent(
+                model_config=ModelConfig(model='test-model'),
+                runtime_config=AgentRuntimeConfig(cwd=workspace),
+            )
+            result = agent.run('/diff')
+        self.assertIn('hello', result.final_output)
+        self.assertIn('diff', result.final_output.lower())
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_new_slash_commands.py

@@ -0,0 +1,299 @@
+"""Tests for /files, /copy, /export, /stats, /tag, /rename, /branch, /effort, /doctor."""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+import tempfile
+import unittest
+from pathlib import Path
+
+from src.agent_runtime import LocalCodingAgent
+from src.agent_session import AgentMessage, AgentSessionState
+from src.agent_types import AgentRuntimeConfig, ModelConfig, UsageStats
+
+
+def _make_agent(tmp_dir: str) -> LocalCodingAgent:
+    return LocalCodingAgent(
+        model_config=ModelConfig(model='test-model'),
+        runtime_config=AgentRuntimeConfig(cwd=Path(tmp_dir)),
+    )
+
+
+def _set_session(agent: LocalCodingAgent, messages: list[AgentMessage]) -> None:
+    session = AgentSessionState(
+        system_prompt_parts=('You are a helper.',),
+        messages=messages,
+    )
+    agent.last_session = session
+
+
+class TestFilesCommand(unittest.TestCase):
+    def test_no_session(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/files')
+        self.assertIn('No active session', result.final_output)
+
+    def test_no_files_in_context(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='Hi'),
+            ])
+            result = agent.run('/files')
+        self.assertIn('No files loaded', result.final_output)
+
+    def test_files_from_tool_calls(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Read main.py'),
+                AgentMessage(
+                    role='assistant', content='',
+                    tool_calls=(
+                        {'id': 'tc1', 'type': 'function', 'function': {
+                            'name': 'Read',
+                            'arguments': json.dumps({'file_path': '/home/user/project/main.py'}),
+                        }},
+                    ),
+                ),
+                AgentMessage(
+                    role='tool', content='print("hello")',
+                    name='Read',
+                    tool_call_id='tc1',
+                    metadata={'path': '/home/user/project/main.py'},
+                ),
+            ])
+            result = agent.run('/files')
+        self.assertIn('Files in context', result.final_output)
+        self.assertIn('main.py', result.final_output)
+
+
+class TestCopyCommand(unittest.TestCase):
+    def test_no_session(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/copy')
+        self.assertIn('No active session', result.final_output)
+
+    def test_no_assistant_messages(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+            ])
+            result = agent.run('/copy')
+        self.assertIn('No assistant responses', result.final_output)
+
+    def test_copies_latest_response(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='First response.'),
+                AgentMessage(role='user', content='More'),
+                AgentMessage(role='assistant', content='Second response with details.'),
+            ])
+            result = agent.run('/copy')
+        self.assertIn('Copied', result.final_output)
+        self.assertIn('response.md', result.final_output)
+        # Verify the file was written
+        tmp_file = Path(tempfile.gettempdir()) / 'claw-code' / 'response.md'
+        self.assertTrue(tmp_file.exists())
+        content = tmp_file.read_text()
+        self.assertEqual(content, 'Second response with details.')
+
+    def test_copies_nth_response(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='First.'),
+                AgentMessage(role='user', content='More'),
+                AgentMessage(role='assistant', content='Second.'),
+            ])
+            result = agent.run('/copy 1')
+        tmp_file = Path(tempfile.gettempdir()) / 'claw-code' / 'response.md'
+        content = tmp_file.read_text()
+        self.assertEqual(content, 'First.')
