> ## Documentation Index > Fetch the complete documentation index at: https://docs.valar.space/llms.txt > Use this file to discover all available pages before exploring further. # Generate OEM from a state vector > Generate CCSDS OEM v2.0 format ephemerides from a state vector with specified time range, reference frame, time system, and optional covariance propagation. Maximum time span is 30 days. ## OpenAPI ````yaml https://api.valar.space/api-docs/mintlify post /operations/state-vectors/{id}/generate-oem openapi: 3.0.1 info: contact: email: api@valar.space name: Valar Space url: https://valar.space description: >-

Welcome to the documentation for the Valar Operations API, here are some quick tips if you just landed!

  1. The top level elements are the Resources accessible via the API and the different queries used to interact with each resource via the appropriate HTTP method call.
  2. You can expand each method to get further information on the expected input parameters and the different responses that can be received.
  3. For both the input parameters and responses, an Example is present for clarification.
  4. For further details, the example snipped can be switched to Schema view, where a detailed explanation of each element can be found.
  5. The Try it out button can be used to call the API directly from the documentation page, which allows for some easy testing and also provides the equivalent 'curl' command line code for easy portability of the call execution.
  6. Before starting, remember to use the token endpoint and activate the token with the Authorize button.
title: API Documentation version: 1.0.0 servers: - url: / description: Default Server URL - url: https://api.valar.space description: API Server security: - apiKeyAuth: [] tags: - description: >- Operations for managing state vectors — listing, importing, exporting, and deleting spacecraft state data name: State Vectors paths: /operations/state-vectors/{id}/generate-oem: post: tags: - State Vectors summary: Generate OEM from a state vector description: >- Generate CCSDS OEM v2.0 format ephemerides from a state vector with specified time range, reference frame, time system, and optional covariance propagation. Maximum time span is 30 days. operationId: generateOem parameters: - description: State vector display ID example: SV-123 in: path name: id required: true schema: type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/OemGenerationRequest' required: true responses: '200': content: text/plain: example: |- CCSDS_OEM_VERS = 2.0 CREATION_DATE = 2024-06-15T12:30:00 ORIGINATOR = VALAR ... schema: type: string description: OEM file generated successfully '400': content: application/json: example: timestamp: '2025-01-15T10:30:00.000Z' status: 400 error: Bad Request message: Time span cannot exceed 30 days path: /operations/state-vectors/{id}/generate-oem schema: $ref: '#/components/schemas/ErrorResponse' description: Invalid request parameters or validation errors '401': content: application/json: schema: $ref: '#/components/schemas/BearerTokenErrorResponse' description: Not authenticated — missing or invalid bearer token '403': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Insufficient permissions '404': content: application/json: example: timestamp: '2025-01-15T10:30:00.000Z' status: 404 error: Not Found message: 'StateVector not found with id: SV-999' path: /operations/state-vectors/SV-999/generate-oem schema: $ref: '#/components/schemas/ErrorResponse' description: State vector not found '422': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: >- Orbit is stale (ORBIT_STALE) — the generate-oem carve-out keeps its 422 and is never acknowledged '500': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Internal error during OEM generation components: schemas: OemGenerationRequest: required: - finalDate - initialDate - referenceFrame - timeBetweenPoints - timeSystem type: object properties: covarianceFrame: type: string description: Covariance reference frame for OEM covariance matrices example: RTN enum: - RTN - TNW covarianceFrameValid: type: boolean dateRangeValid: type: boolean finalDate: type: string description: End date for ephemeris generation in ISO-8601 format format: date-time example: '2024-01-02T00:00:00Z' includeCovariance: type: boolean description: Include covariance matrices in the OEM output example: false default: false initialDate: type: string description: Start date for ephemeris generation in ISO-8601 format format: date-time example: '2024-01-01T00:00:00Z' referenceFrame: type: string description: Reference frame for position and velocity vectors example: GCRF enum: - GCRF - EME2000 - ITRF - TOD - MOD - TEME timeBetweenPoints: maximum: 86400 minimum: 60 type: integer description: Time step between ephemeris points in seconds format: int32 example: 60 timeSpanValid: type: boolean timeSystem: type: string description: Time system for ephemeris timestamps example: UTC enum: - UTC - TAI - TT - TDB - TCG - TCB - GPS description: >- Request parameters for OEM generation with configurable propagation settings ErrorResponse: type: object properties: details: type: object additionalProperties: type: object description: Structured error details with scenario-specific context fields nullable: true description: Structured error details with scenario-specific context fields nullable: true error: type: string description: HTTP status reason phrase or error category example: Bad Request fieldErrors: type: object additionalProperties: type: string description: >- Per-field validation error messages, present only for validation errors nullable: true description: >- Per-field validation error messages, present only for validation errors nullable: true message: type: string description: Detailed error message example: Validation failed path: type: string description: The request path where the error occurred example: /measurements status: type: integer description: The HTTP status code format: int32 example: 400 timestamp: type: string description: The timestamp when the error occurred format: date-time example: '2025-11-14T10:15:30.123Z' BearerTokenErrorResponse: type: object properties: error: type: string description: OAuth 2.0 error code example: invalid_token error_description: type: string description: Human-readable error description example: An error occurred while attempting to decode the Jwt description: OAuth 2.0 Bearer Token error response (RFC 6750) securitySchemes: apiKeyAuth: description: 'API Key (format: vsp_sk_...)' scheme: bearer type: http ````