> ## Documentation Index > Fetch the complete documentation index at: https://dev.chief.bot/llms.txt > Use this file to discover all available pages before exploring further. # Create Asset Upload > Step 1 of 3. Reserves an asset record and mints a signed upload URL. The client must then PUT the exact bytes to `upload_url` (step 2) and call `POST /v1/assets/{id}/complete` (step 3) to hand off to the ingest pipeline. When the request includes the file's hex-encoded `md5` and content with that digest already exists in the project, the server skips the upload: it returns `200` with `already_exists: true`, the existing `asset_id`, and its current `status`, and omits the upload fields. A first upload (or a prior upload that failed ingest) returns `201` with the signed-URL fields. ## OpenAPI ````yaml /openapi.yaml post /v1/assets openapi: 3.0.3 info: title: Chief Public API version: 1.0.0 contact: name: Chief Support url: https://chief.bot description: | Chief's public REST API for programmatic access to chats and assets. All endpoints are authenticated with a Personal Access Token (PAT) sent in the `X-API-Key` header. PATs are minted out-of-band from the Chief settings UI. All endpoints that touch project-scoped resources require the `X-Project-Id` header. Missing or invalid project IDs respond with HTTP 400 and the error code `publicapi.tenancy.project.missing`. ## Error envelope Every error response uses the same JSON envelope: ```json { "code": "publicapi.auth.invalid", "humane": "The provided API key is invalid or has been revoked.", "statusCode": 401 } ``` `code` is a stable, dotted, lowercase identifier suitable for client-side i18n and analytics. `humane` is plain English safe to surface to end users. `statusCode` mirrors the HTTP status. ## Chat workflow — kickoff + poll Chats are asynchronous in v1. Callers need to poll the per-message endpoint until the content they need is present. 1. `POST /v1/chats` with `{prompt}`. The server kicks off the workflow and returns `{chat_id, message_id, created_at}` immediately. `message_id` is the message you'll poll. 2. `POST /v1/chats/{chat_id}/messages` with `{prompt}` to continue an existing chat — appends a new turn and returns `{message_id, created_at}`. 3. `GET /v1/chats/{chat_id}/messages/{message_id}` to read the message. While the workflow is still writing, `prompt` and `response` are omitted; once written they're present. Treat the appearance of `response` as the signal that the assistant has produced output. 4. `GET /v1/chats/{chat_id}` returns chat-level metadata only (`modified_at`). It does not carry messages. 5. `GET /v1/chats/{chat_id}/messages` lists every message's id + `created_at` (no content); clients fetch one message at a time via `GET /v1/chats/{chat_id}/messages/{mid}` for the prompt + response body. ## Asset workflow — three-step upload Assets are uploaded directly to blob storage via a signed URL. The flow is: 1. `POST /v1/assets` with `{filename, mime_type}`, optionally including the hex-encoded `md5` of the file. When `md5` matches content already in the project the server returns `200` with `already_exists: true` and no upload URL — skip to fetching the asset. Otherwise it returns `201` with `{asset_id, upload_url, upload_method:"PUT", upload_headers, expires_at}`. 2. `PUT` the file bytes to `upload_url`, applying every header in `upload_headers` verbatim. The URL is valid until `expires_at`. 3. `POST /v1/assets/{asset_id}/complete` with an empty body to hand the asset off to the ingest pipeline. The server reads the uploaded object's size and MD5 from blob storage at this step. The response carries the current `AssetResponse`; clients poll until `status` is `ready` or `failed`. servers: - url: '{baseUrl}' description: Chief variables: baseUrl: default: https://api.storytell.ai description: Base URL of the deployment serving the API. security: - apiKey: [] tags: - name: Chats description: Public chat lifecycle — kickoff, list, fetch. - name: Assets description: Public asset upload + ingest lifecycle. - name: Labels description: Public label CRUD and asset-label attachment. - name: Actions description: Public action CRUD plus enable/disable. - name: Sessions description: Public recording-session listing and CRUD. - name: Skills description: Public skill CRUD plus enable/disable. - name: Memories description: Public memory CRUD. - name: Projects description: Public project create/edit, membership, and invitations. paths: /v1/assets: post: tags: - Assets summary: Create Asset Upload description: | Step 1 of 3. Reserves an asset record and mints a signed upload URL. The client must then PUT the exact bytes to `upload_url` (step 2) and call `POST /v1/assets/{id}/complete` (step 3) to hand off to the ingest pipeline. When the request includes the file's hex-encoded `md5` and content with that digest already exists in the project, the