> ## Documentation Index > Fetch the complete documentation index at: https://docs.tied.com/llms.txt > Use this file to discover all available pages before exploring further. # Reserve a direct upload for a conversation > Reserves storage for a file and returns a one-time URL to `PUT` the bytes to. Two steps, not one: 1. `POST` here with the file's name, size, MIME type and base64 MD5 checksum. 2. `PUT` the bytes to `direct_upload.url` with the headers it gives you. The upload is rejected if the bytes disagree with the size or checksum you declared. Then send `signed_id` as the attachment when you create the message. Prefer `POST /upload` if you just want Tied to store a file for you — it takes the file directly and hands back a `blob_id` in one call. Direct upload exists so a large file can go straight to storage without passing through the application. ## OpenAPI ````yaml /api-reference/openapi.json post /api/v1/accounts/{account_id}/conversations/{conversation_id}/direct_uploads openapi: 3.0.4 info: title: Tied API description: >- The Tied REST API. Three families of endpoint, each with its own credential: **Application** for everything inside an account, **Platform** for provisioning accounts and users, and **Client** for acting as a contact from your own surface. version: 1.1.0 termsOfService: https://tied.com/legal contact: email: hello@tied.com license: name: MIT License url: https://opensource.org/licenses/MIT servers: - url: https://app.tied.com description: Tied cloud security: [] tags: - name: Account AgentBots description: Account-specific Agent Bots - name: Agents description: Agent management APIs - name: Canned Responses description: Pre-defined responses for common queries - name: Contacts description: Contact management APIs - name: Contact Labels description: Manage contact labels - name: Conversation Assignments description: Manage conversation assignments - name: Conversation Labels description: Manage conversation labels - name: Conversations description: Conversation management APIs - name: Custom Attributes description: Custom fields for contacts and conversations - name: Custom Filters description: Saved filters for conversations - name: Inboxes description: Communication channels setup - name: Integrations description: Third-party integrations - name: Messages description: Message management APIs - name: Profile description: User profile APIs - name: Reports description: Analytics and reporting APIs - name: Teams description: Team management APIs - name: Webhooks description: Event notification webhooks - name: Automation Rule description: Workflow automation rules - name: Help Center description: Knowledge base management - name: Contacts API description: Public contact APIs - name: Conversations API description: Public conversation APIs - name: Messages API description: Public message APIs - name: CSAT Survey Page description: Customer satisfaction survey - name: Account description: >- The authenticated user's own account — read and update account settings. Distinct from the Platform family's **Accounts**, which provisions accounts across an installation. - name: Audit Logs description: Read the account's audit trail - name: Inbox API description: Public inbox lookup by channel identifier - name: Labels description: >- Create and manage the account's labels. Applying one to a conversation or contact is a separate endpoint under those resources. - name: Macros description: >- Saved multi-step actions an agent — or an integration — can run against one or more conversations. - name: Campaigns description: Ongoing website campaigns and one-off SMS and WhatsApp sends. - name: Contact Notes description: Internal notes on a contact. Never visible to the contact. - name: Help Center Categories description: Categories group a portal's articles, one tree per allowed locale. - name: Help Center Articles description: The articles a portal publishes, and their draft and archived states. - name: Summary Reports description: Per-agent, per-team, per-inbox and per-label totals for a period, as JSON. - name: Live Reports description: Right-now queue counts. No date range — these describe the present. - name: CSAT description: >- The satisfaction ratings contacts have submitted, and the metrics computed from them. - name: Notifications description: >- The per-user notification feed, its read and snooze state, and the settings that decide what lands in it. - name: Conversation Participants description: >- The agents watching a conversation. Participants get notified about it without being assigned to it. - name: Draft Messages description: >- The unsent reply held for a conversation. Stored in Redis, one per conversation. - name: Search description: >- One search service across conversations, contacts, messages and Help Center articles. - name: Dashboard Apps description: Embedded pages that appear as a tab beside a conversation. - name: Assignment Policies description: How conversations are handed out, and which inbox uses which policy. - name: Files description: Storing a file so another endpoint can attach it. - name: Bot Flows description: >- Scripted conversation flows, their versions, and the publish and rollback that move between them. - name: Billing description: >- Credit balance, usage, invoices, spend controls and the provider-hosted payment flows. - name: AMB Templates description: >- Saved Apple Messages primitive payloads an agent can reuse from the composer. - name: AMB Onboarding description: The in-flight Apple Messages for Business registration for an account. - name: Widget Session description: Starting a widget session and reading the visitor it belongs to. - name: Widget Conversation description: The visitor's conversation and its messages. - name: Widget Context description: Campaigns, agents, labels, events and uploads for a widget session. - name: CSAT Survey description: The public, unauthenticated survey a contact answers from a link. - name: Workspace description: Scheduling and cancelling deletion of the whole workspace. paths: /api/v1/accounts/{account_id}/conversations/{conversation_id}/direct_uploads: parameters: - $ref: '#/components/parameters/account_id' - $ref: '#/components/parameters/conversation_id' post: tags: - Files summary: Reserve a direct upload for a conversation description: >- Reserves storage for a file and returns a one-time URL to `PUT` the bytes to. Two steps, not one: 1. `POST` here with the file's name, size, MIME type and base64 MD5 checksum. 