+
+
+class TestExportCommand(unittest.TestCase):
+    def test_no_session(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/export')
+        self.assertIn('No active session', result.final_output)
+
+    def test_exports_with_auto_filename(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='Hi there'),
+            ])
+            result = agent.run('/export')
+        self.assertIn('Exported 2 messages', result.final_output)
+        self.assertIn('.txt', result.final_output)
+
+    def test_exports_with_custom_filename(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='Hi'),
+            ])
+            result = agent.run('/export my_chat')
+            self.assertIn('my_chat.txt', result.final_output)
+            out_file = Path(tmp) / 'my_chat.txt'
+            self.assertTrue(out_file.exists())
+            content = out_file.read_text()
+            self.assertIn('Hello', content)
+            self.assertIn('Hi', content)
+
+
+class TestStatsCommand(unittest.TestCase):
+    def test_shows_statistics(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='Hi'),
+                AgentMessage(role='user', content='Question'),
+            ])
+            agent.cumulative_usage = UsageStats(input_tokens=500, output_tokens=200)
+            result = agent.run('/stats')
+        self.assertIn('Session Statistics', result.final_output)
+        self.assertIn('3 total', result.final_output)
+        self.assertIn('2 user', result.final_output)
+        self.assertIn('1 assistant', result.final_output)
+        self.assertIn('500', result.final_output)
+        self.assertIn('200', result.final_output)
+
+
+class TestTagCommand(unittest.TestCase):
+    def test_no_tags_initially(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/tag')
+        self.assertIn('No tags set', result.final_output)
+
+    def test_add_tag(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/tag important')
+        self.assertIn('Added tag: important', result.final_output)
+
+    def test_toggle_tag(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            agent.run('/tag my-tag')
+            result = agent.run('/tag my-tag')
+        self.assertIn('Removed tag: my-tag', result.final_output)
+
+    def test_list_tags(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            agent.run('/tag alpha')
+            agent.run('/tag beta')
+            result = agent.run('/tag')
+        self.assertIn('alpha', result.final_output)
+        self.assertIn('beta', result.final_output)
+
+
+class TestRenameCommand(unittest.TestCase):
+    def test_no_name(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/rename')
+        self.assertIn('Usage', result.final_output)
+
+    def test_rename_session(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/rename My Cool Session')
+        self.assertIn('renamed to: My Cool Session', result.final_output)
+
+
+class TestBranchCommand(unittest.TestCase):
+    def test_no_session(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/branch')
+        self.assertIn('No active session', result.final_output)
+
+    def test_branch_with_session(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+                AgentMessage(role='assistant', content='Hi'),
+            ])
+            result = agent.run('/branch my-feature')
+        self.assertIn('Created branch "my-feature"', result.final_output)
+        self.assertIn('Saved to:', result.final_output)
+
+    def test_branch_auto_name(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            _set_session(agent, [
+                AgentMessage(role='user', content='Hello'),
+            ])
+            result = agent.run('/branch')
+        self.assertIn('Created branch "branch-', result.final_output)
+
+
+class TestEffortCommand(unittest.TestCase):
+    def test_show_current_effort(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/effort')
+        self.assertIn('Current effort level: auto', result.final_output)
+
+    def test_set_effort_level(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/effort high')
+        self.assertIn('Set effort level to: high', result.final_output)
+
+    def test_invalid_effort_level(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/effort extreme')
+        self.assertIn('Invalid effort level', result.final_output)
+
+    def test_all_valid_levels(self) -> None:
+        for level in ('low', 'medium', 'high', 'max', 'auto'):
+            with tempfile.TemporaryDirectory() as tmp:
+                agent = _make_agent(tmp)
+                result = agent.run(f'/effort {level}')
+            self.assertIn(f'Set effort level to: {level}', result.final_output)
+
+
+class TestDoctorCommand(unittest.TestCase):
+    def test_shows_report(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            agent = _make_agent(tmp)
+            result = agent.run('/doctor')
+        output = result.final_output
+        self.assertIn('Doctor Report', output)
+        self.assertIn('Python version', output)
+        self.assertIn('git', output)
+        self.assertIn('Model', output)
+        self.assertIn('Working directory', output)
+
+    def test_detects_claude_md(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            (Path(tmp) / 'CLAUDE.md').write_text('memory file')
+            agent = _make_agent(tmp)
+            result = agent.run('/doctor')
+        self.assertIn('CLAUDE.md', result.final_output)
+        self.assertIn('found', result.final_output)
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_prompt_constants.py

@@ -0,0 +1,643 @@
+"""Tests for prompt_constants module.
