# Todo 46.1 Mode Parity and Duplicate Call Safety Plan

**Status:** done

## Result

Added pre-side-effect duplicate ID rejection, ordered concurrent direct execution, and symmetric event-budget enforcement for direct and dual modes. Specification and quality gates passed with no Critical/Important findings.

## Goal

Remove three review-confirmed sources of unsafe or unfair comparison behavior between `dual_agent` and `chat_agent_tools`.

## Scope

- Detect provider tool-call IDs already declared in active direct-mode history before creating a new assistant transcript or executing handlers.
- Prevent duplicate IDs within a batch and across rounds from causing repeated side effects.
- Execute direct-mode batches concurrently while preserving provider call order in returned tool messages.
- Apply `max_event_loops` acceptance to dual text events as well as direct provider calls.

## Boundaries

- A duplicate provider call ID should fail the current runtime before the duplicate handler runs; do not invent a second invalid assistant/tool transcript.
- Use ordinary `asyncio.gather` parity for this todo; bounded concurrency, conflict classes, terminal barriers, and timeout policy remain Todo 48.
- Preserve visible reply streaming that occurred before a duplicate is detected.

## Files

- Modify: `src/agent_lab/application/runtime.py`
- Modify: `tests/test_debug_runtime.py`

## Requirement Execution Loop

### Plan

1. Add RED one-shot and session tests for duplicate provider IDs across rounds; handler call count must remain one.
2. Add a timing/overlap RED test proving two direct async handlers start before either finishes and replies retain input order.
3. Add RED dual-mode tests proving events after budget exhaustion are ignored and the loop terminates.
4. Implement pre-execution ID validation, concurrent direct execution, and symmetric budget acceptance.
5. Run focused/full verification and renewed reviews.

### Observe / Update

Close Todo 46 only when both modes differ only in orchestration protocol, not duplicate safety, event budget, or handler scheduling semantics.

## Verification

- `UV_CACHE_DIR=.uv-cache uv run pytest tests/test_debug_runtime.py -q`
- `UV_CACHE_DIR=.uv-cache uv run pytest`
- `git diff --check`