syngen-implement-feature

name	syngen-implement-feature
description	Use for implementing production-grade Syngen features or non-trivial code changes.

Syngen Feature Implementation

Vocabulary

Use the names defined in docs/agent-harness/glossary.md (business / product, plus the metadata-YAML keys). If a draft uses an undefined term, add it to the glossary in the same change rather than inventing a synonym.

Workflow

0. Bootstrap check. If pytest fails to collect or any python -m … command reports ModuleNotFoundError, invoke the syngen-bootstrap skill before continuing. The harness fixed a structural collection break on 2026-05-27 by adding src/tests/__init__.py and a [tool.pytest.ini_options] block in pyproject.toml; runtime deps from requirements.txt may still be missing locally.
1. Frame the change. Restate the requested change and identify affected workflows: [[training run]], [[inference run]], [[metadata YAML]], [[reports]].
2. Research. Inspect relevant source under src/syngen/, tests under src/tests/unit/, examples in examples/, demo notebooks, CI configuration.
3. Identify public-surface impact. [[CLI entry points]] (train, infer, syngen — note these are the binary names; launch_train / launch_infer are the function names), [[SDK]] (Syngen class in src/syngen/sdk.py), [[metadata YAML]] schema, or serialization format. Any break is an [[escalation trigger]].
4. Downstream impact. Every public-surface change propagates to [[tdm_syngen]] (enterprise edition) and external PyPI users. Flag and escalate per CLAUDE.md "Approval contract" before implementing.
5. Plan. Draft a minimal implementation plan listing files to touch, schemas/models to add or update, tests to add (src/tests/unit/, plus integration tests if CLI / file I/O / metadata execution is affected).
6. Implement. Smallest viable change aligned with existing patterns in syngen.ml.
7. Version bump. Update src/syngen/VERSION — semver patch by default; minor when public API or CLI changes; major requires APPROVAL REQUIRED: and explicit approved per the contract.
8. Test. Per testing-contract.md:
   • Unit test for every new branch / validator rule.
   • Positive and negative [[validation schema]] tests for every marshmallow schema change.
   • [[Regression test]] for every bug fix.
9. Validate locally, all from the repo root (cd "$(git rev-parse --show-toplevel)"):

   PY="${REPO_ROOT}/.venv/bin/python"; test -x "${PY}" || PY="$(command -v python)"
   "${PY}" -m pytest src/tests/unit/<touched_subpath> -q
   "${PY}" -m flake8 --max-line-length 99 src/syngen/<touched_subpath>
   "${PY}" -m pytest src/tests/unit/ -q          # full unit suite before handoff
   

   If any reports ModuleNotFoundError, run syngen-bootstrap once and retry.
10. Subagents. Invoke syngen-code-reviewer for non-trivial code changes; syngen-test-engineer if test coverage needs review; syngen-security-reviewer for any change touching encryption, credentials, data flow, or logging.
11. Handoff. State: changed files, tests run, lint results, downstream-impact assessment, documentation updated (glossary, README, examples).