+
+Validates that all constants ported from npm src/constants/ are present,
+correctly typed, and that helper functions behave as expected.
+"""
+
+from __future__ import annotations
+
+import os
+import platform
+from unittest.mock import patch
+
+import pytest
+
+from src.prompt_constants import (
+    # Product metadata
+    PRODUCT_URL,
+    CLAUDE_AI_BASE_URL,
+    # System prompt prefixes
+    DEFAULT_SYSPROMPT_PREFIX,
+    AGENT_SDK_CLAUDE_CODE_PRESET_PREFIX,
+    AGENT_SDK_PREFIX,
+    CLI_SYSPROMPT_PREFIXES,
+    # Cyber risk
+    CYBER_RISK_INSTRUCTION,
+    # API limits
+    API_IMAGE_MAX_BASE64_SIZE,
+    IMAGE_TARGET_RAW_SIZE,
+    IMAGE_MAX_WIDTH,
+    IMAGE_MAX_HEIGHT,
+    PDF_TARGET_RAW_SIZE,
+    API_PDF_MAX_PAGES,
+    PDF_EXTRACT_SIZE_THRESHOLD,
+    PDF_MAX_EXTRACT_SIZE,
+    PDF_MAX_PAGES_PER_READ,
+    PDF_AT_MENTION_INLINE_THRESHOLD,
+    API_MAX_MEDIA_PER_REQUEST,
+    # Tool limits
+    DEFAULT_MAX_RESULT_SIZE_CHARS,
+    MAX_TOOL_RESULT_TOKENS,
+    BYTES_PER_TOKEN,
+    MAX_TOOL_RESULT_BYTES,
+    MAX_TOOL_RESULTS_PER_MESSAGE_CHARS,
+    TOOL_SUMMARY_MAX_LENGTH,
+    # Spinner verbs
+    SPINNER_VERBS,
+    # Turn completion verbs
+    TURN_COMPLETION_VERBS,
+    # Figures
+    BLACK_CIRCLE,
+    BULLET_OPERATOR,
+    TEARDROP_ASTERISK,
+    UP_ARROW,
+    DOWN_ARROW,
+    LIGHTNING_BOLT,
+    EFFORT_LOW,
+    EFFORT_MEDIUM,
+    EFFORT_HIGH,
+    EFFORT_MAX,
+    PLAY_ICON,
+    PAUSE_ICON,
+    REFRESH_ARROW,
+    CHANNEL_ARROW,
+    INJECTED_ARROW,
+    FORK_GLYPH,
+    DIAMOND_OPEN,
+    DIAMOND_FILLED,
+    REFERENCE_MARK,
+    FLAG_ICON,
+    BLOCKQUOTE_BAR,
+    HEAVY_HORIZONTAL,
+    BRIDGE_SPINNER_FRAMES,
+    BRIDGE_READY_INDICATOR,
+    BRIDGE_FAILED_INDICATOR,
+    # XML tags
+    COMMAND_NAME_TAG,
+    COMMAND_MESSAGE_TAG,
+    COMMAND_ARGS_TAG,
+    BASH_INPUT_TAG,
+    BASH_STDOUT_TAG,
+    BASH_STDERR_TAG,
+    LOCAL_COMMAND_STDOUT_TAG,
+    LOCAL_COMMAND_STDERR_TAG,
+    LOCAL_COMMAND_CAVEAT_TAG,
+    TERMINAL_OUTPUT_TAGS,
+    TICK_TAG,
+    TASK_NOTIFICATION_TAG,
+    TASK_ID_TAG,
+    TOOL_USE_ID_TAG,
+    TASK_TYPE_TAG,
+    OUTPUT_FILE_TAG,
+    STATUS_TAG,
+    SUMMARY_TAG,
+    REASON_TAG,
+    WORKTREE_TAG,
+    WORKTREE_PATH_TAG,
+    WORKTREE_BRANCH_TAG,
+    ULTRAPLAN_TAG,
+    REMOTE_REVIEW_TAG,
+    REMOTE_REVIEW_PROGRESS_TAG,
+    TEAMMATE_MESSAGE_TAG,
+    CHANNEL_MESSAGE_TAG,
+    CHANNEL_TAG,
+    CROSS_SESSION_MESSAGE_TAG,
+    FORK_BOILERPLATE_TAG,
+    FORK_DIRECTIVE_PREFIX,
+    COMMON_HELP_ARGS,
+    COMMON_INFO_ARGS,
+    # Messages
+    NO_CONTENT_MESSAGE,
+    # Date utilities
+    get_local_iso_date,
+    get_session_start_date,
+    reset_session_start_date,
+    get_local_month_year,
+    # System prompt section caching
+    SystemPromptSection,
+    system_prompt_section,
+    dangerous_uncached_system_prompt_section,
+    resolve_system_prompt_sections,
+    clear_system_prompt_sections,
+    # Output styles
+    DEFAULT_OUTPUT_STYLE_NAME,
+    OutputStyleConfig,
+    OUTPUT_STYLE_CONFIGS,
+    # Knowledge cutoff
+    FRONTIER_MODEL_NAME,
+    get_knowledge_cutoff,
+    CLAUDE_MODEL_IDS,
+    # Prompt sections
+    HOOKS_SECTION,
+    SYSTEM_REMINDERS_SECTION,
+    SUMMARIZE_TOOL_RESULTS_SECTION,
+    DEFAULT_AGENT_PROMPT,
+    SYSTEM_PROMPT_DYNAMIC_BOUNDARY,
+    get_language_section,
+    get_output_style_section,
+    get_scratchpad_instructions,
+    # Error IDs
+    E_TOOL_USE_SUMMARY_GENERATION_FAILED,
+)
+
+
+# =========================================================================
