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REST API for the Ostium Builder SDK and integrating partners: live prices, depth, OHLC, and market hours.

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Authentication

None required today.

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Quick start

  1. Snapshot — GET /v1/prices (or GET /v1/prices/{pair}) for an initial board.
  2. Stream — connect to WS /v1/prices/stream for live ticks — see the Price Stream section.
  3. Candles — POST /v1/ohlc for historical OHLC.
  4. Sessions — GET /v1/market-hours for calendars (cache it; use tick flags for “open right now”). The pair list is under Markets.
  5. Depth — GET /v1/depth/{pair}/quote for the price a given size actually gets.
  6. Status — GET /v1/status to check the price feed is live before relying on quotes.
Typed clients: use @ostium/builder-sdk, or generate one from this document with any OpenAPI 3.1 client generator.

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Rate limits

Applied per IP. Most limits are per route; where a group of endpoints shares one budget the endpoint’s own description says so. Every rate-limited response carries x-ratelimit-limit, x-ratelimit-remaining, and x-ratelimit-reset; 429s add retry-after. Read the headers — do not hard-code the documented figures.

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Errors

Two envelopes:
  • Framework — { "error": "<Status Name>", "message": "..." } (optional issues / details).
  • Upstream proxy — { "error": "<human message>" } from OHLC failures.
error means different things across the two shapes — do not switch on it alone until a future major version unifies them. Every response carries x-request-id. Quote it when reporting a problem.

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Hosts

Each chain is served by exactly one host, because an environment’s oracle publishers are only registered against its own chain’s verifier. Sending a chain to the other host is refused with a 400 naming the one that works.
  • Production (Arbitrum One, chainId 42161): https://builder.prod.bedrock.ostium.io
  • Staging (Arbitrum Sepolia, chainId 421614): https://builder.stage.bedrock.ostium.io
Read endpoints — /v1/pairs, /v1/trades, /v1/prices, depth — have no publisher dependency and serve both chains from either host. Only /v1/orders is pinned.