# os-context

Prompt-composer `SessionStart` plugin (renamed 2026-07-13 from os-orchestration):
concatenates `prompts/session-start/*.md` into one `additionalContext` block,
injected at session start and after compaction/resume.

## Component map

- `prompts/session-start/` — 4 files, concatenated in filename order:
  `10-orchestration.md` (session-orchestration + delegation-economics rules — do
  not edit without explicit approval, per eval-wording sensitivity),
  `20-kickoff-conventions.md`, `30-standing-safety.md`, `40-decision-memos.md`.
- `hooks/inject.py` — the composer; enforces the line-budget guard (120/240).
- `hooks/hooks.json` — SessionStart wiring, matcher `startup|resume|clear|compact`.
- `skills/audit-sessions/SKILL.md` — `/os-context:audit-sessions`, the biweekly
  orchestration IRL audit against `10-orchestration.md`'s shipped rules; see
  `skills/audit-sessions/references/rubric.md`.
- `audit/bin/{audit-stats,extract}` — deterministic driver scripts the audit
  skill calls; skill-local, not a plugin-root `bin/`.
- `tests/hook_test.py` — unittest, covers compose order + budget logic.
- `eval/` — Eval harness (prompted grid, scenarios + `scenarios-reserve/`); eval
  discipline (reserves never read informally) per root `CLAUDE.md`.

## Pointers

- Decision: [docs/adr/0031](../../docs/adr/0031-os-context-prompt-composer-plugin-supersedes-single-file-os-orchestration.md)
  (prompt-composer plugin, supersedes the single-file os-orchestration approach).
- Status/build history: `docs/implementation-status/os-context.md`.