Begin a direct multipart upload session
Validates the declared name, MIME type, size, and per-part checksums, checks the workspace storage quota, opens a multipart upload against the object store, and returns the session with one presigned URL per part and an expiry. Requires a workspace member with the `files:write` permission. Refused when the storage backend does not support direct uploads, when the declared metadata or part layout is invalid, or when the workspace is over its storage quota. Send an `Idempotency-Key` header to make retries safe; a replay within the window returns the original response.
Authorization
apiKey Workspace API key created in Workspace settings → API keys. Scopes on the key bound what it can read and write.
In: header
Path Parameters
Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
Response Body
application/json
application/json
application/json
curl -X POST "https://example.com/v1/workspaces/string/assets/uploads" \ -H "Content-Type: application/json" \ -d '{ "name": "string", "mimeType": "string", "byteSize": 0, "partSize": 0, "parts": [ { "partNumber": 0, "checksumSha256": "string" } ] }'{ "data": { "id": "string", "expiresAt": "string", "parts": [ { "partNumber": 0, "checksumSha256": "string", "url": "string" } ] }}{ "_tag": "ApiNotFound", "error": "not_found", "message": "That item does not exist, or this key cannot see it.", "status": 404}{ "_tag": "ApiNotFound", "error": "not_found", "message": "That item does not exist, or this key cannot see it.", "status": 404}Branch an agent chat from a message
Creates a new chat seeded from the source chat's history: branching from a user message copies everything before it and returns that message's text as `seed` to re-run, while branching from an assistant message copies through it. An optional `model` overrides the branch's model. Requires a Clerk session for a workspace member with the `ai:write` permission and the `ai.agent.enabled` control switched on; an unknown chat or message is reported as not found.
Complete a direct multipart upload
Finalizes the multipart upload, verifies the stored object's size against what the session declared, and returns the resulting asset with its capability URL. Requires a workspace member with the `files:write` permission. A session that has expired, been aborted, or is completed with the wrong number of parts is rejected; completing a session that already finished returns the existing asset. Send an `Idempotency-Key` header to make retries safe; a replay within the window returns the original response.