Validate

Independently judge one exact subject against the acceptance in its existing bead or caller source, return one semantic result, and stop. Validate is the sole verdict.v2 writer when persistence is requested. It never asks the model to reconstruct Plan or Candidate packets.

Preconditions

• The subject is a nonempty implementation candidate: the manifest lists at least one entry, and store-verdict refuses an empty one. Plans, audits, reviews, and other control artifacts are not completion subjects unless the caller explicitly requested document review.
• The intent source is available as a caller-owned artifact or runtime-owned content-addressed snapshot; its acceptance digest is derived automatically.
• The subject manifest still matches the subject.
• Author and validator context IDs are explicit.
• Freshness is explicitly attested with source: runtime | caller and an attester identity.

Missing, colliding, or unattested identities produce NOT_PROVEN. This is a declared trust fact, not cryptographic proof that contexts were isolated.

Cross-model fresh validator (caller-elected)

A caller may request that the fresh validator run on a different model than the author. Dispatch via the controller-session recipe in the agent-native model-dispatch recipe (codex-exec and/or ntm, probed at runtime). Record author and validator model_identity in evidence refs and freshness attestation notes — do not change verdict.v2 schema. If the requested validator model has no live adapter, disclose the unsatisfied diversity request and proceed same-model; never invoke claude -p / claude --print. Single fresh validator remains the default shape.

Mutating-check quarantine

Before running any acceptance-listed command, classify it as read-only or subject-mutating. Regen scripts, sync scripts, formatters, and anything with --force are subject-mutating until proven otherwise. Never run a subject-mutating check against an uncommitted subject: on 2026-07-15, scripts/test-ci-deterministic-gates.sh regenerated skills-codex/ from HEAD mid-validation and destroyed the uncommitted subject, forcing NOT_PROVEN (verdict b6e759dd...cb6a); only restoring the subject and revalidating in a fresh context produced the PASS (e9b6cdb8...37b9). If a mutating check is genuinely required by acceptance, run it against a disposable copy or a committed subject, never the judged working tree.

Scope disclosure

not_checked has exactly one meaning: in-scope acceptance surface this validation did not verify. PASS asserts that the whole declared acceptance surface was verified, so a PASS carries no not_checked entries; the helper refuses one and records a validate.integrity finding.

That rule never pays for deleting an honest caveat, because every kind of scope limit has a home that survives inside a PASS:

Emptying not_checked to obtain PASS is a contract violation, not a workaround. If acceptance really went unverified, the honest result is NOT_PROVEN. If the entry was never acceptance in the first place, it belongs in one of the other homes, where it stays visible in the stored artifact instead of being deleted.

Helper commands

The helper ships beside this file. Invoke it through this skill's own directory rather than a checkout-relative path: $SKILL_DIR is the directory containing this SKILL.md — skills/validate/ in a repository checkout, .agents/skills/validate/ in an installed runtime.

python3 "$SKILL_DIR/scripts/validate.py" manifest \
  --root . --include skills/validate --exclude '**/*.log' --output manifest.json

Workflow

1. Recompute and compare subject-manifest.v1 with the manifest command above (--root plus at least one --include). The helper uses only filesystem content; Git commit/tree IDs are optional metadata. Derive the manifest at the start of validation and re-derive it at the end; any mismatch between the two is subject mutation and returns NOT_PROVEN.
2. Confirm the intent-source digest has not changed since implementation. If the subject changed or complete changed-path coverage cannot be derived, return NOT_PROVEN.
3. Adjudicate the actual diff, not a declared path list: compare runtime-derived actual changed paths against the intent's scope classes. A proven out-of-scope path returns FAIL; incomplete scope evidence returns NOT_PROVEN.
4. Inspect the exact subject and factual evidence. Reported exit codes are claims, not evidence: re-execute the claimed proofs that bear on acceptance (see the freshness rules below for when a digest-bound receipt suffices). If the subject changes a test, gate, fixture, golden, tolerance, suppression, or acceptance source, determine whether the original intent requires that change and whether green came from implemented behavior rather than a weakened oracle. Green obtained by weakening acceptance is FAIL, not evidence of completion. Judge every acceptance criterion and record criterion-level results, findings, evidence references, checked, and any acceptance surface that went unverified in not_checked (see Scope disclosure).
5. Choose exactly one semantic result: PASS, FAIL, or NOT_PROVEN. Return it with criterion results, findings, evidence references, checked, not_checked, the acceptance and subject identities, distinct author and validator context IDs, and the freshness attestation. PASS requires distinct identities, explicit freshness, nonempty checked scope, top-level evidence, evidence for every criterion, and an empty not_checked; route bounded proofs, declared non-goals, and residual risk to the homes named in Scope disclosure rather than deleting them or downgrading a proven result.
6. Only when the caller requests machine-readable evidence or a declared downstream consumer requires it, persist canonical verdict.v2 with the helper's store-verdict --draft <draft.json> --intent-source <resolved-intent> --subject-manifest <manifest.json> --author-context-id <id> --validator-context-id <id> --freshness-source <runtime|caller> --freshness-attester-id <id> --scope-result <PASS|FAIL|NOT_PROVEN>. The helper snapshots the exact resolved intent under <workspace>/.agents/ao/intents/sha256/<digest>.intent, then computes and injects intent and subject digests plus author, validator, and freshness facts. Identity and changed-path facts come from runtime-derived inputs and receipts, not model transcription. Storage defaults to <workspace>/.agents/ao/verdicts/sha256/<digest>.json; callers may provide verdict_dir.
7. Return the semantic result and, when persisted, the artifact path and digest. Stop.

The digest is SHA-256 over canonical JSON with artifact_digest omitted. Writes use a same-directory temporary file, flush, fsync, and atomic rename. Identical existing content is idempotent success; conflicting content is an integrity failure represented by NOT_PROVEN.

Freshness without duplication

Fresh validation means independent judgment over the exact subject. It does not require mechanically replaying every author command. Verify intent identity, scope, evidence digests, and every acceptance criterion; independently rerun the risk-critical, uncertain, or insufficiently evidenced checks. A digest-bound deterministic receipt may prove routine facts. Replay an expensive full suite only when acceptance requires that result or the supplied receipt cannot establish it.

Boundary

Validate emits no WARN, confidence, disposition, briefing learning, owner, next action, repair, retry, replan, helper, escalation, tracker, Git, release, closure, or delivery state. Generic provenance may record a verdict later, but ledger availability cannot change its validity.