Errors and conventions

Conventions

Prices and money are decimal strings in USD, such as "0.4100", never floats. A price is per contract that pays $1.
Times are RFC 3339 in UTC.
Responses wrap results in data. Graph-derived responses also name the graph_run they were read from; runs finish hourly.
Pagination returns next_cursor when more results exist. Pass it back as cursor unchanged.
Unknown or repeated query parameters are rejected with 400, so a typo never silently widens a query.

Errors return {"error": {"code": "...", "message": "..."}}. Branch on code; messages may change.

Status	Code	Meaning
400	`invalid_parameter`	A query parameter is unknown, repeated or out of range.
400	`invalid_market`	The venue is not `kalshi` or `polymarket`, or the market id is malformed.
401	`api_key_required`	No key was sent.
401	`invalid_api_key`	The key is malformed or unknown.
401	`api_key_revoked`	The key was revoked.
404	`market_not_found`	The market is not in the latest graph.
404	`not_found`	No such endpoint.
429	`rate_limited`	The per-minute limit was exceeded.
429	`daily_quota_exceeded`	The daily quota is used up.
503	`graph_unavailable`	No graph run has finished yet.
504	`timeout`	The request took longer than 15 seconds.
500	`internal`	Something failed on our side.