server skips the upload: it returns `200` with `already_exists: true`, the existing `asset_id`, and its current `status`, and omits the upload fields. A first upload (or a prior upload that failed ingest) returns `201` with the signed-URL fields. operationId: createAsset parameters: - $ref: '#/components/parameters/XProjectId' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateAssetRequest' example: filename: q2-launch-deck.pdf mime_type: application/pdf responses: '200': description: | Content dedup hit. An asset with this `md5` already exists in the project; no upload is needed. content: application/json: schema: $ref: '#/components/schemas/CreateAssetResponse' example: asset_id: asset_d8aad64dib2c7m3ae7j1 already_exists: true status: ready '201': description: Upload URL minted. content: application/json: schema: $ref: '#/components/schemas/CreateAssetResponse' example: asset_id: asset_d8aad64dib2c7m3ae7j1 already_exists: false upload_url: >- https://storage.googleapis.com/storytell-assets/asset_d8aad64dib2c7m3ae7j1?X-Goog-Signature=... upload_method: PUT upload_headers: Content-Type: application/pdf expires_at: '2026-05-23T10:30:00Z' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '500': $ref: '#/components/responses/InternalServerError' security: - apiKey: [] components: parameters: XProjectId: in: header name: X-Project-Id required: true schema: type: string pattern: ^project_[a-z0-9]{20}$ example: project_d8a4td4dib27i4beefb0 description: | Project identifier scoping the request. Required on every project-scoped public endpoint. Missing or malformed values respond with HTTP 400 and code `publicapi.tenancy.project.missing`. schemas: CreateAssetRequest: type: object required: - filename - mime_type properties: filename: type: string description: Original filename. Used for display and ingest hints. mime_type: type: string description: RFC 6838 media type of the upload. md5: type: string description: | Hex-encoded md5 of the file. Optional. When supplied and content with this digest already exists in the project, the server returns the existing asset instead of a new upload URL. CreateAssetResponse: type: object required: - asset_id - already_exists description: | Two shapes share this schema. A new upload (`201`) carries the signed-URL fields the client uses to PUT the bytes. A content-dedup hit (`200`) sets `already_exists` to true, reports the existing asset's `status`, and omits the upload fields. properties: asset_id: type: string pattern: ^asset_[a-z0-9]{20}$ already_exists: type: boolean description: | True when an asset with the request's `md5` already existed; the upload fields are then absent. status: $ref: '#/components/schemas/AssetStatus' upload_url: type: string format: uri upload_method: type: string example: PUT description: | HTTP method to use for the upload. `PUT` today; resumable multi-part uploads may add new values without breaking the existing PUT flow. upload_headers: type: object additionalProperties: type: string description: | Headers the client MUST apply verbatim to the upload request. Includes `Content-Type`. expires_at: type: string format: date-time AssetStatus: type: string enum: - uploaded - ingesting - ready - failed description: | Asset lifecycle. Progresses uploaded -> ingesting -> ready, or terminates at failed on any extraction error. Error: type: object required: - code - statusCode properties: code: type: string pattern: ^[a-z][a-z0-9_]*(\.[a-z0-9_]+)+$ description: | Stable dotted, lowercase identifier, namespaced by domain and operation (`..`). Suitable for client-side i18n keys and analytics. Codes are additive; existing codes are never reworded. example: publicapi.auth.invalid humane: type: string description: Plain-English message safe to display to end users. example: The provided API key is invalid or has been revoked. statusCode: type: integer minimum: 400 maximum: 599 description: | Mirror of the HTTP status code. (Field name is camelCase here only — owned by `nutils.Error` across the platform.) example: 401 responses: BadRequest: description: Malformed request, validation failure, or missing tenancy header. content: application/json: schema: $ref: '#/components/schemas/Error' examples: missingProject: summary: Missing X-Project-Id value: code: publicapi.tenancy.project.missing humane: X-Project-Id header is required. statusCode: 400 Unauthorized: description: Missing, malformed, or revoked credentials. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: publicapi.auth.invalid humane: The provided API key is invalid or has been revoked. statusCode: 401 InternalServerError: description: Unexpected server error. content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: apiKey: type: apiKey in: header name: X-API-Key description: | Personal Access Token, sent verbatim as `pat_<32 chars>`. PATs are minted from the Chief settings UI. ````