Codex and Claude already emit credential-level quota watermarks on ordinary responses. CPA used to drop them. Keep the latest watermark in memory and return it from the management auth-file API. Hard rule: this is observation only. It must not change scheduling, cooldown selection, or auth-file persistence. Snapshot, not accumulation - QuotaState now has ObservedAt and a bounded Signals map. MarkResult fills them from the response headers already recorded on the request. - Signals is the current response, not a union of earlier ones. Retry-After and "limit reached" only appear on the response that produced them; merging across responses would keep an expired value forever. - A response with no quota header (transport failure, 5xx, unrelated endpoint) leaves the previous snapshot in place. - ObservedAt is the time of the current snapshot. It advances even when the values did not change, so a consumer can tell a fresh reading from a stale one. - When two model states merge, keep the newer snapshot. Do not union keys captured at different times. What is observed, and what is not - One predicate, ProviderSupportsQuotaObservation, decides the provider set. - Keep Codex and Claude. Drop Kimi, xAI/Grok, Antigravity, and the Gemini family (gemini/vertex/aistudio): their ordinary headers are not a reliable credential-level remaining quota. - Count-tokens reuses the credential but is not generation traffic. ExecuteCount sets SkipQuotaObservation so those headers cannot replace the last generation snapshot. Cooldown and success/failure accounting still run. Cooldown must not overwrite the last snapshot - Observation writes only ObservedAt and Signals. - Cooldown writes only Exceeded, Reason, NextRecoverAt, and BackoffLevel, through applyCooldownFields. Never assign a fresh QuotaState{...} over a live value: that would zero the snapshot on 429, Cloudflare, credential- scope sibling updates, and cooldown clears. - If a credential-quota cooldown is still active, MarkResult still observes an already-present model state. It does not create scheduler state just to record a watermark. - .cds files persist cooldownFieldsOf(Quota) only. Restore keeps the newer ObservedAt, so reloading cooldown cannot clobber a newer in-memory snapshot. - cooldownQuotaEqual still ignores observation fields, so a watermark change cannot by itself persist cooldown or move the scheduler. - The management payload omits every cooldown field, so it cannot be mistaken for scheduler state or wired back into scheduling. - Manual ResetQuota still clears the full QuotaState. Codex websocket events - Codex WS reports quota as codex.rate_limits frames, not HTTP headers. ParseCodexQuotaEventHeaders turns one event into the same bounded header shape, and MergeResponseHeaders folds it into the request-scoped holder. additional_rate_limits is accepted as an object (websocket) or an array (/wham/usage). - Parse only through AppendCodexAPIWebsocketResponse. The shared AppendAPIWebsocketResponse is also used by xAI, and xAI error frames really do carry x-ratelimit-* headers. Parsing every frame as Codex quota would forge Codex headers into another provider's request log. - Also capture code_review_rate_limits. - A malformed active-limit name drops only that one header, not the window watermarks parsed from the same event. - The type discriminator scans a bounded frame prefix, not every byte of every frame. - HTTP namespaces an extra limit by short name (x-codex-bengalfox-*); WS namespaces it by limit name (GPT-5.3-Codex-Spark). The two paths cannot emit the same header names. The X-Codex-Additional- prefix marks the WS origin, and snapshot replacement keeps the two spellings from piling up. Hardening - Reject observed values with control characters. These strings reach the plain-text request log, and Limit-Name is upstream-controlled, so CR/LF could forge a header line. - When the header cap is hit, keep plan/credits/primary ahead of additional-limit namespaces, then sort names so truncation is deterministic. - QuotaState.Clone deep-copies Signals and is used by Auth.Clone and ModelState.Clone. - Token stores still serialize credential metadata only, so observation adds no auth-file writes.