Errors & status

Two frame types tell you when something about a subscription changes or a request fails: status for subscription state transitions, and error for rejected requests and failed subscriptions.

`status`

{ "type": "status", "v": 1, "serverTimestamp": 1748020034300, "subscriptionId": "f47ac10b-…", "state": "resyncing", "reason": "connectDown" }

state is one of:

`state`	Meaning
`live`	Streaming normally.
`resyncing`	A gap or upstream reconnect occurred. Drop your local book; a fresh `snapshot` follows. (On the trade channel there is nothing to rebuild.)
`closed`	The market settled / resolved. No more data.
`unsupported`	This market or side isn’t supported for streaming.
`unavailable`	The market couldn’t be streamed (terminal).

reason is an optional machine-readable hint. When one market-level event affects several subscriptions on your connection, you get one status frame per affected subscriptionId.

`error`

{ "type": "error", "v": 1, "serverTimestamp": 1748020034220, "market": { "venue": "polymarket", "outcomeId": "bad" }, "channel": "book", "code": "UNKNOWN_MARKET", "message": "…" }

The addressing fields tell you what the error is about:

Active-subscription error — carries subscriptionId.
Subscription-creation error — carries market + channel (the subscription was never created, so there’s no id).
Connection-level error — neither; just code, message, and the requestId you sent.

Error codes

Error codes are SCREAMING_SNAKE_CASE (distinct from the lowercase status state values above). Retryable says whether resending the same request can ever succeed. No means resending is pointless — change the request, free up capacity, or stop. It does not always mean the situation is permanent, so the cell says which.

`code`	Retryable	Meaning
`UNKNOWN_MARKET`	No	The `MarketStream` didn’t resolve to a real market. Also returned for a Kalshi subscribe naming the unsupported `no` side — a Kalshi ticker addresses a single YES-priced book, so that request is refused permanently; subscribe with side `yes` or omit it. On that refusal the frame is connection-level: it carries `code`, `message` and your `requestId`, with no `market` and no `channel`. The socket stays open.
`QUOTA_EXCEEDED`	No — retrying alone won’t help	You hit the per-connection subscription cap. Unsubscribe something you no longer need, or open another connection; the same subscribe then succeeds.
`NOT_AUTHORIZED`	No	Not authorized for this operation.
`UNSUPPORTED_CHANNEL`	No	The requested channel isn’t available on this market’s venue. Returned for a `trade` subscribe on a venue that publishes no public trade tape — currently Limitless. The error carries `market` + `channel`; no subscription is created and other entries in the same batch are unaffected.
`SERVICE_DEGRADED`	Yes, with backoff	The service is temporarily degraded (e.g. an upstream link is down). Retry shortly.
`SNAPSHOT_TIMEOUT`	—	Reserved, and not currently emitted. A subscribe whose first snapshot never arrives is reported as `UNAVAILABLE`. Handle the code if you switch on the enum exhaustively, but don’t build retry behaviour around it.
`UNAVAILABLE`	Yes, after a delay	The market can’t be streamed right now — the first snapshot didn’t arrive, or an upstream venue read failed after retries. Your subscription is torn down, so this is terminal for that subscription, but the condition is usually transient: resubscribe after a short delay rather than immediately, and treat repeated failures for one market as that market being unavailable for now.
`INTERNAL`	Only for server faults	An unexpected server-side fault, or a frame that failed validation. If your client always builds the frame the same way it will keep failing, so don’t retry blindly: retry once or twice with backoff to rule out a transient fault, and if it persists inspect the frame you sent before retrying further. Contact support if the frame is correct.

The message on the Kalshi no-side refusal is:

the ‘no’ side isn’t supported for streaming: a Kalshi ticker addresses one YES-priced book, so subscribe with side ‘yes’ or omit it.

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Market data

Reference

Errors & status

`status`

`error`

Error codes

​status

​error

​Error codes

`status`

`error`

Error codes