+# Product metadata
+# =========================================================================
+
+class TestProductMetadata:
+    def test_product_url(self):
+        assert PRODUCT_URL == "https://claude.com/claude-code"
+
+    def test_claude_ai_base_url(self):
+        assert CLAUDE_AI_BASE_URL == "https://claude.ai"
+
+
+# =========================================================================
+# System prompt prefixes
+# =========================================================================
+
+class TestSystemPromptPrefixes:
+    def test_default_prefix_content(self):
+        assert "Claude Code" in DEFAULT_SYSPROMPT_PREFIX
+        assert "Anthropic" in DEFAULT_SYSPROMPT_PREFIX
+
+    def test_agent_sdk_prefix_content(self):
+        assert "Agent SDK" in AGENT_SDK_PREFIX
+
+    def test_cli_sysprompt_prefixes_is_frozenset(self):
+        assert isinstance(CLI_SYSPROMPT_PREFIXES, frozenset)
+        assert len(CLI_SYSPROMPT_PREFIXES) == 3
+
+    def test_all_prefixes_in_set(self):
+        assert DEFAULT_SYSPROMPT_PREFIX in CLI_SYSPROMPT_PREFIXES
+        assert AGENT_SDK_CLAUDE_CODE_PRESET_PREFIX in CLI_SYSPROMPT_PREFIXES
+        assert AGENT_SDK_PREFIX in CLI_SYSPROMPT_PREFIXES
+
+
+# =========================================================================
+# Cyber risk
+# =========================================================================
+
+class TestCyberRisk:
+    def test_instruction_mentions_ctf(self):
+        assert "CTF" in CYBER_RISK_INSTRUCTION
+
+    def test_instruction_mentions_dos(self):
+        assert "DoS" in CYBER_RISK_INSTRUCTION
+
+
+# =========================================================================
+# API limits
+# =========================================================================
+
+class TestAPILimits:
+    def test_image_base64_size(self):
+        assert API_IMAGE_MAX_BASE64_SIZE == 5 * 1024 * 1024
+
+    def test_image_target_raw_size(self):
+        assert IMAGE_TARGET_RAW_SIZE == (API_IMAGE_MAX_BASE64_SIZE * 3) // 4
+
+    def test_image_dimensions(self):
+        assert IMAGE_MAX_WIDTH == 2000
+        assert IMAGE_MAX_HEIGHT == 2000
+
+    def test_pdf_target_raw_size(self):
+        assert PDF_TARGET_RAW_SIZE == 20 * 1024 * 1024
+
+    def test_pdf_max_pages(self):
+        assert API_PDF_MAX_PAGES == 100
+
+    def test_pdf_extract_threshold(self):
+        assert PDF_EXTRACT_SIZE_THRESHOLD == 3 * 1024 * 1024
+
+    def test_pdf_max_extract_size(self):
+        assert PDF_MAX_EXTRACT_SIZE == 100 * 1024 * 1024
+
+    def test_pdf_pages_per_read(self):
+        assert PDF_MAX_PAGES_PER_READ == 20
+
+    def test_pdf_inline_threshold(self):
+        assert PDF_AT_MENTION_INLINE_THRESHOLD == 10
+
+    def test_media_per_request(self):
+        assert API_MAX_MEDIA_PER_REQUEST == 100
+
+
+# =========================================================================
+# Tool limits
+# =========================================================================
+
+class TestToolLimits:
+    def test_default_max_result_size(self):
+        assert DEFAULT_MAX_RESULT_SIZE_CHARS == 50_000
+
+    def test_max_tool_result_tokens(self):
+        assert MAX_TOOL_RESULT_TOKENS == 100_000
+
+    def test_bytes_per_token(self):
+        assert BYTES_PER_TOKEN == 4
+
+    def test_max_tool_result_bytes_derived(self):
+        assert MAX_TOOL_RESULT_BYTES == MAX_TOOL_RESULT_TOKENS * BYTES_PER_TOKEN
+        assert MAX_TOOL_RESULT_BYTES == 400_000
+
