> ## Documentation Index > Fetch the complete documentation index at: https://docs.fabro.sh/llms.txt > Use this file to discover all available pages before exploring further. # Create Workflow Version > Validates and stores an immutable workflow package in content-addressed storage. Repeating the same canonical content returns the same identifier. ## OpenAPI ````yaml /api-reference/fabro-api.yaml post /api/v1/workflow-versions openapi: 3.1.0 info: title: Fabro Run API version: 0.2.0 description: HTTP API for managing Fabro workflow run executions. servers: [] security: - BearerAuth: [] - SessionCookie: [] tags: - name: Discovery description: API discovery and health - name: Install description: First-run browser install workflow - name: Integrations description: External provider callbacks and integration endpoints - name: Auth description: Browser authentication - name: Runs description: Run management operations - name: Automations description: Server-managed automation definitions and automation-triggered runs - name: Environments description: Server-managed execution environment catalog - name: MCP Servers description: >- Server-managed MCP server definitions referenced by id from workflow configs - name: Sandboxes description: Provider-backed sandbox inventory - name: Sessions description: Ask Fabro sessions bound to runs - name: Human-in-the-Loop description: Questions, answers, and steering for runs - name: Run Outputs description: Files produced by runs - name: Run Internals description: Internal run details (stages, turns, context, configuration) - name: Workflows description: Workflow definitions and execution - name: Workflow Versions description: Immutable, content-addressed workflow packages - name: Billing description: Token counts and billed totals - name: Insights description: SQL query editor and history - name: Models description: Available LLM models - name: Completions description: Single-turn LLM completions - name: Settings description: Platform configuration - name: System description: Server runtime, maintenance, and event streaming paths: /api/v1/workflow-versions: post: tags: - Workflow Versions summary: Create Workflow Version description: >- Validates and stores an immutable workflow package in content-addressed storage. Repeating the same canonical content returns the same identifier. operationId: createWorkflowVersion requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/WorkflowVersion' responses: '201': description: Workflow version stored or already present content: application/json: schema: $ref: '#/components/schemas/CreateWorkflowVersionResponse' '400': description: Malformed JSON (`invalid_json`) headers: x-request-id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '413': description: Request body exceeds 2 MiB (`workflow_version_too_large`) headers: x-request-id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: >- Invalid workflow content (`workflow_version_invalid`) or an absent, invalid, or non-canonical dependency (`workflow_version_dependency_not_found`) headers: x-request-id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Workflow version storage failed headers: x-request-id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' components: schemas: WorkflowVersion: description: >- Complete immutable package for one rooted workflow. It contains at most 512 files and 512 workflow dependencies, each file is at most 512 KiB of UTF-8 content, and its compact canonical JSON representation is at most 2 MiB. type: object additionalProperties: false required: - entrypoint - files - workflow_dependencies properties: entrypoint: $ref: '#/components/schemas/WorkflowPath' files: type: object description: >- Workflow-local text files keyed by canonical path. Keys receive stricter domain validation than OpenAPI can express; each value is limited to 512 KiB of UTF-8 bytes. maxProperties: 512 propertyNames: $ref: '#/components/schemas/WorkflowPath' additionalProperties: type: string workflow_dependencies: type: object description: >- Exact stored workflow-version IDs keyed by resolved child-workflow path. Keys receive stricter domain validation than OpenAPI can express. maxProperties: 512 propertyNames: $ref: '#/components/schemas/WorkflowPath' additionalProperties: $ref: '#/components/schemas/WorkflowVersionId' CreateWorkflowVersionResponse: description: Identity of the stored immutable workflow version. type: object additionalProperties: false required: - workflow_version_id properties: workflow_version_id: $ref: '#/components/schemas/WorkflowVersionId' ErrorResponse: description: Standard error response containing one or more error entries. type: object required: - errors properties: errors: type: array description: List of error entries. items: $ref: '#/components/schemas/ErrorResponseEntry' request_id: type: string format: uuid description: >- Server-generated request identifier; matches the x-request-id response header. leftover_env_keys: type: array description: >- Optional list of runtime env keys that were written before an install failure. Currently populated by `POST /install/finish` failure responses only. items: type: string removed_env_keys: type: array description: >- Optional list of runtime env keys that were actually removed before an install failure. Currently populated by `POST /install/finish` failure responses only. items: type: string WorkflowPath: description: >- Canonical portable path inside one workflow version. Paths are UTF-8, relative, at most 240 bytes and 16 components, and cannot contain empty, dot, parent, backslash, control, tilde-root, or drive-letter segments. Map keys receive stricter byte and structural validation in the domain model than OpenAPI can express. type: string minLength: 1 maxLength: 240 example: graphs/main.fabro WorkflowVersionId: description: >- SHA-256 identity of validated canonical workflow-version bytes. Hex input is case-insensitive; Fabro emits the canonical lowercase form. type: string pattern: ^[0-9A-Fa-f]{64}$ example: 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef ErrorResponseEntry: description: A single error entry in an error response. type: object required: - status - title - detail properties: status: type: string description: HTTP status code as a string. example: '404' title: type: string description: Short error classification. example: Not Found detail: type: string description: Human-readable error description. example: Run not found. code: type: string description: Optional machine-readable error code for structured client handling. example: access_token_expired request_id: type: string format: uuid description: >- Server-generated request identifier; matches the x-request-id response header. headers: XRequestId: description: > Server-generated request identifier emitted on every response and referenced on standard error responses for correlating client errors with server logs. schema: type: string format: uuid securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: opaque description: > Raw dev token passed as `Authorization: Bearer fabro_dev_...` when `server.auth.methods` includes `dev-token`. SessionCookie: type: apiKey in: cookie name: __fabro_session description: > Private session cookie issued after a successful web login. The server verifies and decodes the cookie before authenticating the request. ````