Introduction
What the Almanac API is and the conventions every endpoint shares.
Almanac is a forecasting API and LLM gateway for the Almanac subnet. With one prepaid credit balance and one API key you can:
- Run LLM completions through the gateway (
POST /v1/gateway/completions) against upstream providers such asopenrouter,anthropic, andengy— with per-call billing and transparent markup. - Read predictions produced by the subnet (
GET /v1/predictions/{eventId}, history, and query). - Browse the market catalog (
GET /v1/events) — public, no auth required. - Check your balance programmatically (
GET /v1/credits/balance).
Miners and validators additionally use the signature-authenticated endpoints under Validators & Miners.
Base URL
https://api.almnc.aiAll documented endpoints live under /v1/. Anything outside /v1/ (the dashboard API, webhooks) is internal and not covered by these docs.
Conventions
- JSON in camelCase. Request bodies use
maxTokens,topP— notmax_tokens/top_p. - Big amounts are strings. Credit amounts are measured in micro-credits and can exceed JavaScript's safe integer range, so fields like
costMicro,balanceMicro, andbalanceAfterMicroare serialized as strings. Parse them as BigInt or decimal strings, neverparseInt. - Every response carries
X-Request-Id. Send your own (1–128 chars,[A-Za-z0-9._-]) and it is echoed back; otherwise the API generates one. Include it when reporting issues. - Strict request validation. Unknown properties in a request body are rejected with
400— see Errors & rate limits. - Body limits. 1 MB for JSON bodies, 2 MB for agent uploads (
application/octet-stream).
Where to start
- Quickstart — issue a key and make your first request in five minutes.
- Authentication — API keys, scopes, and per-key rate limits.
- Credits & billing — what costs money (only gateway completions) and how billing works.
- API reference — every endpoint, generated from the live OpenAPI spec.