+    def test_max_per_message_chars(self):
+        assert MAX_TOOL_RESULTS_PER_MESSAGE_CHARS == 200_000
+
+    def test_tool_summary_max_length(self):
+        assert TOOL_SUMMARY_MAX_LENGTH == 50
+
+
+# =========================================================================
+# Spinner verbs
+# =========================================================================
+
+class TestSpinnerVerbs:
+    def test_is_tuple(self):
+        assert isinstance(SPINNER_VERBS, tuple)
+
+    def test_count(self):
+        assert len(SPINNER_VERBS) == 187
+
+    def test_first_verb(self):
+        assert SPINNER_VERBS[0] == "Accomplishing"
+
+    def test_last_verb(self):
+        assert SPINNER_VERBS[-1] == "Zigzagging"
+
+    def test_all_strings(self):
+        for verb in SPINNER_VERBS:
+            assert isinstance(verb, str)
+
+    def test_contains_clauding(self):
+        assert "Clauding" in SPINNER_VERBS
+
+    def test_contains_thinking(self):
+        assert "Thinking" in SPINNER_VERBS
+
+    def test_no_duplicates(self):
+        assert len(SPINNER_VERBS) == len(set(SPINNER_VERBS))
+
+
+# =========================================================================
+# Turn completion verbs
+# =========================================================================
+
+class TestTurnCompletionVerbs:
+    def test_is_tuple(self):
+        assert isinstance(TURN_COMPLETION_VERBS, tuple)
+
+    def test_count(self):
+        assert len(TURN_COMPLETION_VERBS) == 8
+
+    def test_contains_worked(self):
+        assert "Worked" in TURN_COMPLETION_VERBS
+
+    def test_contains_baked(self):
+        assert "Baked" in TURN_COMPLETION_VERBS
+
+    def test_all_past_tense(self):
+        # All end in 'd' (past tense)
+        for verb in TURN_COMPLETION_VERBS:
+            assert verb[-1] == "d", f"{verb} doesn't end with 'd'"
+
+
+# =========================================================================
+# Figures / UI symbols
+# =========================================================================
+
+class TestFigures:
+    def test_black_circle_is_string(self):
+        assert isinstance(BLACK_CIRCLE, str)
+        assert len(BLACK_CIRCLE) == 1
+
+    def test_effort_symbols_are_distinct(self):
+        symbols = {EFFORT_LOW, EFFORT_MEDIUM, EFFORT_HIGH, EFFORT_MAX}
+        assert len(symbols) == 4
+
+    def test_arrows(self):
+        assert UP_ARROW == "\u2191"
+        assert DOWN_ARROW == "\u2193"
+
+    def test_bridge_spinner_frames(self):
+        assert isinstance(BRIDGE_SPINNER_FRAMES, tuple)
+        assert len(BRIDGE_SPINNER_FRAMES) == 4
+
+    def test_play_pause_icons(self):
+        assert PLAY_ICON == "\u25b6"
+        assert PAUSE_ICON == "\u23f8"
+
+    def test_diamond_symbols(self):
+        assert DIAMOND_OPEN == "\u25c7"
+        assert DIAMOND_FILLED == "\u25c6"
+
+
+# =========================================================================
+# XML tag constants
+# =========================================================================
+
+class TestXMLTags:
+    def test_command_tags(self):
+        assert COMMAND_NAME_TAG == "command-name"
+        assert COMMAND_MESSAGE_TAG == "command-message"
+        assert COMMAND_ARGS_TAG == "command-args"
+
+    def test_bash_tags(self):
+        assert BASH_INPUT_TAG == "bash-input"
+        assert BASH_STDOUT_TAG == "bash-stdout"
+        assert BASH_STDERR_TAG == "bash-stderr"
+
+    def test_terminal_output_tags_tuple(self):
+        assert isinstance(TERMINAL_OUTPUT_TAGS, tuple)
