Claude Code First, specification version 0.1.0. The plain-language guide
Version 0.1.0. Level 3. Best evidence grade R3/S3.
GH-6 A stale copy fails a gate
Where a session can reach more than one copy of a tool or skill that a guard or a gate depends on, a gate SHOULD fail when the copy that answers is stale against its source or is not the intended one.
| Field | Value |
|---|---|
| Keyword | SHOULD |
| Level | 3 |
| Checked | by judgement |
| Findings | F403 |
| Harness facts | none |
| Threat | internal: no failing check is recorded as having held |
| Status | active |
Rationale: in winwright, freewilly and roadkeep's adopters a session ran or read a copy of a shared engine or skill that was stale or not the intended one, and nothing failed (F403, R3/S3). winwright's vendored skill drifted twice; the second time the session-start notice reported it and the agent wrote "I read past it every time" [winwright@a18dd8d], at a counted cost of five refusal round-trips. A notice is therefore shown not to be enough, which points at a check that fails. The finding would admit a MUST, but the one failing check recorded, freewilly's DD118, was deleted with its workflow and did not come back, so no source shows such a gate holding; the rule carries SHOULD until one does.