> ## 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. # Stage Computer write bytes > Stages one chunk of content-addressed write bytes under the exact Computer before any operation is admitted. ## OpenAPI ````yaml /openapi.json post /v1/computers/{id}/headless-write-payloads 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; bootstrap poll token; or anonymous bootstrap creation and 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: harnesses - name: harnessRuntime - name: computerProfiles - name: permissionAssignments - name: actionPolicies - name: files - name: memoryStores - name: dreams - name: modelCredentials - name: modelRoutingProfiles - name: blueprintInstallations - name: toolSources - name: skills - name: skillSources - name: agentBlueprints - name: skillProposals - name: instructionProposals - name: catalog - name: concepts - name: support - name: bootstrapRequests - name: connections - name: connectionVaults - name: connectionAssignments - name: connectedRuntimes - name: fileTrees - name: collaboration - name: automationGraphs - name: automations - name: projects - name: actionApprovals - name: standingApprovals - name: workloadReviewPolicies - name: usage - name: models - name: outcomes - name: budgets - name: billing - name: sessions - name: audit - name: sessionExports - name: runs - name: runnerPools - name: transcripts - name: sessionWatches - name: sessionHandoffs - name: sessionCapsules - name: sessionTrajectories - name: webhookEndpoints - name: integrationGateway - name: workEnvironments - name: computers - name: computerScreens - name: computerBrowserObservations - name: computerBrowserActions - name: environments - name: computerHeadlessOperations - name: vaults - name: apiMcp - name: a2a paths: /v1/computers/{id}/headless-write-payloads: post: tags: - computerHeadlessOperations summary: Stage Computer write bytes description: >- Stages one chunk of content-addressed write bytes under the exact Computer before any operation is admitted. The chunk names only the payload digest, byte length, chunk index, and base64 bytes — never a path or operation — so staged bytes stay inert until an admitted write with the same digest and length claims them through an exact execution claim. The payload seals only when every chunk arrives with exact framing and a streaming SHA-256 equal to the digest; a sealed replay extends retention without replacing bytes, an unsealed conflict discards the upload, and a bounded sweep removes expired payloads. Staging confers no execution authority and performs no provider contact. Checkfu support posture: alpha; hosted. No release evidence journey applies to this operation. operationId: computerHeadlessOperations.stageComputerHeadlessWritePayload parameters: - name: id in: path schema: $ref: '#/components/schemas/ComputerId' required: true - name: checkfu-version in: header schema: type: string enum: - '2026-08-31' required: true - name: idempotency-key in: header schema: type: string allOf: - maxLength: 255 required: false requestBody: content: application/json: schema: $ref: '#/components/schemas/ComputerHeadlessWritePayloadChunk' required: true responses: '202': description: >- Acknowledgement for one staged write-payload chunk: whether custody is still staging or sealed against its digest, and whether this exact chunk replayed existing sealed bytes (which extends their retention). content: application/json: schema: $ref: '#/components/schemas/ComputerHeadlessWritePayloadStageReceipt' 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: type: object required: - error properties: error: type: object properties: type: type: string enum: - validation.malformed 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. required: - type - message - more additionalProperties: false additionalProperties: false '401': description: Typed Checkfu wire error content: application/json: schema: type: object required: - error properties: error: type: object required: - type - message - more properties: type: 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. additionalProperties: false 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 required: - error properties: error: type: object properties: type: 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 - message - more additionalProperties: false additionalProperties: false - $ref: '#/components/schemas/PolicyDeniedError' '404': description: >- The requested resource does not exist in the resolved deployment boundary. content: application/json: schema: $ref: '#/components/schemas/ValidationNotFoundError' '409': description: The request conflicts with the resource's current state. content: application/json: schema: $ref: '#/components/schemas/ValidationConflictError' '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 required: - error properties: error: type: object required: - type - message - more properties: type: 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. additionalProperties: false additionalProperties: false '500': description: >- An unexpected internal failure occurred; the message contains an opaque incident reference. content: application/json: schema: $ref: '#/components/schemas/RuntimeInternalError' security: - bearerAuth: [] components: schemas: ComputerId: type: string allOf: - pattern: ^comp_[0-9a-f]{32}$ ComputerHeadlessWritePayloadChunk: type: object properties: content_digest: type: string allOf: - pattern: ^sha256:[0-9a-f]{64}$ byte_length: type: integer allOf: - minimum: 0 maximum: 16777216 chunk_index: type: integer allOf: - minimum: 0 maximum: 5 content_base64: type: string allOf: - maxLength: 4194304 required: - content_digest - byte_length - chunk_index - content_base64 additionalProperties: false ComputerHeadlessWritePayloadStageReceipt: type: object properties: status: type: string enum: - staging - sealed replayed: type: boolean required: - status - replayed additionalProperties: false description: >- Acknowledgement for one staged write-payload chunk: whether custody is still staging or sealed against its digest, and whether this exact chunk replayed existing sealed bytes (which extends their retention). WorkspaceId: type: string allOf: - pattern: ^wrkspc_[0-9a-f]{32}$ PolicyDeniedError: type: object properties: error: type: object properties: type: type: string enum: - policy.denied 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. required: - type - message - more additionalProperties: false required: - error additionalProperties: false description: Deployment governance or retention policy denied the request. ValidationNotFoundError: type: object properties: error: type: object properties: type: type: string enum: - validation.not_found message: type: string more: type: string enum: - https://docs.checkfu.com/reference/errors#validation-not-found description: Stable public documentation and remedy for this error type. required: - type - message - more additionalProperties: false required: - error additionalProperties: false description: >- The requested resource does not exist in the resolved deployment boundary. ValidationConflictError: type: object properties: error: type: object properties: type: type: string enum: - validation.conflict 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. required: - type - message - more additionalProperties: false required: - error additionalProperties: false description: The request conflicts with the resource's current state. RuntimeInternalError: type: object properties: error: type: object properties: type: type: string enum: - runtime.internal 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. required: - type - message - more additionalProperties: false required: - error additionalProperties: false description: >- An unexpected internal failure occurred; the message contains an opaque incident reference. securitySchemes: bearerAuth: type: http scheme: bearer ````