+        assert len(TERMINAL_OUTPUT_TAGS) == 6
+        assert BASH_INPUT_TAG in TERMINAL_OUTPUT_TAGS
+        assert LOCAL_COMMAND_STDOUT_TAG in TERMINAL_OUTPUT_TAGS
+
+    def test_tick_tag(self):
+        assert TICK_TAG == "tick"
+
+    def test_task_tags(self):
+        assert TASK_NOTIFICATION_TAG == "task-notification"
+        assert TASK_ID_TAG == "task-id"
+        assert TOOL_USE_ID_TAG == "tool-use-id"
+
+    def test_worktree_tags(self):
+        assert WORKTREE_TAG == "worktree"
+        assert WORKTREE_PATH_TAG == "worktreePath"
+
+    def test_fork_tags(self):
+        assert FORK_BOILERPLATE_TAG == "fork-boilerplate"
+        assert FORK_DIRECTIVE_PREFIX == "Your directive: "
+
+    def test_common_help_args(self):
+        assert isinstance(COMMON_HELP_ARGS, tuple)
+        assert "help" in COMMON_HELP_ARGS
+        assert "-h" in COMMON_HELP_ARGS
+        assert "--help" in COMMON_HELP_ARGS
+
+    def test_common_info_args(self):
+        assert isinstance(COMMON_INFO_ARGS, tuple)
+        assert "list" in COMMON_INFO_ARGS
+        assert "status" in COMMON_INFO_ARGS
+        assert "?" in COMMON_INFO_ARGS
+
+
+# =========================================================================
+# Message constants
+# =========================================================================
+
+class TestMessages:
+    def test_no_content_message(self):
+        assert NO_CONTENT_MESSAGE == "(no content)"
+
+
+# =========================================================================
+# Date utilities
+# =========================================================================
+
+class TestDateUtilities:
+    def test_get_local_iso_date_format(self):
+        d = get_local_iso_date()
+        parts = d.split("-")
+        assert len(parts) == 3
+        assert len(parts[0]) == 4  # year
+        assert len(parts[1]) == 2  # month
+        assert len(parts[2]) == 2  # day
+
+    def test_get_local_iso_date_override(self):
+        with patch.dict(os.environ, {"CLAUDE_CODE_OVERRIDE_DATE": "2025-01-15"}):
+            assert get_local_iso_date() == "2025-01-15"
+
+    def test_get_session_start_date_memoised(self):
+        reset_session_start_date()
+        d1 = get_session_start_date()
+        d2 = get_session_start_date()
+        assert d1 == d2
+
+    def test_reset_session_start_date(self):
+        reset_session_start_date()
+        d = get_session_start_date()
+        assert isinstance(d, str)
+        reset_session_start_date()
+        # After reset, should still return valid date
+        d2 = get_session_start_date()
+        assert isinstance(d2, str)
+
+    def test_get_local_month_year_format(self):
+        result = get_local_month_year()
+        parts = result.split()
+        assert len(parts) == 2
+        assert parts[1].isdigit()
+        assert len(parts[1]) == 4
+
+    def test_get_local_month_year_override(self):
+        with patch.dict(os.environ, {"CLAUDE_CODE_OVERRIDE_DATE": "2026-02-15"}):
+            assert get_local_month_year() == "February 2026"
+
+
+# =========================================================================
+# System prompt section caching
+# =========================================================================
+
+class TestSystemPromptSections:
+    def setup_method(self):
+        clear_system_prompt_sections()
+
+    def test_system_prompt_section_creates_cached(self):
+        s = system_prompt_section("test", lambda: "hello")
+        assert s.name == "test"
