ThetaData Interest Rate API

openapi: 3.1.0
info:
  title: Theta Data v3 At-Time Interest Rate API
  description: Real-time and historic stock, options, and index data!
  version: 3.0.0
  x-java-package: net.thetadata.generated
servers:
- url: http://127.0.0.1:25503/v3
  description: dev
security: []
tags:
- name: Interest Rate
paths:
  /interest_rate/history/eod:
    x-concurrent-limit-ttl-ms: '15'
    x-min-subscription: free
    get:
      summary: End of Day
      operationId: interest_rate_history_eod
      x-codeSamples:
      - lang: Python
        label: pandas
        source: "from thetadata import ThetaClient\nfrom datetime import date\n\nclient = ThetaClient(dataframe_type='pandas')\ndf = client.interest_rate_history_eod(\n    symbol='SOFR',\n    start_date=date(2025, 11, 4),\n    end_date=date(2025, 11, 8),\n)\n"
      - lang: Python
        label: polars
        source: "from thetadata import ThetaClient\nfrom datetime import date\n\nclient = ThetaClient(dataframe_type='polars')\ndf = client.interest_rate_history_eod(\n    symbol='SOFR',\n    start_date=date(2025, 11, 4),\n    end_date=date(2025, 11, 8),\n)\n"
      tags:
      - Interest Rate
      description: '- Returns the interest rate reported. Depending on the rate, reports can occur in the morning or the afternoon.

        '
      x-sample-urls:
      - url: http://127.0.0.1:25503/v3/interest_rate/history/eod?symbol=SOFR&start_date=20251104&end_date=20251108
        description: Returns the rate for a given symbol between specified dates (inclusive)
      parameters:
      - $ref: '#/components/parameters/single_symbol'
      - $ref: '#/components/parameters/start_date'
      - $ref: '#/components/parameters/end_date'
      - $ref: '#/components/parameters/format'
      responses:
        '200':
          description: Returns the interest rate for a given symbol between specified dates (inclusive)
          content:
            text/csv:
              schema:
                type: array
                items: &id001
                  type: object
                  properties:
                    created:
                      type: string
                      format: date
                      description: The date formated as YYYY-MM-DD format.
                    rate:
                      type: number
                      description: The interest rate express as a percent (i.e 1.25% is 1.25).
              example: "created,rate\r\n 2025-11-04,4.0000\r\n 2025-11-05,3.9100\r\n 2025-11-06,3.9200\r\n 2025-11-07,3.9300\r\n 20251108,3.9400\r\n"
            application/json:
              schema: &id002
                type: array
                items: *id001
              example: "{\n  \"response\": [\n    {\"rate\":4.0000,\"created\":\"2025-11-04\"}\n    {\"rate\":3.9100,\"created\":\"2025-11-05\"}\n    {\"rate\":3.9200,\"created\":\"2025-11-06\"}\n    {\"rate\":3.9300,\"created\":\"2025-11-07\"}\n    {\"rate\":3.9400,\"created\":\"2025-11-08\"}\n  ]\n}\n"
            application/x-ndjson:
              schema: *id002
              example: '{"rate":4.0000,"created":"2025-11-04"}

                {"rate":3.9100,"created":"2025-11-05"}

                {"rate":3.9200,"created":"2025-11-06"}

                {"rate":3.9300,"created":"2025-11-07"}

                {"rate":3.9400,"created":"2025-11-08"}'
            python/pandas:
              schema: *id002
              example: 'created  rate

                0  2026-11-04  3.66

                1  2026-11-05  3.66

                2  2026-11-06  3.66

                3  2026-11-07  3.66

                4  2026-11-08  3.66

                5  2026-11-09  3.66

                '
            python/polars:
              schema: *id002
              example: 'shape: (6, 2)

                ┌────────────┬──────┐

                │ created    ┆ rate │

                │ ---        ┆ ---  │

                │ str        ┆ f64  │

                ╞════════════╪══════╡

                │ 2026-11-04 ┆ 3.66 │

                │ 2026-11-05 ┆ 3.66 │

                │ 2026-11-06 ┆ 3.66 │

                │ 2026-11-07 ┆ 3.66 │

                │ 2026-11-08 ┆ 3.66 │

                │ 2026-11-09 ┆ 3.66 │

                └────────────┴──────┘

                '
components:
  parameters:
    start_date:
      name: start_date
      in: query
      description: The start date (inclusive).
      required: true
      schema:
        type: string
        format: date
    end_date:
      name: end_date
      in: query
      description: The end date (inclusive).
      required: true
      schema:
        type: string
        format: date
    format:
      name: format
      in: query
      description: The format of the data when returned to the user.
      required: false
      schema:
        type: string
        enum:
        - csv
        - json
        - ndjson
        - html
        default: csv
    single_symbol:
      name: symbol
      in: query
      description: The stock or index symbol, or underlying symbol for options.
      required: true
      schema:
        type: string