OpenAI/Composite groups can now reject requests that exceed the max
reasoning effort instead of always rewriting them down to the ceiling.
Existing groups keep the previous auto-downgrade behavior.
- Accept fast|priority (canonical priority), flex|auto|default|scale on
/v1/responses and /v1/chat/completions; reject unknown/empty/non-string
with HTTP 400; omitted and null stay compatible.
- Propagate service_tier through JSON/SSE, Responses<->Chat conversions,
fallback paths and HTTP->upstream WebSocket bridge.
- Billing prefers the upstream terminal tier; the outbound (policy-
transformed) tier is used only when upstream omits the field.
Explicit upstream default bills Standard even when Fast was requested.
- Pricing: Fast premium 2x Standard for gpt-5.6-sol/terra/luna and
gpt-5.4; 2.5x for gpt-5.5; channel FastMultiplier stays authoritative.
- Live verification (official Codex 0.149.0 + gateway, HTTP & WS):
upstream ChatGPT backend may return terminal default even when the
account catalog advertises priority; billing follows the actual tier.
sanitizeGroupMessagesDispatchFields forces AllowMessagesDispatch=false for
every non-openai platform including composite, and the gate checked only the
group platform — so composite requests resolved to grok/CN targets were
rejected 403 on /v1/messages and /v1/messages/count_tokens before reaching
the composite target whitelist, leaving the CN rollout unusable for
Claude-protocol clients.
- allowOpenAICompatibleMessagesDispatch: composite groups resolved to a
grok/CN target get the same exemption as the standalone platforms;
openai-resolved and unresolved targets keep requiring the switch
- resolveOpenAIMessagesDispatchMappedModel: skip the group-level dispatch
model mapping (openai-specific gpt defaults) for composite grok/CN
targets — model rewriting stays with account-level model_mapping
- Responses WebSocket composite whitelist stays openai+grok: CN accounts
cannot pass the WSv2 ingress transport filter and the WS HTTP bridge
has no Responses conversion for them, so admitting CN targets only
turns a clear policy rejection into a misleading no-available-account
- widen the responses/input_tokens and messages/count_tokens composite
gates to the shared openai-compatible text whitelist so CN targets get
the same local-estimate token counting as generation
- restore the Claude default-model fallback for standalone CN groups
(admin candidates and custom models list) while keeping composite
listings limited to CN account mapping keys
- refresh the scheduler bulk-rebuild comment and bucket capacity hints
for the 8-platform canonical set
OpenAI sunset the legacy unary /responses/compact endpoint (404, #5598,
#5624), so the account "compact probe" in the admin UI kept failing even for
healthy accounts, and the beta-feature negotiation header was only attached
to compaction turns.
Beta features (codex-rs session/mod.rs build_model_client_beta_features_header
+ client.rs build_responses_headers): the header is a session-level constant
attached to every /responses request, the WS handshake and /responses/compact.
Enumerating FEATURES shows no Experimental feature is enabled by default, so a
default install sends exactly "remote_compaction_v2". Mirror that:
- OAuth requests without a client-declared header get the default shape, so we
no longer produce a "header only on compaction turns" pattern real Codex
never emits (#5586 chains that strip the header)
- a client-declared header is preserved as-is: non-empty without v2 means the
user disabled the feature and the gateway must not rewrite that
- native v2 turns (compaction_trigger in body) always ensure v2 is present
- non-OAuth upstreams keep the compaction-turn-only behaviour
- the WS injection sits outside the client-header copy block so prewarm and
turn handshakes cannot land in different pool compatibility buckets
Compact probe now exercises native v2 (streaming /responses +
compaction_trigger) instead of the dead endpoint. Success requires an actual
compaction output item — scanning output_item.done/added, the terminal
response.output[] and the whole-JSON fallback — so a 2xx that silently drops
the trigger is reported as unsupported (the "got 0 items" class, #5478,
#5648). Probe identity is now UUID-shaped and applies the account's
convergence, matching real traffic on the same endpoint.
When OpenAI Responses streaming has compact keepalive commit 200 headers
but no semantic SSE event has been written, upstream 4xx errors were
silently swallowed, causing clients to hang until timeout.
The fix distinguishes between 'headers committed' and 'meaningful SSE
output written'. Compact keepalive may commit headers for heartbeat
purposes without writing actual SSE events. In that case, the Responses
stream still needs its protocol-correct terminal response.failed event.
Preserves existing behavior when a complete upstream response or
meaningful SSE payload was already communicated, and preserves image
keepalive semantics.
Fixes#5289
Wesley Liddick