/policy-algebra
Generates frozen, drift-checkable governance rules from thin intent strings (deep interview) or rich plan inputs (shallow confirmation). Produces fenced Starlark blocks callers can inject into downstream work, and exposes
--verify
for canonicalized drift detection.
Invocation
/policy-algebra ``starlark
<raw frozen starlark block, as /review approved>
REVIEW_ROUNDS:
PANEL:
STATUS: CONVERGED
FILE: (only when --write was used)
NOTE: (optional)
If--write was supplied, write the raw Starlark block to that path and includeFILE:
--verify flow
- Read both files.
- Extract first
```starlarkfenced block from each file. - Normalize both blocks (strip trailing whitespace, collapse blank lines, trim edges).
- If equal → print
MATCH, exit 0. Else → printDRIFT+ unified diff, exit 1. Use the following bash to verify drift — no external dependencies needed: ```bash
policy-algebra verify — inline, no dependencies
Usage: bash verify.sh
- normalize()
- extract_starlark() { sed -n '/^
starlark/,/^$/p' "$1" | sed '1d;$d'; } - FROZEN=$(extract_starlark "$1" | normalize)
- CANDIDATE=$(extract_starlark "$2" | normalize)
- if [ "$FROZEN" = "$CANDIDATE" ]; then
- echo "MATCH"
- exit 0
- else
- echo "DRIFT"
- diff <(echo "$FROZEN") <(echo "$CANDIDATE")
- exit 1
- fi
- Multiple-block behavior
- When a file contains multiple
- ```starlark
- blocks,
- extractAlgebra
- silently uses the first. This is intentional — wrap your canonical rules in the first fenced block of any document.
- Failure modes
- Failure
- Behavior
- Target omitted
- Error: "target required"
- SHALLOW: file unreadable
- Fall through to DEEP with path string as intent
- SHALLOW: < 2 extractable invariants
- Fall through to DEEP with file contents as intent
- DEEP:
- /grill-me
- unavailable
- Error: "deep interview requires /grill-me skill"
- DEEP: user abandons interview
- Inherit
- /grill-me
- 's exit behavior
- Drafting produces empty Starlark
- Error: "no invariants found to codify"; return invariant list
- /review
- caps without convergence
- Inherit
- /review
- escalation — no custom handling
- --write
- unwritable
- Error with path; return inline result anyway
- Either
- --verify
- path unreadable
- Error with path, exit 2
- No
- ```starlark
- block
- NoAlgebraBlockError
- with path, exit 2
- canonicalize
- throws
- Error with stack, exit 3
- Exit codes
- Code
- Meaning
- 0
- MATCH (verify) / SUCCESS (normal)
- 1
- DRIFT (verify only)
- 2
- Input error (missing file, bad args,
- NoAlgebraBlockError
- )
- 3
- Internal error
- Cross-tool notes
- Claude Code
-
- invokes
- /grill-me
- (DEEP interview) and
- /review
- (panel convergence) via the
- Skill
- tool. Both exist as project-local
- skills under
- .claude/skills/
- .
- Codex / Cursor
- the Skill tool is Claude-Code-only. Read the relevant skill files directly: .claude/skills/grill-me/SKILL.md — for the interview procedure .claude/skills/review/SKILL.md — for panel convergence Apply their procedures inline rather than invoking them as commands. The drafting, freeze, and --verify logic in this SKILL.md is tool-agnostic and works identically for Claude Code, Codex, and Cursor. CLI ( --verify path) is runtime-agnostic: use the inline bash snippet in the --verify section above — no Node or pnpm required. Governance This skill is self-hosted: its own rules are encoded as a frozen Starlark governance block. Drift from these invariants is a bug. Verify with /policy-algebra --verify .
policy-algebra governance — self-hosted
FROZEN — do not edit; regenerate via /policy-algebra
DEFAULTS = { "min_invariants": 2, "exit_codes": {"match": 0, "drift": 1, "input_error": 2, "internal_error": 3}, "required_output_fields": ["ALGEBRA", "REVIEW_ROUNDS", "PANEL", "STATUS"], "converged_status": "CONVERGED", }
SELECT_MODE: file path → SHALLOW; intent string → DEEP.
def SELECT_MODE(target): if is_readable_file(target): return "SHALLOW" return "DEEP"
SHALLOW_OR_DEEP: fall through to DEEP when extraction yields < min_invariants or is ambiguous.
def SHALLOW_OR_DEEP(invariants, ambiguous): if len(invariants) < DEFAULTS["min_invariants"] or ambiguous: return "DEEP" return "SHALLOW"
EXTRACT_BLOCK: use first starlark fence only; multiple blocks → first wins.
def EXTRACT_BLOCK(fences): if len(fences) == 0: return None return fences[0]
OUTPUT_VALID: output must carry all required fields; STATUS=CONVERGED only after review.
def OUTPUT_VALID(output, review_loop_passed): fields_present = all([f in output for f in DEFAULTS["required_output_fields"]]) converged_ok = output.get("STATUS") != DEFAULTS["converged_status"] or review_loop_passed return fields_present and converged_ok
VERIFY: canonicalize both blocks and compare; never modify source files.
def VERIFY(frozen_canon, candidate_canon): if frozen_canon == candidate_canon: return DEFAULTS["exit_codes"]["match"] return DEFAULTS["exit_codes"]["drift"]
EXIT_CODE: map outcome strings to numeric codes.
def EXIT_CODE(outcome): return DEFAULTS["exit_codes"].get(outcome, DEFAULTS["exit_codes"]["internal_error"])