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

> ## Agent Instructions
> Base URL: https://api.checkfu.com. Current wire version: `2026-08-31` (`Checkfu-Version: 2026-08-31`).
> Mutating HTTP requests require `Authorization: Bearer $CHECKFU_API_KEY`, `Checkfu-Version: 2026-08-31`, `Content-Type: application/json`, and `Idempotency-Key` on retriable writes. Ordinary API keys are Workspace-bound; do not send a Workspace selector header.
> Core workflow: create an Agent (`POST /v1/agents`) and Environment (`POST /v1/environments`), grant `use_environment` (`POST /v1/permission-assignments`), create a Session (`POST /v1/sessions`), send events (`POST /v1/sessions/{id}/events`), stream progress (`GET /v1/sessions/{id}/events/stream`), and read the input result (`GET /v1/sessions/{id}/inputs/{input_id}/result`).
> Domain model: an Agent is mutable configuration; a Session freezes its AgentVersion and Environment at creation and owns its private workspace and ordered event history. Vault stores secret credentials; Connection links an external account; ActionApproval records human approval before an action runs.
> Capability status combines `audience`, `stability`, `availability`, evaluated prerequisites, and release evidence; check https://docs.checkfu.com/getting-started/status (`GET /v1/support/capabilities`) for live `available` status.

# Refund the unused prepaid balance

> Asks for the unused prepaid balance back on account closure, rounded down to whole US cents.



