> ## Documentation Index > Fetch the complete documentation index at: https://docs.continuouslabs.ai/llms.txt > Use this file to discover all available pages before exploring further. # Create Simulation Snapshot > Saves a running Simulation's current state, or its state after an earlier recorded step when you set at_step, and returns the Snapshot once the state is stored. Saving does not change the Simulation. Create Simulations from the Snapshot with snapshot_id; it outlives its Simulation. A stopped Simulation returns 409 simulation_stopped. Reuse the Idempotency-Key to retry safely. ## OpenAPI ````yaml /openapi/simulation.yaml post /v1/simulation-snapshots openapi: 3.1.0 info: description: >- Build Simulators from OpenAPI, WSDL or GraphQL documents, create Simulations from them, and build Worlds that run Simulations together. Authenticate every request with an API key sent as a Bearer token. title: Continuous Simulation API version: v1 servers: - description: Continuous production API. url: https://api.continuouslabs.ai security: [] tags: - description: >- Build Simulators from OpenAPI, WSDL or GraphQL documents, check or cancel a build, clone Simulators into other workspaces, and rename and delete Simulators. name: simulators x-group: Simulators - description: >- Create Simulations from ready Simulators or Snapshots, then rename, stop, start, and delete them. name: simulations x-group: Simulations - description: >- Save a running Simulation's state as a Snapshot, create Simulations from it, and rename and delete it. name: simulation-snapshots x-group: Simulation Snapshots - description: >- Build Worlds from one or more Simulators, rename them, and start or stop their Simulations together. name: worlds x-group: Worlds - description: >- Store connections to real systems: a base URL, the header that carries the credential, and its value. The API never returns a value. name: credentials x-group: Credentials paths: /v1/simulation-snapshots: post: tags: - simulation-snapshots summary: Create Simulation Snapshot description: >- Saves a running Simulation's current state, or its state after an earlier recorded step when you set at_step, and returns the Snapshot once the state is stored. Saving does not change the Simulation. Create Simulations from the Snapshot with snapshot_id; it outlives its Simulation. A stopped Simulation returns 409 simulation_stopped. Reuse the Idempotency-Key to retry safely. operationId: create-simulation-snapshot parameters: - description: >- Optional key for retrying this create safely. A retry with the same key and request returns the original result with its status; the same key with a different request returns 409 idempotency_conflict. Without a key, each request creates a new resource. in: header name: Idempotency-Key schema: maxLength: 256 type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateSimulationSnapshotRequest' required: true responses: '201': content: application/json: schema: $ref: '#/components/schemas/SimulationSnapshot' description: Created '400': content: application/problem+json: examples: bad_request_body: $ref: '#/components/examples/bad_request_body' schema: $ref: '#/components/schemas/Error' description: Bad Request '401': $ref: '#/components/responses/Unauthorized' '403': content: application/problem+json: examples: auth_forbidden_simulation: $ref: '#/components/examples/auth_forbidden_simulation' schema: $ref: '#/components/schemas/Error' description: Forbidden '404': content: application/problem+json: examples: simulation_not_found: $ref: '#/components/examples/simulation_not_found' schema: $ref: '#/components/schemas/Error' description: Not Found '408': $ref: '#/components/responses/RequestTimeout' '409': content: application/problem+json: examples: clock_conflict: $ref: '#/components/examples/clock_conflict' idempotency_conflict: $ref: '#/components/examples/idempotency_conflict' simulation_observation_external: $ref: '#/components/examples/simulation_observation_external' simulation_stopped: $ref: '#/components/examples/simulation_stopped' schema: $ref: '#/components/schemas/Error' description: Conflict '413': $ref: '#/components/responses/PayloadTooLarge' '415': $ref: '#/components/responses/UnsupportedMediaType' '422': content: application/problem+json: examples: validation_idempotency_key: $ref: '#/components/examples/validation_idempotency_key' validation_snapshot_step: $ref: '#/components/examples/validation_snapshot_step' schema: $ref: '#/components/schemas/Error' description: Unprocessable Entity '500': $ref: '#/components/responses/InternalServerError' '503': content: application/problem+json: examples: auth_provider_unavailable: $ref: '#/components/examples/auth_provider_unavailable' internal_unavailable: $ref: '#/components/examples/internal_unavailable' simulation_environment_offline_request: $ref: '#/components/examples/simulation_environment_offline_request' schema: $ref: '#/components/schemas/Error' description: Service Unavailable security: - apiKeyAuth: [] components: schemas: CreateSimulationSnapshotRequest: additionalProperties: false examples: - at_step: 42 name: before-refund simulation_id: sim_01J8Z5X4K7M2N9P0Q1R2S3T4V6 properties: at_step: description: >- Completed step to save the state after. Omission saves the latest state. format: int64 maximum: 9007199254740991 minimum: 0 type: integer name: description: Snapshot name. maxLength: 128 minLength: 1 type: string simulation_id: description: ID of the running Simulation to save. minLength: 1 pattern: ^sim_[0-9A-HJKMNP-TV-Z]{26}$ type: string required: - simulation_id - name type: object SimulationSnapshot: additionalProperties: false examples: - at_step: 42 created_at: '2026-01-15T12:00:00Z' current_time: '2024-01-03T00:00:00Z' id: sns_01J8Z5X4K7M2N9P0Q1R2S3T4VC name: before-refund simulation_id: sim_01J8Z5X4K7M2N9P0Q1R2S3T4V8 simulator_id: smr_01J8Z5X4K7M2N9P0Q1R2S3T4V5 start_time: '2024-01-01T00:00:00Z' properties: at_step: description: >- Completed step the Snapshot saved, or null for the state that was latest when it was saved. format: int64 type: - integer - 'null' created_at: description: Snapshot creation time. format: date-time type: string current_time: description: >- Simulated time of the saved state, where a