openapi: 3.0.3
info:
  title: Navan Bookings Custom Fields API
  description: 'The Navan API is the public developer surface for the Navan (formerly TripActions) corporate travel, expense, and corporate card platform. It is a REST/HTTPS API secured with OAuth 2.0 using the client-credentials grant. Administrators generate a client_id / client_secret in the Navan app under Settings > Integrations (API), exchange them for a Bearer access token, and call the API with `Authorization: Bearer <token>`. Access is scoped (e.g. bookings:read, users:read, users:write, users:delete, and the expense read/write scopes).


    Endpoint status: the Expense API paths (transactions, fees, adjustments, receipts, custom fields) and the travel/v1 Users paths are CONFIRMED against Navan''s published API reference and third-party integration guides. The Bookings and Webhook subscription-management paths are MODELED - the relevant scopes and capabilities are documented by Navan, but the exact request paths are behind a gated reference and are represented here as a best-effort model. Modeled operations are flagged with `x-endpoint-status: modeled`.'
  version: '1.0'
  contact:
    name: Navan Developers
    url: https://developer.navan.com/
  x-rebrand-note: Navan was known as TripActions until its February 2022 rebrand to Navan; some legacy hostnames and token paths still carry a `ta-` (TripActions) prefix, e.g. the `ta-auth` OAuth token path.
servers:
- url: https://api.navan.com
  description: Navan API (US / global)
security:
- oauth2ClientCredentials: []
tags:
- name: Custom Fields
  description: Company custom fields used for cost-center / GL coding. CONFIRMED.
paths:
  /v1/expense/custom-fields:
    get:
      operationId: listCustomFields
      tags:
      - Custom Fields
      summary: List custom fields
      description: List all company custom fields. CONFIRMED.
      responses:
        '200':
          description: A list of custom fields.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/CustomField'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v1/expense/custom-fields/{fieldName}:
    parameters:
    - $ref: '#/components/parameters/FieldName'
    get:
      operationId: getCustomField
      tags:
      - Custom Fields
      summary: Get a custom field
      description: Retrieve a single custom field definition by name. CONFIRMED.
      responses:
        '200':
          description: The requested custom field.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CustomField'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /v1/expense/custom-fields/{fieldName}/options:
    parameters:
    - $ref: '#/components/parameters/FieldName'
    post:
      operationId: manageCustomFieldOptions
      tags:
      - Custom Fields
      summary: Batch manage custom field options
      description: Batch-create or update the options (values) available on a custom field. CONFIRMED.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CustomFieldOptionsInput'
      responses:
        '200':
          description: Job accepted (may run asynchronously).
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Job'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /v1/expense/custom-fields/jobs/{job_id}:
    parameters:
    - name: job_id
      in: path
      required: true
      description: The asynchronous job ID returned by an options-management request.
      schema:
        type: string
    get:
      operationId: getCustomFieldJob
      tags:
      - Custom Fields
      summary: Get custom field job status
      description: Poll the status of an asynchronous custom-field options job. CONFIRMED.
      responses:
        '200':
          description: Job status.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Job'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorized:
      description: Missing or invalid access token, or insufficient scope.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    CustomFieldOptionsInput:
      type: object
      required:
      - options
      properties:
        options:
          type: array
          items:
            type: object
            properties:
              value:
                type: string
              action:
                type: string
                enum:
                - add
                - update
                - remove
    Job:
      type: object
      properties:
        job_id:
          type: string
        status:
          type: string
          enum:
          - pending
          - running
          - completed
          - failed
    CustomField:
      type: object
      properties:
        name:
          type: string
        label:
          type: string
        type:
          type: string
        required:
          type: boolean
        options:
          type: array
          items:
            type: string
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: string
            message:
              type: string
            details:
              type: object
              additionalProperties: true
  parameters:
    FieldName:
      name: fieldName
      in: path
      required: true
      description: The custom field name.
      schema:
        type: string
  securitySchemes:
    oauth2ClientCredentials:
      type: oauth2
      description: 'OAuth 2.0 client-credentials flow. Generate a client_id / client_secret in the Navan app under Settings > Integrations (API), then POST grant_type=client_credentials to the token URL to obtain a Bearer access token. US token URL: https://app.navan.com/ta-auth/oauth/token ; EU token URL: https://app-fra.navan.com/ta-auth/oauth/token . (Some integrations reference an https://api.navan.com/ta-auth/oauth/token or /auth/v1/token variant; confirm the current token URL in the Navan developer portal.)'
      flows:
        clientCredentials:
          tokenUrl: https://app.navan.com/ta-auth/oauth/token
          scopes:
            bookings:read: Read booking (trip) data.
            users:read: Read user profiles.
            users:write: Create and modify users.
            users:delete: Deactivate users.
            liquid:read: Read expense data (transactions, fees, receipts, custom fields).
            liquid:write: Update expense data.