> ## Documentation Index > Fetch the complete documentation index at: https://docs.ochy.io/llms.txt > Use this file to discover all available pages before exploring further. # Start analysis > Upload a video file and start a biomechanical analysis. Returns a unique `video_id` that you use to poll for results. **Video requirements:** - Maximum file size: 30 MB - Maximum duration: 10 seconds - Accepted formats: MP4, MOV, AVI, WEBM See [example videos](/guides/example-videos) for sample input and output recordings. **Analysis types:** - `side_view` -- Running gait from the side. Produces biomechanical scores, metrics, joint angles, foot landing, and running style. - `back_view` -- Running gait from behind. Produces pronation/supination, pelvic drop, knee adduction, and gait cycle data. **Link to a subject:** Pass an optional `subject_id` to associate this analysis with a runner profile. You can then retrieve all analyses for that subject via `GET /analysis/subjects/{subject_id}`. See [subject management](/guides/subject-management) for the full workflow. **Webhooks (optional):** Set `notify_via_webhook=true` to receive progress and completion events on the HTTPS URL you registered with [`PUT /webhook`](/api-reference/webhooks/configure-webhook). Defaults to `false`. When `true`, a valid partner webhook must be configured and enabled. See [API keys and webhooks](/guides/webhooks-and-api-keys) for event types and payload format. One analysis credit is consumed per request. ## OpenAPI ````yaml /openapi.yaml post /analysis/start openapi: 3.0.1 info: title: Ochy Partner API version: 1.0.0 description: > The Ochy Partner API lets you integrate running biomechanical analysis into your application. Upload a video of a runner, receive detailed biomechanical metrics, joint angles, running style classification, and frame-by-frame position data. servers: - url: https://partner-api.ochy-prod.com description: Production security: - apiKey: [] paths: /analysis/start: post: tags: - Analysis summary: Start analysis description: > Upload a video file and start a biomechanical analysis. Returns a unique `video_id` that you use to poll for results. **Video requirements:** - Maximum file size: 30 MB - Maximum duration: 10 seconds - Accepted formats: MP4, MOV, AVI, WEBM See [example videos](/guides/example-videos) for sample input and output recordings. **Analysis types:** - `side_view` -- Running gait from the side. Produces biomechanical scores, metrics, joint angles, foot landing, and running style. - `back_view` -- Running gait from behind. Produces pronation/supination, pelvic drop, knee adduction, and gait cycle data. **Link to a subject:** Pass an optional `subject_id` to associate this analysis with a runner profile. You can then retrieve all analyses for that subject via `GET /analysis/subjects/{subject_id}`. See [subject management](/guides/subject-management) for the full workflow. **Webhooks (optional):** Set `notify_via_webhook=true` to receive progress and completion events on the HTTPS URL you registered with [`PUT /webhook`](/api-reference/webhooks/configure-webhook). Defaults to `false`. When `true`, a valid partner webhook must be configured and enabled. See [API keys and webhooks](/guides/webhooks-and-api-keys) for event types and payload format. One analysis credit is consumed per request. operationId: startAnalysis requestBody: required: true content: multipart/form-data: schema: type: object required: - video - analysis_type properties: video: type: string format: binary description: Video file to analyze (max 30 MB, 10 seconds). subject_id: type: string description: >- Optional subject ID to link this analysis to. See [subject management](/guides/subject-management) to create subjects. height: type: number description: Runner height in meters. default: 1.7 example: 1.75 weight: type: number description: Runner weight in kilograms. default: 70 example: 68 pace: type: string pattern: ^[0-9]{2}:[0-9]{2}$ description: > Running pace in `MM:SS` format. Required when `treadmill=true`. Optional when `treadmill=false` (pace is calculated automatically for overground running). example: '05:30' language: type: string enum: - en - fr - de - zh - ko - pt - es - it - ja default: en description: Language for analysis results and recommendations. example: en analysis_type: type: string enum: - side_view - back_view default: side_view description: Type of analysis to perform. example: side_view treadmill: type: boolean default: false description: >- Whether the runner is on a treadmill (`true`) or running outdoors (`false`). example: false full_body: type: boolean default: true description: > Include full body analysis. Only affects `back_view` analysis. When `false`, only pronation/supination analysis is performed. example: true notify_via_webhook: type: boolean default: false description: > When `true`, send progress and completion events for this analysis to the partner webhook URL configured via `PUT /webhook`. Requires a valid, enabled webhook. When `false` or omitted, no webhook events are sent for this analysis. example: false responses: '202': description: Analysis started. content: application/json: schema: $ref: '#/components/schemas/AnalysisStartResponse' example: message: 'Analysis started for ID: 3dde3402-94d7-462e-a784-9306207108dd' video_id: 3dde3402-94d7-462e-a784-9306207108dd '400': description: > Bad request -- invalid parameters, unsupported file type, video too long, or `notify_via_webhook=true` when no valid webhook is configured. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: detail: Video duration (15s) exceeds maximum allowed duration of 10s '401': description: Missing API key. content: application/json: schema: $ref: '#/components/schemas/AuthErrorResponse' example: detail: API Key is missing '402': description: Insufficient credits. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: detail: Insufficient credits to perform analysis code: insufficient_credits '403': description: Invalid API key. content: application/json: schema: $ref: '#/components/schemas/AuthErrorResponse' example: detail: Invalid API Key '413': description: File too large (max 30 MB). content: application/json: schema: $ref: '#/components/schemas/FileSizeErrorResponse' example: detail: File size exceeds the maximum allowed limit of 30 MB code: file_too_large '500': description: Internal server error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' components: schemas: AnalysisStartResponse: type: object properties: message: type: string example: 'Analysis started for ID: 3dde3402-94d7-462e-a784-9306207108dd' video_id: type: string description: Unique identifier for the analysis. Use this to poll for results. example: 3dde3402-94d7-462e-a784-9306207108dd ErrorResponse: type: object properties: detail: type: string example: Internal server error code: type: string description: Machine-readable error code (present on some errors). example: insufficient_credits AuthErrorResponse: type: object properties: detail: type: string example: API Key is missing FileSizeErrorResponse: type: object properties: detail: type: string example: File size exceeds the maximum allowed limit of 30 MB code: type: string example: file_too_large securitySchemes: apiKey: type: apiKey in: query name: apiKey description: Your API key, passed as a query parameter on every request. ````