> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mobula.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Get Prediction Spread History

> Get historical bid/ask spread evolution for a specific outcome. This is a time-series of spread data, not a live order book (see Market Order Book for live bids/asks).

<Warning>**Alpha** — This endpoint is part of the Prediction Markets API, currently in early access. May change without notice.</Warning>


## OpenAPI

````yaml GET /2/pm/market/spread-history
openapi: 3.0.0
info:
  version: 1.0.0
  title: Mobula Prediction Markets API
  description: >-
    Documentation of the Mobula Prediction Markets API.


    The PM API is currently served from a dedicated host:
    `pm-api-prod-eu.mobula.io`.

    All endpoints below require an API key (same key as the main Mobula API).


    Parameter names below are the **canonical names enforced by the API

    controllers** (Zod-validated). Following the wrong name (e.g. `?market=...`

    instead of `?platform=...&marketId=...`) returns `HTTP 400`.
servers:
  - url: https://pm-api-prod-eu.mobula.io/api/
    description: PM Production API (requires API key)
security: []
tags:
  - name: V2 - PM Market
    description: Prediction market data — details, prices, order book, trades, OHLCV
  - name: V2 - PM Discovery
    description: Search, trending, categories, live markets
  - name: V2 - PM Wallet
    description: Wallet prediction-market positions, balances, PnL, activity, status
paths:
  /2/pm/market/spread-history:
    get:
      tags:
        - V2 - PM Market
      summary: Get Prediction Spread History
      description: |
        Get historical bid/ask spread evolution for a specific outcome.

        Time-series of `(bestBidUSD, bestAskUSD, spreadUSD)` per candle —
        **not** a live order book (use `/2/pm/market/book` for that).
      parameters:
        - $ref: '#/components/parameters/Platform'
        - $ref: '#/components/parameters/OutcomeId'
        - name: period
          in: query
          required: false
          description: Candle resolution.
          schema:
            type: string
            enum:
              - 1m
              - 5m
              - 15m
              - 1h
              - 4h
              - 1d
            default: 5m
        - name: limit
          in: query
          required: false
          description: Page size (1-500).
          schema:
            type: integer
            minimum: 1
            maximum: 500
            default: 100
        - $ref: '#/components/parameters/Offset'
      responses:
        '200':
          description: Spread history
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      type: object
components:
  parameters:
    Platform:
      name: platform
      in: query
      required: true
      description: >-
        Prediction market platform. Today only `polymarket` is supported; any
        other value returns 400.
      schema:
        type: string
        enum:
          - polymarket
        example: polymarket
    OutcomeId:
      name: outcomeId
      in: query
      required: true
      description: >-
        Polymarket outcome / token ID — uint256 decimal string (the ERC-1155
        token id of the YES/NO/etc. side).
      schema:
        type: string
        pattern: ^[0-9]+$
        example: >-
          59855952379545476461266875939089074481171378466995213858930892770855011813551
    Offset:
      name: offset
      in: query
      required: false
      description: Pagination offset.
      schema:
        type: integer
        minimum: 0
        default: 0

````