# Codex Task Execution Loop > Single-agent execution loop for implementation tasks. Replaces task-executor/quality-fixer subagent cycle with direct Codex skill-driven implementation and quality gates. Use when this capability is needed. - Skill: `tomevault-io/codex-task-execution-loop` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/codex-task-execution-loop` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/codex-task-execution-loop/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/codex-task-execution-loop --- # Codex Task Execution Loop ## Purpose - Execute implementation tasks safely in a single agent. - Preserve the proven 4-step quality cycle without subagents. ## Execution Contract This skill follows the non-entry execution contract standard. Required `contract_extensions`: `task_unit_id`, `cycle_index`. See [`codex-execution-contract.md`](../workflow-entry/references/codex-execution-contract.md) and [`non-entry-execution-contract-template.md`](../workflow-entry/references/non-entry-execution-contract-template.md) for full rules. ```yaml input: objective: "Implement one task unit and run quality gate" contract_extensions: { task_unit_id: "task-12.3", cycle_index: 2 } output: status: "completed" quality_gate: gate_id: "task-cycle-check" gate_type: "implementation" trigger: event: "post-cycle validation" source: "codex-task-execution-loop" criteria: - id: "task-unit-complete" description: "Task unit checks are complete" - id: "contract-aligned" description: "Cycle contract fields remain aligned" result: "pass" evidence: - check_id: "cycle-checks" status: "pass" summary: "Cycle checks passed" source_ref: ".claude/skills/codex-task-execution-loop/SKILL.md" blockers: [] branching: on_pass: "handoff" on_fail: "revise" max_cycles: 2 contract_extensions: { task_unit_id: "task-12.3", cycle_index: 2 } ``` ## Contract Compliance - Emit structured output compliant with [`codex-execution-contract.md`](../workflow-entry/references/codex-execution-contract.md). - Always include baseline output fields: `status`, `summary`, `changed_files`, `tests`, `quality_gate`, `blockers`, `next_actions`. - Validate required input fields from `../workflow-entry/references/non-entry-execution-contract-template.md` (objective, scope, constraints, acceptance_criteria, allowed_commands, sandbox_mode) before proceeding. - Echo required skill extensions in `contract_extensions`: `task_unit_id`, `cycle_index`. - Treat missing required fields as contract violations and regenerate output before handoff. - On contract violation (missing/invalid field, invalid status value, or missing extension keys): do not proceed; emit status: blocked with violation description in blockers. - Reference: [`non-entry-execution-contract-template.md`](../workflow-entry/references/non-entry-execution-contract-template.md). ## 4-Step Cycle (Mandatory Per Task) 1. Implement one task unit. 2. Run escalation check. 3. Run quality gate. 4. Decide commit readiness and report. ## Step Details ### 1) Implement one task unit - Follow `coding-principles`. - Add or update tests using `testing-principles`. - Keep change scope small enough for one review/commit unit. ### 2) Escalation check Escalate to user if any condition is true: - Requirements are unclear or changed: emit `[Stop: requirement-change-detected]` + `[Approve: route-selection]`. - Task is blocked by missing environment or permissions: emit `[Stop: quality-gate-failed]` + `[Approve: resume-after-fix]` with blocker details. - Fix would require architecture change not in design docs: emit `[Stop: high-risk-change]` + `[Approve: high-risk-change]`. ### 3) Quality gate Run and fix until stable: - Formatting/lint/static checks - Build/compile - Unit tests - Integration tests when affected Use `ai-development-guide` for anti-pattern checks and fail-fast error handling discipline. ### 4) Commit readiness and report - If all gates pass, mark task as ready. - If not, emit `[Stop: quality-gate-failed]` + `[Approve: resume-after-fix]`, then return explicit blockers and next action options. ## Hard Rules - Never batch multiple unrelated tasks in one cycle. - Never skip quality gate after implementation changes. - Never hide errors via silent fallback. - Never claim completion without verification evidence. ## Integration and E2E Handling - Use `integration-e2e-testing` when adding or changing cross-component behavior. - Keep integration tests close to implementation. - Run E2E on milestone boundaries or before final handoff. ## Quality Gate Evidence - This executor owns `quality_gate` emission and branching using [`quality-gate-evidence-template.md`](../workflow-entry/references/quality-gate-evidence-template.md). - Emit canonical fields: `gate_id`, `gate_type`, `trigger`, `criteria`, `result`, `evidence`, `blockers`, `branching`. - Use `gate_type: implementation` for task execution loops. - Normalize local statuses into `result: pass|fail|blocked` before handoff. - If `result: blocked`, emit `[Stop: quality-gate-failed]` and pause for escalation handling. ## Stop/Approval Protocol Use canonical markers: `[Stop: ]`. Classify every stop as `approval_gate` or `escalation_gate`. At each stop, emit a full gate record: `gate_name`, `gate_type`, `trigger`, `ask_method`, `required_user_action`, `resume_if`, `fallback_if_rejected`. Default `ask_method` is `AskUserQuestion`. Resume an `approval_gate` only with explicit user `approved: true`; resume an `escalation_gate` only after user direction or reroute. Respect batch boundary: no autonomous implementation starts before `[Stop: pre-implementation-approval]` is approved. Enforce `max_revision_cycles: 2`; overflow requires human intervention. Agent-local task/review outcomes never replace user approvals. Stop points for this skill: - `[Stop: pre-implementation-approval]` (`approval_gate`) - `[Stop: high-risk-change]` (`approval_gate`) - `[Stop: requirement-change-detected]` (`escalation_gate`) - `[Stop: quality-gate-failed]` (`escalation_gate`) - `[Stop: revision-limit-reached]` (`escalation_gate`) Full protocol and payload schema: [`../workflow-entry/references/stop-approval-section-template.md`](../workflow-entry/references/stop-approval-section-template.md). --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/ssaattww) — claim your Tome and manage your conversions.