Commit Gate Core

commit-gate-core on this branch is unreleased v0.2.0 prepare: an authorize-only kernel. It hashes caller-supplied payload_bytes inside the gate and checks the bound DecisionRecord for verdict, scope, policy version, time window, verifier result and nonce freshness. It returns authorisation or refusal; it does not apply the payload or invoke mutation_callback.

GitHub Latest is still v0.1.1. That tag can invoke mutation_callback. This tree is not Latest until a separate B2 ticket tags v0.2.0 and /releases/latest resolves to that tag.

Release boundary

Object	Status	Behaviour
v0.1.1	Latest tagged release	Historical predecessor. CommitGate.execute can invoke a caller-supplied mutation callback. It is not the authorize-only kernel described below.
main / this branch / 0.2.0	Unreleased prepare	Binds exact payload bytes and returns authorisation or refusal. It never applies the payload. Not Latest.

The authorize-only successor entered main in merge commit c0fbc5f. GitHub's Latest badge therefore identifies the latest release, not the function currently present on this tree.

Research map: https://lalaskye.github.io/inspection-surface/

Canonical message format: docs/governance/CANONICAL_BYTES_AND_ED25519_V1.md

1. What the authorize-only kernel is

A small Python gate that authorises a DecisionRecord against a payload. It hashes the caller-supplied payload_bytes inside the gate, checks scope, time window, policy version, and nonce, then returns AUTHORIZED or a deny/error code.

It checks the configured verifier. The demonstrated tests use an HMAC-SHA256 lab MAC.

It does not apply the payload. mutation_callback is never invoked. execute is a deprecated wrapper: it requires payload_bytes and only calls authorize. A commit_hash with no payload is refused (DENY:COMMIT_HASH_ONLY_FORBIDDEN).

Ed25519 is specified for a later extra. It is not implemented in this tree.

2. What it refuses

On the demonstrated path the gate refuses when:

• there is no record
• required fields are missing or empty
• verdict is not ALLOW
• policy version is not accepted
• the configured verifier does not accept the record
• the record is not yet valid or has expired
• actor, action, object, environment, or payload hash do not match
• the nonce was already consumed
• payload_bytes is omitted
• only a caller-supplied commit_hash is offered
• the authorised audit event cannot be written; authorisation is refused and nonce rollback is attempted. Rollback failure has a separate error code.

Two-phase apply lives under experimental/ and is not a public export.

3. One local command

From a clone of this tree:

PYTHONPATH=src python -m pytest tests/test_authorize.py tests/test_beau_failure_classes.py -q

Expected: those files pass. They prove authorise-without-mutate, hash-only refusal, payload binding inside authorize, and audit-failure rollback with the in-memory test ledger.

Do not install or cite v0.1.1 as evidence of the authorize-only kernel.

Install-from-tag until B2:

python -m pip install "commit-gate-core @ git+https://github.com/LalaSkye/commit-gate-core.git@v0.1.1"

That command installs the historical Latest object, not this kernel.

4. What it does not claim

This object does not claim production readiness, enterprise deployment, compliance, certification, path-universal enforcement, crash-safe durable nonces, atomic PREPARED+nonce persistence, or that consequence cannot occur outside this process.

It does not claim that Ed25519 is implemented. It does not claim certificates or algorithm agility. It does not claim that the lab MAC is a signature. It does not claim that start-here is this kernel. It does not claim that GitHub Latest is this tree.

Working paper (broader than this package): https://doi.org/10.5281/zenodo.19980275

License

MIT.