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

# Apr-Basis Constant Maturity

> This endpoint returns the quoted futures basis for various exchanges, interpolated to reflect a constant days to expiration (DTE).



## OpenAPI

````yaml get /analytics/futures-perpetuals/apr-basis/constant-maturities
openapi: 3.1.0
info:
  title: derivatives-api
  version: '2'
servers:
  - url: https://api.amberdata.com/markets/derivatives
security:
  - sec0: []
paths:
  /analytics/futures-perpetuals/apr-basis/constant-maturities:
    get:
      summary: Apr-Basis Constant Maturity
      description: >-
        This endpoint returns the quoted futures basis for various exchanges,
        interpolated to reflect a constant days to expiration (DTE).
      operationId: derivatives-futures-perpetuals-apr-basis-constant-maturities
      parameters:
        - name: asset
          in: query
          description: >-
            **[Required]** The underlying currency for which there are futures
            contracts/instruments. 

            **[Examples]** ` BTC | ETH `
          required: true
          schema:
            type: string
            default: BTC
        - name: interval
          in: query
          description: >-
            **[Required]** This interval parameter filters for the selected
            constant maturity DTE (Days To Expiration). 

            **[Examples]** ` 7D | 30D | 90D |180D`
          required: true
          schema:
            type: string
            default: 30D
        - name: startDate
          in: query
          description: >-
            **[Required]** Payload only includes data after this date
            (inclusive). 

            **[Formats]** `seconds | milliseconds | iso8601`

            **[Examples]** `1578531600 | 1578531600000 | 2020-09-01T01:00:00`
          required: true
          schema:
            type: string
            format: date-time
            default: '2024-05-21'
        - name: endDate
          in: query
          description: >-
            **[Required]** Payload only includes data before this date
            (exclusive). 

            **[Formats]** `seconds | milliseconds | iso8601`

            **[Examples]** `1578531600 | 1578531600000 | 2020-09-01T01:00:00`
          required: true
          schema:
            type: string
            default: '2024-06-01'
        - name: timeFormat
          in: query
          description: >-
            **[Optional]** Time format of the timestamps in the return payload.

            **[Defaults]** `milliseconds | ms* | iso | iso8601 | hr |
            human_readable`
          schema:
            type: string
      responses:
        '200':
          description: '200'
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: integer
                    example: 200
                  title:
                    type: string
                    example: OK
                  description:
                    type: string
                    example: Successful request
                  payload:
                    type: object
                    properties:
                      data:
                        type: array
                        items:
                          type: object
                          properties:
                            timestamp:
                              type: string
                              example: '1704067200000'
                              description: Timestamp for the basis and APR data point
                            symbol:
                              type: string
                              example: bybit_BTC-USDC
                              description: The exchange and trading pair symbol
                            basisUSD:
                              type: number
                              example: 293.8
                              description: The futures basis in USD terms
                            apr:
                              type: number
                              example: 36.11
                              description: >-
                                The annualized percentage rate (APR) for the
                                basis
              examples:
                Result:
                  value:
                    status: 200
                    title: OK
                    description: Successful request
                    payload:
                      data:
                        - timestamp: '1704067200000'
                          symbol: bybit_BTC-USDC
                          basisUSD: 293.8
                          apr: 36.11
                        - timestamp: '1704067200000'
                          symbol: deribit_BTC-USD
                          basisUSD: 296
                          apr: 36.38
                        - timestamp: '1704067200000'
                          symbol: huobi_BTC-USD
                          basisUSD: 283.9
                          apr: 34.89
                        - timestamp: '1704067200000'
                          symbol: okex_BTC-USD
                          basisUSD: 297.3
                          apr: 36.54
                        - timestamp: '1704067200000'
                          symbol: okex_BTC-USDC
                          basisUSD: 287
                          apr: 35.28
                        - timestamp: '1704067200000'
                          symbol: okex_BTC-USDT
                          basisUSD: 290.3
                          apr: 35.68
                        - timestamp: '1704070800000'
                          symbol: bybit_BTC-USDC
                          basisUSD: 300.9
                          apr: 36.86
                        - timestamp: '1704070800000'
                          symbol: deribit_BTC-USD
                          basisUSD: 301.6
                          apr: 36.96
                        - timestamp: '1704070800000'
                          symbol: huobi_BTC-USD
                          basisUSD: 280.7
                          apr: 34.4
                        - timestamp: '1704070800000'
                          symbol: okex_BTC-USD
                          basisUSD: 302.9
                          apr: 37.12
                        - timestamp: '1704070800000'
                          symbol: okex_BTC-USDC
                          basisUSD: 292.8
                          apr: 35.88
                        - timestamp: '1704070800000'
                          symbol: okex_BTC-USDT
                          basisUSD: 298.3
                          apr: 36.55
                        - timestamp: '1704074400000'
                          symbol: bybit_BTC-USDC
                          basisUSD: 306.6
                          apr: 37.57
                        - timestamp: '1704074400000'
                          symbol: deribit_BTC-USD
                          basisUSD: 305.6
                          apr: 37.44
                        - timestamp: '1704074400000'
                          symbol: huobi_BTC-USD
                          basisUSD: 277.3
                          apr: 33.98
                        - timestamp: '1704074400000'
                          symbol: okex_BTC-USD
                          basisUSD: 311
                          apr: 38.1
                        - timestamp: '1704074400000'
                          symbol: okex_BTC-USDC
                          basisUSD: 301.3
                          apr: 36.92
                        - timestamp: '1704074400000'
                          symbol: okex_BTC-USDT
                          basisUSD: 298.3
                          apr: 36.55
        '400':
          description: '400'
          content:
            application/json:
              examples:
                Result:
                  value: {}
              schema:
                type: object
                properties: {}
      deprecated: false
      security:
        - ApiKeyAuth: []
components:
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key

````