> ## Documentation Index > Fetch the complete documentation index at: https://docs.siro.ai/llms.txt > Use this file to discover all available pages before exploring further. # Get a signed URL for uploading a recording > Generate signed upload and download URLs for an audio file. The upload URL can be used to upload the file directly to cloud storage. Generates a short-lived **signed upload URL** for an audio file plus a matching **download URL**. This is the first step of the direct-upload flow: upload your audio to cloud storage with `uploadUrl`, then pass `downloadUrl` as `fileUrl` to [Post recordings upload](/api-references/post-recordings-upload) to create the recording. ## Response fields | Field | Description | | --------------- | ---------------------------------------------------------------- | | `uploadUrl` | Signed URL to **`PUT`** the file body to (Google Cloud Storage). | | `uploadHeaders` | Headers you **must** send with the `PUT` — see below. | | `downloadUrl` | Pass this as `fileUrl` when creating the recording. | | `expiresAt` | When the signed URLs expire (ISO 8601). Upload before this time. | ## Required upload headers The values of `Content-Type` and `x-goog-content-length-range` are **baked into the signature** of `uploadUrl`. You must send them **exactly** as returned in `uploadHeaders`, or GCS rejects the upload with a `403 SignatureDoesNotMatch`. * **`Content-Type`** — the MIME type for the `fileType` you requested. Siro maps extensions as follows: | `fileType` | `Content-Type` | | ---------- | -------------- | | `mp3` | `audio/mpeg` | | `wav` | `audio/wav` | | `aac` | `audio/aac` | * **`x-goog-content-length-range`** — `0,`, where `` is the exact byte size you passed in the request. The uploaded body must fall within this range. ## Example upload ```bash theme={null} # 1. Request the signed URLs curl -X POST https://api.siro.ai/v1/core/recordings/signed-urls \ -H "x-siro-auth-token: $SIRO_OAUTH_TOKEN" \ -H "Content-Type: application/json" \ -d '{"fileType": "mp3", "fileSize": 1048576}' # Response: # { # "data": { # "uploadUrl": "https://storage.googleapis.com/...", # "uploadHeaders": { # "Content-Type": "audio/mpeg", # "x-goog-content-length-range": "0,1048576" # }, # "downloadUrl": "https://storage.googleapis.com/...", # "expiresAt": "2026-06-08T12:00:00.000Z" # } # } # 2. PUT the file to uploadUrl, echoing uploadHeaders verbatim curl -X PUT "$UPLOAD_URL" \ -H "Content-Type: audio/mpeg" \ -H "x-goog-content-length-range: 0,1048576" \ --data-binary @recording.mp3 ``` Then call [Post recordings upload](/api-references/post-recordings-upload) with `fileUrl` set to `downloadUrl`. ## OpenAPI ````yaml post /v1/core/recordings/signed-urls openapi: 3.0.0 info: version: 1.0.0 title: Recordings API servers: - url: https://api.siro.ai/ description: Siro API Gateway security: [] externalDocs: description: View the raw OpenAPI Specification in JSON format url: /openapi.json paths: /v1/core/recordings/signed-urls: post: summary: Get a signed URL for uploading a recording description: >- Generate signed upload and download URLs for an audio file. The upload URL can be used to upload the file directly to cloud storage. requestBody: content: application/json: schema: type: object properties: fileType: type: string description: File type (limited to mp3, aac, wav) fileSize: type: integer minimum: 0 exclusiveMinimum: true description: Size of the file in bytes required: - fileType - fileSize additionalProperties: false responses: '200': description: Get a signed URL for uploading a recording content: application/json: schema: type: object properties: data: type: object properties: uploadUrl: type: string description: Signed URL for uploading the file (PUT the body here). uploadHeaders: type: object properties: Content-Type: type: string description: >- MIME type for the file. Must be sent exactly when PUTting to `uploadUrl` (it is baked into the signature). x-goog-content-length-range: type: string description: >- Allowed upload size range `0,`. Must be sent exactly when PUTting to `uploadUrl` (it is baked into the signature). required: - Content-Type - x-goog-content-length-range description: >- Headers that must be included exactly as given when PUTting the file to `uploadUrl`. downloadUrl: type: string description: >- Pass this URL as `fileUrl` when creating the recording. expiresAt: type: string description: When the signed URLs expire (ISO 8601 date-time). required: - uploadUrl - uploadHeaders - downloadUrl - expiresAt cursor: anyOf: - type: string - type: number - nullable: true pageSize: type: number limit: type: number total: type: number nullable: true hasNextPage: type: boolean required: - data '400': description: Bad Request - Invalid parameters content: application/json: schema: type: object properties: error: type: string description: Error message required: - error '401': description: Unauthorized - User not authenticated content: application/json: schema: type: object properties: error: type: string description: Authentication error message required: - error '403': description: Forbidden - User does not have access content: application/json: schema: type: object properties: error: type: string description: Authorization error message required: - error '404': description: Not Found - Resource not found content: application/json: schema: type: object properties: error: type: string description: Resource not found error message required: - error '422': description: Unprocessable Content - The request failed validation checks content: application/json: schema: type: object properties: issues: type: array items: type: object properties: code: type: string expected: type: string received: type: string path: type: array items: anyOf: - type: string - type: number message: type: string required: - code - path - message name: type: string enum: - ZodError required: - issues - name '500': description: Internal Server Error content: application/json: schema: type: object properties: error: type: string description: Internal server error message required: - error security: - SiroAuthToken: [] components: securitySchemes: SiroAuthToken: type: apiKey in: header name: x-siro-auth-token description: >- OAuth access token for user-scoped requests (Authorization Code or machine-to-machine). Send header `x-siro-auth-token: `. Not an organization API key. x-default: ````