Simulation created from the Snapshot starts. format: date-time type: string id: description: Snapshot ID. pattern: ^sns_[0-9A-HJKMNP-TV-Z]{26}$ type: string name: description: Snapshot name. The ID is its identity, and names need not be unique. maxLength: 128 type: string simulation_id: description: >- ID of the Simulation the Snapshot saved, or null once that Simulation is deleted. pattern: ^sim_[0-9A-HJKMNP-TV-Z]{26}$ type: - string - 'null' simulator_id: description: >- ID of the Simulator a Simulation created from the Snapshot runs, at the digest its source pinned. pattern: ^smr_[0-9A-HJKMNP-TV-Z]{26}$ type: string start_time: description: Initial simulated time of a Simulation created from the Snapshot. format: date-time type: string required: - id - name - simulation_id - simulator_id - at_step - start_time - current_time - created_at type: object Error: additionalProperties: false properties: code: description: Stable machine-readable error code. minLength: 1 type: string detail: description: Safe human-readable error detail. minLength: 1 type: string validation: $ref: '#/components/schemas/SpecificationValidation' description: >- Safe specification diagnostics for a rejected build request, when available. required: - validation - code - detail type: object SpecificationValidation: additionalProperties: false properties: issues: description: Specification validation problems. At most 20 are returned. items: $ref: '#/components/schemas/SpecificationIssue' maxItems: 20 type: array required: - issues type: - object - 'null' SpecificationIssue: additionalProperties: false properties: code: description: Stable validation rule code. type: string kind: description: >- Whether the input is invalid, unsupported, incomplete, or has no specific diagnosis. enum: - invalid - unsupported - incomplete - unknown type: string location: description: Readable endpoint or field affected by this issue. maxLength: 512 type: string message: description: What needs attention at this location. type: string operation: description: >- Affected operation ID or method and path, when available. Empty for document-level issues. maxLength: 243 type: string suggestion: description: How to correct or address the problem. type: string required: - code - operation - location - kind - message - suggestion type: object examples: bad_request_body: value: code: bad_request detail: request body is invalid validation: null auth_forbidden_simulation: value: code: auth_forbidden detail: >- The Simulation with ID "sim_01J8Z5X4K7M2N9P0Q1R2S3T4V6" belongs to another workspace. validation: null simulation_not_found: value: code: simulation_not_found detail: No Simulation was found with ID "sim_01J8Z5X4K7M2N9P0Q1R2S3T4V6". validation: null clock_conflict: value: code: clock_conflict detail: A clock advance is active. validation: null idempotency_conflict: value: code: idempotency_conflict detail: >- The Idempotency-Key was already used with a different request. Use a new Idempotency-Key. validation: null simulation_observation_external: value: code: simulation_observation_external detail: >- The Simulation with ID "sim_01J8Z5X4K7M2N9P0Q1R2S3T4V6" runs in a customer environment. Continuous does not read or copy its state, so this operation is unavailable. validation: null simulation_stopped: value: code: simulation_stopped detail: >- The Simulation with ID "sim_01J8Z5X4K7M2N9P0Q1R2S3T4V6" is stopped. Start it before you retry this request. validation: null validation_idempotency_key: value: code: validation detail: Idempotency-Key must contain between 1 and 256 bytes validation: null validation_snapshot_step: value: code: validation detail: at_step does not identify a recorded step validation: null auth_provider_unavailable: value: code: auth_provider_unavailable detail: >- The authentication provider is unavailable. Retry the request after a short delay. validation: null internal_unavailable: value: code: internal_unavailable detail: >- The service is temporarily unavailable. Retry the request after a short delay. validation: null simulation_environment_offline_request: value: code: simulation_environment_offline detail: >- The runtime environment is offline. Retry the request once it reconnects. validation: null auth_invalid: value: code: auth_invalid detail: The authentication credential is invalid. validation: null auth_missing: value: code: auth_invalid detail: Authentication credentials are required. validation: null request_timeout: value: code: request_timeout detail: >- The request body was not received before the timeout. Retry the request. validation: null payload_too_large: value: code: payload_too_large detail: The request body exceeds the maximum allowed size. validation: null unsupported_media_type: value: code: unsupported_media_type detail: The request Content-Type is not supported. validation: null internal: value: code: internal detail: The server encountered an unexpected error. validation: null responses: Unauthorized: content: application/problem+json: examples: auth_invalid: $ref: '#/components/examples/auth_invalid' auth_missing: $ref: '#/components/examples/auth_missing' schema: $ref: '#/components/schemas/Error' description: Unauthorized RequestTimeout: content: application/problem+json: examples: request_timeout: $ref: '#/components/examples/request_timeout' schema: $ref: '#/components/schemas/Error' description: Request Timeout PayloadTooLarge: content: application/problem+json: examples: payload_too_large: $ref: '#/components/examples/payload_too_large' schema: $ref: '#/components/schemas/Error' description: Request Entity Too Large UnsupportedMediaType: content: application/problem+json: examples: unsupported_media_type: $ref: '#/components/examples/unsupported_media_type' schema: $ref: '#/components/schemas/Error' description: Unsupported Media Type InternalServerError: content: application/problem+json: examples: internal: $ref: '#/components/examples/internal' schema: $ref: '#/components/schemas/Error' description: Internal Server Error securitySchemes: apiKeyAuth: bearerFormat: Continuous API key description: >- Use a Continuous API key. Send it in the Authorization header as a Bearer token. scheme: bearer type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.