+        assert s.cache_break is False
+
+    def test_dangerous_uncached_creates_volatile(self):
+        s = dangerous_uncached_system_prompt_section("test", lambda: "hello", "reason")
+        assert s.name == "test"
+        assert s.cache_break is True
+
+    def test_resolve_caches_sections(self):
+        call_count = 0
+
+        def compute():
+            nonlocal call_count
+            call_count += 1
+            return f"value-{call_count}"
+
+        sections = [system_prompt_section("s1", compute)]
+        r1 = resolve_system_prompt_sections(sections)
+        r2 = resolve_system_prompt_sections(sections)
+        assert r1 == ["value-1"]
+        assert r2 == ["value-1"]  # cached
+        assert call_count == 1
+
+    def test_uncached_recomputes(self):
+        call_count = 0
+
+        def compute():
+            nonlocal call_count
+            call_count += 1
+            return f"value-{call_count}"
+
+        sections = [dangerous_uncached_system_prompt_section("s2", compute, "test")]
+        r1 = resolve_system_prompt_sections(sections)
+        r2 = resolve_system_prompt_sections(sections)
+        assert r1 == ["value-1"]
+        assert r2 == ["value-2"]  # recomputed
+        assert call_count == 2
+
+    def test_clear_resets_cache(self):
+        call_count = 0
+
+        def compute():
+            nonlocal call_count
+            call_count += 1
+            return f"value-{call_count}"
+
+        sections = [system_prompt_section("s3", compute)]
+        resolve_system_prompt_sections(sections)
+        clear_system_prompt_sections()
+        r = resolve_system_prompt_sections(sections)
+        assert r == ["value-2"]
+        assert call_count == 2
+
+    def test_resolve_handles_none(self):
+        sections = [system_prompt_section("nil", lambda: None)]
+        r = resolve_system_prompt_sections(sections)
+        assert r == [None]
+
+    def test_multiple_sections(self):
+        sections = [
+            system_prompt_section("a", lambda: "alpha"),
+            system_prompt_section("b", lambda: "beta"),
+            system_prompt_section("c", lambda: None),
+        ]
+        r = resolve_system_prompt_sections(sections)
+        assert r == ["alpha", "beta", None]
+
+
+# =========================================================================
+# Output styles
+# =========================================================================
+
+class TestOutputStyles:
+    def test_default_style_name(self):
+        assert DEFAULT_OUTPUT_STYLE_NAME == "default"
+
+    def test_default_style_is_none(self):
+        assert OUTPUT_STYLE_CONFIGS[DEFAULT_OUTPUT_STYLE_NAME] is None
+
+    def test_explanatory_exists(self):
+        style = OUTPUT_STYLE_CONFIGS["Explanatory"]
+        assert style is not None
+        assert style.name == "Explanatory"
+        assert "explains" in style.description
+
+    def test_learning_exists(self):
+        style = OUTPUT_STYLE_CONFIGS["Learning"]
+        assert style is not None
+        assert style.name == "Learning"
+        assert "hands-on" in style.description
+
+    def test_output_style_config_frozen(self):
+        style = OutputStyleConfig(
+            name="Test", description="desc", prompt="prompt"
+        )
+        with pytest.raises(Exception):
+            style.name = "other"  # type: ignore[misc]
+
+
+# =========================================================================
+# Knowledge cutoff
+# =========================================================================
