Adds a complete approval flow that mirrors v1 behavior, using the
existing v1 security controls (Tool::requires_approval, auto-approve
sets, StatusUpdate::ApprovalNeeded).
## How it works
### Step 1: Tool blocked at execution
When the LLM's code calls a tool (e.g., `shell("ls")`):
1. EffectBridgeAdapter.execute_action() looks up the Tool object
2. Calls tool.requires_approval(¶ms) — returns ApprovalRequirement
3. If Always → EngineError::LeaseDenied (always blocks)
4. If UnlessAutoApproved → checks auto_approved HashSet → if not in set,
returns EngineError::LeaseDenied
5. If Never → proceeds to execution
### Step 2: Engine returns NeedApproval
The LeaseDenied error propagates through:
- CodeAct path: becomes Python RuntimeError, code halts, thread returns
NeedApproval with action_name + parameters
- Structured path: same via ActionResult.is_error
### Step 3: Router stores pending approval
- PendingApproval { action_name, original_content } stored on EngineState
- StatusUpdate::ApprovalNeeded sent to channel (shows approval card in
CLI/web with tool name, parameters, yes/always/no buttons)
- Returns text: "Tool 'shell' requires approval. Reply yes/always/no."
### Step 4: User responds
handle_message() intercepts Submission::ApprovalResponse when ENGINE_V2:
- 'yes' → auto_approve_tool(name) on EffectBridgeAdapter, re-processes
original message (tool now passes the approval check on second run)
- 'always' → same + logs for session persistence
- 'no' → returns "Denied: tool was not executed."
### Key design choice
Instead of pausing/resuming mid-execution (which needs engine changes
to freeze/restore the Monty VM state), we auto-approve the tool and
re-run the full message. The EffectBridgeAdapter's auto_approved set
persists across runs, so the second execution passes immediately.
This trades one extra LLM call for zero engine modifications.
## Files changed
- src/bridge/router.rs: PendingApproval struct, handle_approval(),
NeedApproval → StatusUpdate::ApprovalNeeded conversion
- src/bridge/mod.rs: export handle_approval
- src/agent/agent_loop.rs: intercept ApprovalResponse for engine v2
- src/bridge/effect_adapter.rs: fmt fixes
151 tests passing, clippy + fmt clean.
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
The check was looking for "[" + "result]" in System-role messages only,
but tool output metadata is added with patterns like "[shell result]"
and may appear in messages with any role. Changed to scan all messages
for " result]" or " error]" patterns regardless of role.
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
Enable with ENGINE_V2_TRACE=1 to get full execution traces and
automatic issue detection after each thread completes.
Trace recording (executor/trace.rs):
- build_trace(): captures full thread state — messages (with full
content), events, step count, token usage, detected issues
- write_trace(): writes JSON to engine_trace_{timestamp}.json
- log_trace_summary(): logs summary + issues at info/warn level
Retrospective analyzer detects 8 issue categories:
- thread_failure: thread ended in Failed state
- no_response: no assistant message generated
- tool_error: specific tool failures with error details
- code_error: Python errors (NameError, SyntaxError, etc.) in output
- missing_tool_output: tool results exist but not in system messages
- excessive_steps: >10 steps (may be stuck in loop)
- no_tools_used: single-step answer without tools (hallucination risk)
- mixed_mode: text responses without code blocks (prompt not followed)
Thread state now saved to store after execution completes (for trace
access after join_thread).
Usage:
ENGINE_V2=true ENGINE_V2_TRACE=1 cargo run
# After each message: trace JSON + issue log in terminal
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
