> ## 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>

### Query Parameters

<ParamField query="platform" type="string" required>
  The prediction market platform (e.g., `polymarket`).
</ParamField>

<ParamField query="outcomeId" type="string" required>
  The outcome token ID.
</ParamField>

<ParamField query="period" type="string" default="5m">
  Sampling period. Possible values: `1m`, `5m`, `15m`, `1h`, `4h`, `1d`.
</ParamField>

<ParamField query="limit" type="number" default="100">
  Maximum number of data points to return (1 to 500).
</ParamField>

<ParamField query="offset" type="number" default="0">
  Number of records to skip for pagination.
</ParamField>

### Response

<ResponseField name="data" type="array">
  Array of orderbook depth snapshots.

  <Expandable title="Depth Snapshot">
    <ResponseField name="timestamp" type="number">Timestamp in milliseconds.</ResponseField>
    <ResponseField name="bestBidUSD" type="number">Best bid price at this time.</ResponseField>
    <ResponseField name="bestAskUSD" type="number">Best ask price at this time.</ResponseField>
    <ResponseField name="spreadUSD" type="number">Bid-ask spread.</ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="pagination" type="object">
  Pagination metadata.

  <Expandable title="Pagination Object">
    <ResponseField name="page" type="number">Current page number (1-based).</ResponseField>
    <ResponseField name="offset" type="number">Number of records skipped.</ResponseField>
    <ResponseField name="limit" type="number">Maximum records per page.</ResponseField>
    <ResponseField name="pageEntries" type="number">Number of records returned in this page.</ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="hostname" type="string">Server hostname that handled the request.</ResponseField>
<ResponseField name="took" type="number">Time in milliseconds the request took to process.</ResponseField>

### Usage Example

```bash theme={null}
curl -X GET "https://api.mobula.io/api/2/pm/market/spread-history?platform=polymarket&outcomeId=71321...&period=1h&limit=50"
```

### Example Response

```json theme={null}
{
  "data": [
    { "timestamp": 1709910000000, "bestBidUSD": 0.34, "bestAskUSD": 0.36, "spreadUSD": 0.02 },
    { "timestamp": 1709913600000, "bestBidUSD": 0.35, "bestAskUSD": 0.37, "spreadUSD": 0.02 }
  ],
  "pagination": { "page": 1, "offset": 0, "limit": 100, "pageEntries": 2 },
  "hostname": "pm-api-prod-eu-abc12",
  "took": 42
}
```


## 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

````