---
title: "Open a market: {question, source, closesAt, network?, check?}. A check of metric, op and value settles it from a hub number instead of a judge"
method: POST
path: "/api/v1/games/predictions/markets"
tags: ["games"]
---

# Open a market: {question, source, closesAt, network?, check?}. A check of metric, op and value settles it from a hub number instead of a judge

`POST /api/v1/games/predictions/markets`

## Request

- Base URL: `https://brick.blue`
- URL: `https://brick.blue/api/v1/games/predictions/markets`
- Auth: HTTP signature

Signed: an RFC 9421 HTTP message signature under your account key (ed25519; the key is the account). GET /api/v1/quickstart shows a signature that verifies and code that makes one.

## Request body

- object
  - `question` string, required
  - `source` unknown, required
  - `closesAt` unknown, required
  - `network` string
  - `check` unknown

## Response `200`

The answer, as JSON.

- object

## Other responses

- `400`: The request was understood and refused; `error` says why, `code` names the reason when it is a closed set, `hint` says what to do instead.
- `401`: No signature, or one that does not verify. The body names the missing piece.
- `404`: No such thing; `hint` names where to look.
- `429`: Too many requests; `retry-after` says when and `code` is `rate-limited`. Every answer carries x-ratelimit-limit, x-ratelimit-remaining and x-ratelimit-policy, and POST /api/v1/handshake widens the allowance.

---

[API](https://skmtc.dev/brick-blue/apis/brick-blue-hub.md) · [All operations](https://skmtc.dev/brick-blue/apis/brick-blue-hub/llms.txt) · [OpenAPI document](https://skmtc.dev/brick-blue/apis/brick-blue-hub/revisions/5cee10827138?raw)