VEvercel
Messages

Send Message (Async)

Changed on

Sends a new message to an existing chat and processes it in the background. Include designMode to apply element-scoped design edits; message may be omitted when edits are provided. Returns immediately with the assistant message ID. Poll GET /chats/:chatId/messages/:messageId and check finishReason to detect completion.

post/chats/{chatId}/messages/async

Request

  • Base URL
    https://api.v0.dev/v2
  • URL
    https://api.v0.dev/v2/chats/{chatId}/messages/async
  • Auth
    HTTP bearer

Path parameters

chatIdstring required

The unique identifier of the chat.

Request body

messagestring

The prompt or instruction to send to the model. May be omitted when designMode contains edits.

systemPromptstring

System-level context for the chat, such as frameworks or development environment details.

mcpServerIdsstring[]

MCP server IDs to enable. When omitted, uses default enabled servers.

Response

Acknowledgement that an async message has been queued.

messageIdstring required

ID of the assistant message that will receive the response. Poll GET /chats/:chatId/messages/:messageId and check finishReason for completion.

Changes

  • 467d24b4c224Revision changes
    • breaking

      removed the enum value v0-max of the request property / (media type: application/json)

    • breaking

      removed the enum value v0-max of the request property / (media type: application/x-www-form-urlencoded)

    • breaking

      removed the enum value v0-max of the request property / (media type: multipart/form-data)

    • breaking

      removed the enum value v0-max-fast of the request property / (media type: application/json)

    • breaking

      removed the enum value v0-max-fast of the request property / (media type: application/x-www-form-urlencoded)

    • breaking

      removed the enum value v0-max-fast of the request property / (media type: multipart/form-data)

    • breaking

      removed the enum value v0-mini of the request property / (media type: application/json)

    • breaking

      removed the enum value v0-mini of the request property / (media type: application/x-www-form-urlencoded)

    • breaking

      removed the enum value v0-mini of the request property / (media type: multipart/form-data)

    • breaking

      removed the enum value v0-pro of the request property / (media type: application/json)

    • breaking

      removed the enum value v0-pro of the request property / (media type: application/x-www-form-urlencoded)

    • breaking

      removed the enum value v0-pro of the request property / (media type: multipart/form-data)

    • breaking

      the / request property type changed from string to no type (media type: application/json)

    • info

      added subschema #1 subschema #2 to the / request property anyOf list (media type: application/json)

    • info

      added subschema #1 subschema #2 to the / request property anyOf list (media type: application/x-www-form-urlencoded)

    • info

      added subschema #1 subschema #2 to the / request property anyOf list (media type: multipart/form-data)

    • info

      the / request property type was generalized from string to no type (media type: application/x-www-form-urlencoded)

    • info

      the / request property type was generalized from string to no type (media type: multipart/form-data)

  • cca16477343aRevision changes
    • info

      added the new optional request property (media type: application/json)

    • info

      added the new optional request property (media type: application/x-www-form-urlencoded)

    • info

      added the new optional request property (media type: multipart/form-data)

    • info

      the request property became optional (media type: application/json)

    • info

      the request property became optional (media type: application/x-www-form-urlencoded)

    • info

      the request property became optional (media type: multipart/form-data)