# AGENTS.md — working rules for coding agents on RustyRPN

readme.md is the single source of truth for design decisions and roadmap.
Read at minimum these sections before starting work:

- §Workflow — the TDD loop you are expected to follow
- §General guidelines for AI — hard prohibitions
- §Data formats — input formats, edge cases, and where test fixtures live
- §Roadmap and status of functionality — what is green, red, or unstarted

## Environment

- Rust stable (edition 2024, MSRV 1.85) via rustup; on this machine the
  shims are at `/opt/homebrew/opt/rustup/bin` (in PATH via ~/.zprofile).
- All cargo commands run from `Application/`:
  `cargo test`, `cargo fmt --check`, `cargo clippy`.
- Workspace members: `src/core` (rpn-core, domain logic),
  `src/cli` (rpn-cli, binary `rpnc`). `src/server` and `src/web` are
  planned but not scaffolded yet.

## Current state (verify against readme.md roadmap; update both when it changes)

- core/config: implemented, tests green.
- core/db: tests committed and RED (they reference functions that do not
  exist yet — the crate does not compile its test target). The first task
  is the minimal implementation to turn them green. Do not weaken or
  rewrite these tests to make them pass; they encode agreed behaviour.
- cli: `fn main() {}`. Command surface specified in Documentation/cli.md.
- feature/epsilon-parser: branch exists, zero commits. Needs workflow
  step 2 (spec + test checklist agreed with the maintainer) before any
  failing test is written.

## Test data

- Real samples: `Application/data/test_input/` — gitignored, never
  committed, never embed their values in test files or fixtures output.
- Committed sanitized fixtures: `Application/data/fixtures/`
  (epsilon / tsdrms / subfranchise). Parser tests should use these.
  Regenerate with `python3 Application/scripts/sanitize_samples.py`;
  after any change to fixtures run
  `python3 Application/scripts/check_fixture_leaks.py` and require exit 0.
- `Documentation/schema.sql` is the v1 domain schema; it is also the
  embedded migration (test-asserted in core/db).

## Git rules

- Work on a named feature branch; commit per passing test (workflow step
  5.3). Commit messages are the project's code documentation: format
  `area: imperative summary`, body explaining *why*.
- Never commit or push to `main` without the maintainer's explicit
  approval. Never rewrite history.
- Never commit: config files (except config.template.toml), anything under
  data/ except data/fixtures/, secrets, real customer data.

## Definition of done for a task

1. `cargo test` green (all crates), `cargo fmt --check` and
   `cargo clippy` clean for files you touched.
2. Every checklist item from the task's spec verified — by a test or by
   a command you actually ran, not by inspection alone.
3. readme.md roadmap updated in the same branch.
4. A short summary for the maintainer: what changed, what is still red,
   suggested next step.