2. `PUT` the bytes to `direct_upload.url` with the headers it gives you. The upload is rejected if the bytes disagree with the size or checksum you declared. Then send `signed_id` as the attachment when you create the message. Prefer `POST /upload` if you just want Tied to store a file for you — it takes the file directly and hands back a `blob_id` in one call. Direct upload exists so a large file can go straight to storage without passing through the application. operationId: create-conversation-direct-upload requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/direct_upload_payload' example: blob: filename: orders.csv byte_size: 27 checksum: janaQDJaHWRN47FY/qJ9kQ== content_type: text/csv responses: '200': description: Success content: application/json: schema: $ref: '#/components/schemas/direct_upload_blob' example: id: 23 key: 10jxqa9sxnw873rkmoutu49u0h4b filename: orders.csv content_type: text/csv metadata: {} byte_size: 27 checksum: janaQDJaHWRN47FY/qJ9kQ== created_at: '2026-09-21T05:13:10.967Z' service_name: local attachable_sgid: >- eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaEpJalZuYVdRNkx5OWphR0YwZDI5dmRDOUJZM1JwZG1WVGRHOXlZV2RsT2pwQ2JHOWlMekl6UDJWNGNHbHlaWE5mYVc0R09nWkZWQT09IiwiZXhwIjpudWxsLCJwdXIiOiJhdHRhY2hhYmxlIn19--EXAMPLE signed_id: >- eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBIQT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--EXAMPLE direct_upload: url: >- https://app.tied.com/rails/active_storage/blobs/proxy/EXAMPLE/asset.png headers: Content-Type: text/csv '403': description: Access denied content: application/json: schema: $ref: '#/components/schemas/error_message' '404': description: Not found content: application/json: schema: $ref: '#/components/schemas/error_message' '422': description: Validation failed content: application/json: schema: $ref: '#/components/schemas/error_validation' security: - userApiKey: [] components: parameters: account_id: in: path name: id schema: type: integer required: true description: The numeric ID of the account conversation_id: in: path name: conversation_id schema: type: integer required: true description: The numeric ID of the conversation schemas: direct_upload_payload: type: object required: - blob properties: blob: type: object required: - filename - byte_size - checksum - content_type description: >- Describe the file before sending it. All four fields are required, and the subsequent PUT is rejected if the bytes disagree with `byte_size` or `checksum`. properties: filename: type: string description: The file name. example: orders.csv byte_size: type: integer description: Size in bytes. example: 27 checksum: type: string description: Base64-encoded MD5 of the file contents. example: janaQDJaHWRN47FY/qJ9kQ== content_type: type: string description: MIME type. example: text/csv direct_upload_blob: type: object description: >- The stored blob plus the one-time URL to PUT the bytes to. This is Rails' ActiveStorage direct-upload response, passed through unchanged. properties: id: type: integer description: The blob's numeric ID. key: type: string description: The storage key. filename: type: string description: The filename you declared. content_type: type: string description: The content type you declared. byte_size: type: integer description: >- The size you declared. The upload is rejected if the bytes do not match it. checksum: type: string description: >- The base64 MD5 you declared. The upload is rejected if the bytes do not match it. metadata: type: object description: Metadata ActiveStorage derives once the bytes arrive. service_name: type: string description: Which storage service holds it. created_at: type: string description: ISO-8601 timestamp. signed_id: type: string description: What you send as the attachment reference when creating the message. attachable_sgid: type: string description: Signed global ID for the blob, used by rich-text attachment flows. direct_upload: type: object description: Where and how to send the bytes. properties: url: type: string description: >- One-time URL to `PUT` the file to. Short-lived — upload immediately rather than storing it. headers: type: object description: >- Headers the `PUT` must carry, including the content type and checksum. error_message: type: object description: >- The shape returned by `render_unauthorized`, `render_not_found_error` and `render_could_not_create_error`. properties: error: type: string description: A single human-readable message. example: Resource could not be found required: - error error_validation: type: object description: >- The shape returned by `render_record_invalid` when a model validation fails. properties: message: type: string description: The record's full error messages, comma-joined. example: Url has already been taken attributes: type: array description: The attributes that failed validation. items: type: string example: - url required: - message securitySchemes: userApiKey: type: apiKey in: header name: api_access_token description: >- This token can be obtained by visiting the profile page or via rails console. Provides access to endpoints based on the user permissions levels. This token can be saved by an external system when user is created via API, to perform activities on behalf of the user. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.