RULESET_NOT_FOUND

No stored ruleset or name binding matches the reference given. HTTP 404. Compile the source again, or load by the name it was saved under.

The ruleset_hash or name you referenced is not in the store this credential can see.

The envelope

{"ok": false,
 "error": {"code": "RULESET_NOT_FOUND",
           "message": "no ruleset with hash 7f3a... in this namespace",
           "docs": "https://docs.agents.jaxon.ai/errors/ruleset-not-found.md"},
 "versions": {"...": "..."}}

Why it happens

The hash was never stored here. A compile stores the source under its hash in the caller's namespace. A hash produced under a different credential, a different connector, or a different deployment is not visible to this one.
A hash remembered from earlier in a conversation has drifted. The model re-typed it, or the source was edited and the hash it now holds belongs to the previous revision that was never saved.
A name that was never bound. dsail_load_ruleset(name) needs a name that dsail_save_ruleset or an approval with name bound. dsail_list_rulesets shows what exists.
The evaluation credential expired. Evaluation credentials expire; the store persists, the visibility does not.

The fix

Have the source? Compile it again — the payload is pure over the bytes, so the same source gives the same hash — or pass source to the check directly instead of a hash.
Saved under a name? Load it by name and use the ruleset_hash the load returns, byte-for-byte.
Need to share a ruleset across credentials? A full credential can be bound to the connector's namespace by Jaxon.