## OpenAPI

````yaml /openapi.json post /v1/billing/credits/refunds
openapi: 3.1.0
info:
  title: Checkfu API
  version: '2026-08-31'
  description: >-
    Authentication is declared per operation: API-key, runtime, or connector
    bearer; Automation signature; or credential-free pairing redemption. Every
    general Checkfu REST request requires the dated `Checkfu-Version` header
    (one of: 2026-08-31); the three MCP JSON-RPC transports use
    `MCP-Protocol-Version`, A2A uses `A2A-Version`, and the provider OAuth
    callback carries neither Checkfu header. API keys resolve one Workspace
    without a request selector; authenticated responses identify it with
    `Checkfu-Workspace-Id`.
servers:
  - url: https://api.checkfu.com
security:
  - bearerAuth: []
tags:
  - name: organizations
  - name: sourceRepositories
  - name: tenants
  - name: workspaces
  - name: principals
  - name: principalGroups
  - name: principalAccessCredentials
  - name: apiKeys
  - name: agents
  - name: harnessRuntime
  - name: permissionAssignments
  - name: actionPolicies
  - name: organizationActionPolicies
  - name: files
  - name: memoryStores
  - name: modelCredentials
  - name: modelRoutingProfiles
  - name: toolSources
  - name: skills
  - name: skillSources
  - name: skillProposals
  - name: instructionProposals
  - name: catalog
  - name: concepts
  - name: support
  - name: connections
  - name: connectionAssignments
  - name: connectedRuntimes
  - name: fileTrees
  - name: collaboration
  - name: automations
  - name: actionApprovals
  - name: standingApprovals
  - name: workloadReviewPolicies
  - name: usage
  - name: models
  - name: budgets
  - name: billing
  - name: sessions
  - name: audit
  - name: sessionExports
  - name: runs
  - name: runnerPools
  - name: transcripts
  - name: sessionWatches
  - name: sessionCapsules
  - name: sessionTrajectories
  - name: webhookEndpoints
  - name: integrationGateway
  - name: environments
  - name: vaults
  - name: apiMcp
  - name: a2a
paths:
  /v1/billing/credits/refunds:
    post:
      tags:
        - billing
      summary: Refund the unused prepaid balance
      description: >-
        Asks for the unused prepaid balance back on account closure, rounded
        down to whole US cents. The amount is fenced at once, so no Session or
        Automation can spend it while the payout is pending or its state is
        unknown. The payout runs through Autumn's payment provider; the refund
        reads paid once the purchase history shows it on the purchases it was
        allocated to, and billing status shows it under refunding until then.
        One closure refund is pending at a time; asking again while one is
        pending answers that refund with 200, never a second payout, so a retry
        after a lost reply finds its own refund. Offered only where prepaid
        purchases are enabled; refund terms are not approved for live money.
        Requires Idempotency-Key.


        Checkfu support posture: preview; rollout_fenced. Required evidence
        journey: platform-supply-billing. Deployment-specific readiness and the
        latest proven release are available from GET /v1/support/capabilities.
      operationId: billing.createCreditRefund
      parameters:
        - name: checkfu-version
          in: header
          schema:
            type: string
            enum:
              - '2026-08-31'
          required: true
        - name: idempotency-key
          in: header
          schema:
            type: string
            minLength: 1
            maxLength: 255
          required: true
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                reason:
                  type: string
                  enum:
                    - account_closure
                  description: >-
                    Why the balance is refunded. Only closure is offered: the
                    unused balance is refunded in whole cents and fenced from
                    spending until the payout completes.
              required:
                - reason
              additionalProperties: false
        required: true
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Objects_164'
          headers:
            checkfu-workspace-id:
              description: The Workspace resolved from the authenticated bearer credential.
              required: true
              schema:
                $ref: '#/components/schemas/WorkspaceId'
        '201':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Objects_164'
          headers:
            checkfu-workspace-id:
              description: The Workspace resolved from the authenticated bearer credential.
              required: true
              schema:
                $ref: '#/components/schemas/WorkspaceId'
        '400':
          description: Typed Checkfu wire error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationMalformedError'
        '401':
          description: Typed Checkfu wire error
          content:
            application/json:
              schema:
                type: object
                properties:
                  type:
                    type: string
                    enum:
                      - error
                  error:
                    type: object
                    properties:
                      type:
                        type: string
                        enum:
                          - authentication_error
                      code:
                        type: string
                        enum:
                          - auth.invalid_key
                      message:
                        type: string
                      more:
                        type: string
                        enum:
                          - >-
                            https://docs.checkfu.com/reference/errors#auth-invalid-key
                        description: >-
                          Stable public documentation and remedy for this error
                          type.
                    required:
                      - type
                      - code
                      - message
                      - more
                    additionalProperties: false
                  request_id:
                    type: string
                    minLength: 1
                required:
                  - type
                  - error
                  - request_id
                additionalProperties: false
        '403':
          description: >-
            The organization, tenant, or workspace backing this key is
            administratively disabled. | Deployment governance or retention
            policy denied the request.
          content:
            application/json:
              schema:
                anyOf:
                  - type: object
                    properties:
                      type:
                        type: string
                        enum:
                          - error
                      error:
                        type: object
                        properties:
                          type:
                            type: string
                            enum:
                              - permission_error
                          code:
                            type: string
                            enum:
                              - auth.disabled_tenancy
                          message:
                            type: string
                          more:
                            type: string
                            enum:
                              - >-
                                https://docs.checkfu.com/reference/errors#auth-disabled-tenancy
                            description: >-
                              Stable public documentation and remedy for this
                              error type.
                        required:
                          - type
                          - code
                          - message
                          - more
                        additionalProperties: false
                      request_id:
                        type: string
                        minLength: 1
                    required:
                      - type
                      - error
                      - request_id
