# Codex Execution Plans (ExecPlans) This file defines how to write and maintain an ExecPlan: a self-contained, living specification that a novice can follow to deliver observable, working behavior in this repository. ## When to Use an ExecPlan - Required for multi-step or multi-file work, new features, refactors, or tasks expected to take more than about an hour. - Optional for trivial fixes (typos, small docs), but if you skip it for a substantial task, state the reason in your response. ## How to Use This File - Authoring: read this file end to end before drafting; start from the skeleton; embed all context (paths, commands, definitions) so no external docs are needed. - Implementing: move directly to the next milestone without asking for next steps; keep the living sections current at every stopping point. - Discussing: record decisions and rationale inside the plan so work can be resumed later using only the ExecPlan. ## Non-Negotiable Requirements - Self-contained and beginner-friendly: define every term; include needed repo knowledge; avoid assuming prior plans or external links. - Living document: revise Progress, Surprises & Discoveries, Decision Log, and Outcomes & Retrospective as work proceeds while keeping the plan self-contained. - Outcome-focused: describe what the user can do after the change and how to see it working; the plan must lead to demonstrably working behavior, not just code edits. - Explicit acceptance: state behaviors, commands, and observable outputs that prove success. ## Formatting Rules - Default envelope is a single fenced code block labeled `md`; do not nest other triple backticks inside—indent commands, transcripts, and diffs instead. - If the file contains only the ExecPlan, omit the enclosing code fence. - Use blank lines after headings; prefer prose over lists. Checklists are permitted only in the Progress section (and are mandatory there). ## Guidelines - Define jargon immediately and tie it to concrete files or commands in this repo. - Anchor on outcomes: acceptance should be phrased as observable behavior; for internal changes, show tests or scenarios that demonstrate the effect. - Specify repository context explicitly: full paths, functions, modules, working directory for commands, and environment assumptions. - Be idempotent and safe: describe retries or rollbacks for risky steps; prefer additive, testable changes. - Validation is required: state exact test commands and expected outputs; include concise evidence (logs, transcripts, diffs) as indented examples. ## Milestones - Tell a story (goal → work → result → proof) for each milestone; keep them narrative rather than bureaucratic. - Each milestone must be independently verifiable and incrementally advance the overall goal. - Milestones are distinct from Progress: milestones explain the plan; Progress tracks real-time execution. ## Living Sections (must be present and maintained) - Progress: checkbox list with timestamps; every pause should update what is done and what remains. - Surprises & Discoveries: unexpected behaviors, performance notes, or bugs with brief evidence. - Decision Log: each decision with rationale and date/author. - Outcomes & Retrospective: what was achieved, remaining gaps, and lessons learned. ## Prototyping and Parallel Paths - Prototypes are encouraged to de-risk changes; keep them additive, clearly labeled, and validated. - Parallel implementations are acceptable when reducing risk; describe how to validate each path and how to retire one safely. ## ExecPlan Skeleton ```md # This ExecPlan is a living document. The sections Progress, Surprises & Discoveries, Decision Log, and Outcomes & Retrospective must stay up to date as work proceeds. If PLANS.md is present in the repo, maintain this document in accordance with it and link back to it by path. ## Purpose / Big Picture Explain the user-visible behavior gained after this change and how to observe it. ## Progress - [x] (2025-10-01 13:00Z) Example completed step. - [ ] Example incomplete step. - [ ] Example partially completed step (completed: X; remaining: Y). ## Surprises & Discoveries - Observation: … Evidence: … ## Decision Log - Decision: … Rationale: … Date/Author: … ## Outcomes & Retrospective Summarize outcomes, gaps, and lessons learned; compare to the original purpose. ## Context and Orientation Describe the current state relevant to this task as if the reader knows nothing. Name key files and modules by full path; define any non-obvious terms. ## Plan of Work Prose description of the sequence of edits and additions. For each edit, name the file and location and what to change. ## Concrete Steps Exact commands to run (with working directory). Include short expected outputs for comparison. ## Validation and Acceptance Behavioral acceptance criteria plus test commands and expected results. ## Idempotence and Recovery How to retry or roll back safely; ensure steps can be rerun without harm. ## Artifacts and Notes Concise transcripts, diffs, or snippets as indented examples. ## Interfaces and Dependencies Prescribe libraries, modules, and function signatures that must exist at the end. Use stable names and paths. ``` ## Revising a Plan - When the scope shifts, rewrite affected sections so the document remains coherent and self-contained. - After significant edits, add a short note at the end explaining what changed and why.