v1.22.0

What's changed

Claude Fable 5.1 and Mythos 5.1

Fable 5.1 and limited-access Mythos 5.1 are now available across the shared model catalogue, OpenCode, and Pi. Request normalization, quota routing, server fallback, deterministic recovery, cache warming, and model metadata have been updated for the new models.

Fable 5.1 can also change reasoning effort between turns without moving the cached prefix. OpenCode carries effort transitions through compacted and tool-heavy histories, including downstream message transforms, while Pi rebuilds them from the active compaction-aware branch. The new thinkingBinding.prefixMismatchBehavior setting supports account-default, error, and drop_block for signed-thinking prefix mismatches.

Optional Claustrum custody

OpenCode can opt individual fallback OAuth accounts into local Claustrum credential custody. The request path reads only resident credentials; startup and periodic ticks perform vault I/O, with sidecar credentials retained as the outage fallback. Vault 401 reports are record-version and provenance fenced, custody handles remain confined to the private state file, and /claude-account shows custody status without exposing credentials.

Custody is currently limited to OpenCode fallback OAuth accounts. Main-account and Pi vault serving are not enabled.

OAuth and routing reliability

• Persisted refresh backoffs are bound to refresh-token fingerprints in OpenCode and Pi, so a rotated credential immediately escapes an old invalid_grant latch.
• Claustrum outage fallback uses the same credential-lineage check, and /claude-account reset-backoff clears main refresh and matching quota backoffs explicitly.
• DNS lookup failures use a fixed five-minute OAuth refresh retry interval, including previously persisted long backoffs, while sticky routing can continue using a still-valid fallback token.
• Provider-bound Claustrum tombstones fail locally before OAuth refresh, and shutdown cannot resurrect a transport whose reconnect finishes late.

Compatibility and diagnostics

• Request identity, billing suffix derivation, and final-body cch signing match Claude Code 2.1.258.
• Account-store and request-dump JSON parse errors retain path and location metadata without repeating parser context that may contain secrets.
• Core tests now run in the root quality gate, and OpenCode tests are fenced from live provider endpoints.

Thanks to @iceteaSA for the Fable/Mythos 5.1, Claude Code compatibility, Claustrum custody, parser-redaction, and refresh-recovery contributions.