+
+class TestKnowledgeCutoff:
+    def test_frontier_model_name(self):
+        assert FRONTIER_MODEL_NAME == "Claude Opus 4.6"
+
+    def test_opus_46_cutoff(self):
+        assert get_knowledge_cutoff("claude-opus-4-6-20250601") == "May 2025"
+
+    def test_sonnet_46_cutoff(self):
+        assert get_knowledge_cutoff("claude-sonnet-4-6-20250801") == "August 2025"
+
+    def test_opus_45_cutoff(self):
+        assert get_knowledge_cutoff("claude-opus-4-5-20250601") == "May 2025"
+
+    def test_haiku_cutoff(self):
+        assert get_knowledge_cutoff("claude-haiku-4-20250201") == "February 2025"
+
+    def test_sonnet_4_cutoff(self):
+        assert get_knowledge_cutoff("claude-sonnet-4-20250114") == "January 2025"
+
+    def test_unknown_model_returns_none(self):
+        assert get_knowledge_cutoff("gpt-4-turbo") is None
+
+    def test_claude_model_ids(self):
+        assert "opus" in CLAUDE_MODEL_IDS
+        assert "sonnet" in CLAUDE_MODEL_IDS
+        assert "haiku" in CLAUDE_MODEL_IDS
+
+
+# =========================================================================
+# Prompt section helpers
+# =========================================================================
+
+class TestPromptSectionHelpers:
+    def test_hooks_section_content(self):
+        assert "hooks" in HOOKS_SECTION
+        assert "user-prompt-submit-hook" in HOOKS_SECTION
+
+    def test_system_reminders_section(self):
+        assert "system-reminder" in SYSTEM_REMINDERS_SECTION
+
+    def test_summarize_tool_results(self):
+        assert "tool results" in SUMMARIZE_TOOL_RESULTS_SECTION
+
+    def test_default_agent_prompt(self):
+        assert "agent for Claude Code" in DEFAULT_AGENT_PROMPT
+
+    def test_dynamic_boundary(self):
+        assert SYSTEM_PROMPT_DYNAMIC_BOUNDARY == "__SYSTEM_PROMPT_DYNAMIC_BOUNDARY__"
+
+    def test_language_section_none_when_no_preference(self):
+        assert get_language_section(None) is None
+        assert get_language_section("") is None
+
+    def test_language_section_with_preference(self):
+        result = get_language_section("Spanish")
+        assert result is not None
+        assert "Spanish" in result
+        assert "# Language" in result
+
+    def test_output_style_section_none_when_no_config(self):
+        assert get_output_style_section(None) is None
+
+    def test_output_style_section_with_config(self):
+        config = OutputStyleConfig(
+            name="TestStyle",
+            description="A test style",
+            prompt="Be concise.",
+        )
+        result = get_output_style_section(config)
+        assert result is not None
+        assert "# Output Style: TestStyle" in result
+        assert "Be concise." in result
+
+    def test_scratchpad_none_when_no_dir(self):
+        assert get_scratchpad_instructions(None) is None
+        assert get_scratchpad_instructions("") is None
+
+    def test_scratchpad_with_dir(self):
+        result = get_scratchpad_instructions("/tmp/session-123")
+        assert result is not None
+        assert "/tmp/session-123" in result
+        assert "# Scratchpad Directory" in result
+        assert "temporary files" in result
+
+
+# =========================================================================
+# Error IDs
+# =========================================================================
+
+class TestErrorIDs:
+    def test_tool_use_summary_error(self):
+        assert E_TOOL_USE_SUMMARY_GENERATION_FAILED == 344