                    additionalProperties: false
                  - $ref: '#/components/schemas/PolicyDeniedError'
        '409':
          description: >-
            The request conflicts with the resource's current state. | An
            idempotent mutation conflicts with a completed or in-progress
            request for the same key.
          content:
            application/json:
              schema:
                anyOf:
                  - $ref: '#/components/schemas/ValidationConflictError'
                  - $ref: '#/components/schemas/IdempotencyConflictError'
        '429':
          description: Typed Checkfu wire error
          headers:
            retry-after:
              description: >-
                Delay in seconds for rate limits or deployment quotas with a
                known release or UTC reset boundary
              required: false
              schema:
                type: integer
                minimum: 1
          content:
            application/json:
              schema:
                type: object
                properties:
                  type:
                    type: string
                    enum:
                      - error
                  error:
                    type: object
                    properties:
                      type:
                        type: string
                        enum:
                          - rate_limit_error
                      code:
                        type: string
                        enum:
                          - budget.exceeded
                      message:
                        type: string
                      more:
                        type: string
                        enum:
                          - >-
                            https://docs.checkfu.com/reference/errors#budget-exceeded
                        description: >-
                          Stable public documentation and remedy for this error
                          type.
                    required:
                      - type
                      - code
                      - message
                      - more
                    additionalProperties: false
                  request_id:
                    type: string
                    minLength: 1
                required:
                  - type
                  - error
                  - request_id
                additionalProperties: false
        '500':
          description: >-
            An unexpected internal failure occurred; the message contains an
            opaque incident reference.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/RuntimeInternalError'
        '503':
          description: >-
            Commercial entitlement cannot currently authorize Checkfu-funded
            work.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BillingEntitlementUnavailableError'
      security:
        - bearerAuth: []
components:
  schemas:
    Objects_164:
      type: object
      properties:
        refund_id:
          type: string
        reason:
          type: string
          enum:
            - account_closure
        amount_minor_units:
          type: integer
          minimum: -9007199254740991
          maximum: 9007199254740991
        currency:
          type: string
          enum:
            - usd
        state:
          type: string
          enum:
            - pending
            - paid
            - failed
        created_at:
          type: string
      required:
        - refund_id
        - reason
        - amount_minor_units
        - currency
        - state
        - created_at
      additionalProperties: false
    WorkspaceId:
      type: string
      pattern: ^wrkspc_[0-9a-f]{32}$
    ValidationMalformedError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - invalid_request_error
            message:
              type: string
            more:
              type: string
              enum:
                - https://docs.checkfu.com/reference/errors#validation-malformed
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - validation.malformed
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: >-
        The request could not be decoded or violated a declared input
        constraint.
    PolicyDeniedError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - permission_error
            message:
              type: string
            more:
              type: string
              enum:
                - https://docs.checkfu.com/reference/errors#policy-denied
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - policy.denied
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: Deployment governance or retention policy denied the request.
    ValidationConflictError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - conflict_error
            message:
              type: string
            more:
              type: string
              enum:
                - https://docs.checkfu.com/reference/errors#validation-conflict
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - validation.conflict
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: The request conflicts with the resource's current state.
    IdempotencyConflictError:
      anyOf:
        - $ref: '#/components/schemas/ValidationIdempotencyConflictError'
        - $ref: '#/components/schemas/ValidationIdempotencyInProgressError'
      description: >-
        An idempotent mutation conflicts with a completed or in-progress request
        for the same key.
    RuntimeInternalError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - api_error
            message:
              type: string
            more:
              type: string
              enum:
                - https://docs.checkfu.com/reference/errors#runtime-internal
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - runtime.internal
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: >-
        An unexpected internal failure occurred; the message contains an opaque
        incident reference.
    BillingEntitlementUnavailableError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - api_error
            message:
              type: string
            more:
              type: string
              enum:
                - >-
                  https://docs.checkfu.com/reference/errors#billing-entitlement-unavailable
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - billing.entitlement_unavailable
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: Commercial entitlement cannot currently authorize Checkfu-funded work.
    ValidationIdempotencyConflictError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - conflict_error
            message:
              type: string
            more:
              type: string
              enum:
                - >-
                  https://docs.checkfu.com/reference/errors#validation-idempotency-conflict
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - validation.idempotency_conflict
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: The Idempotency-Key is already bound to a different request.
    ValidationIdempotencyInProgressError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
              enum:
                - conflict_error
            message:
              type: string
            more:
              type: string
              enum:
                - >-
                  https://docs.checkfu.com/reference/errors#validation-idempotency-in-progress
              description: Stable public documentation and remedy for this error type.
            code:
              type: string
              enum:
                - validation.idempotency_in_progress
          required:
            - type
            - message
            - more
            - code
          additionalProperties: false
        type:
          type: string
          enum:
            - error
        request_id:
          type: string
          minLength: 1
      required:
        - error
        - type
        - request_id
      additionalProperties: false
      description: >-
        An identical idempotent request is still in progress and may be retried
        later.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer

````

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