Send Chat Message

POST

chat-messages

curl --request POST \
  --url https://{api_base_url}/chat-messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "inputs": {
    "city": "San Francisco"
  },
  "query": "What are the specs of the iPhone 13 Pro Max?",
  "response_mode": "streaming",
  "conversation_id": "",
  "user": "abc-123",
  "files": [
    {
      "type": "image",
      "transfer_method": "remote_url",
      "url": "https://cloud.dify.ai/logo/logo-site.png"
    }
  ]
}
'

{
  "event": "message",
  "task_id": "c3800678-a077-43df-a102-53f23ed20b88",
  "id": "b01a39de-3480-4f3e-9f1e-4841a80f8e5e",
  "message_id": "9da23599-e713-473b-982c-4328d4f5c78a",
  "conversation_id": "45701982-8118-4bc5-8e9b-64562b4555f2",
  "mode": "chat",
  "answer": "iPhone 13 Pro Max specs are listed here:...",
  "metadata": {
    "usage": {
      "prompt_tokens": 1033,
      "prompt_unit_price": "0.001",
      "prompt_price_unit": "0.001",
      "prompt_price": "0.0010330",
      "completion_tokens": 128,
      "completion_unit_price": "0.002",
      "completion_price_unit": "0.001",
      "completion_price": "0.0002560",
      "total_tokens": 1161,
      "total_price": "0.0012890",
      "currency": "USD",
      "latency": 0.7682376249867957
    },
    "retriever_resources": [
      {
        "position": 1,
        "dataset_id": "101b4c97-fc2e-463c-90b1-5261a4cdcafb",
        "dataset_name": "iPhone",
        "document_id": "8dd1ad74-0b5f-4175-b735-7d98bbbb4e00",
        "document_name": "iPhone List",
        "segment_id": "ed599c7f-2766-4294-9d1d-e5235a61270a",
        "score": 0.98457545,
        "content": "\"Model\",\"Release Date\",\"Display Size\",\"Resolution\",\"Processor\",\"RAM\",\"Storage\",\"Camera\",\"Battery\",\"Operating System\" \"iPhone 13 Pro Max\",\"September 24, 2021\",\"6.7 inch\",\"1284 x 2778\",\"Hexa-core (2x3.23 GHz Avalanche + 4x1.82 GHz Blizzard)\",\"6 GB\",\"128, 256, 512 GB, 1TB\",\"12 MP\",\"4352 mAh\",\"iOS 15\""
      }
    ]
  },
  "created_at": 1705407629
}

Authorizations

Authorization

string

header

required

API Key authentication. For all API requests, include your API Key in the Authorization HTTP Header, prefixed with Bearer. Example: Authorization: Bearer {API_KEY}. Strongly recommend storing your API Key on the server-side, not shared or stored on the client-side, to avoid possible API-Key leakage that can lead to serious consequences. Requests with a missing or invalid API key fail with HTTP 401 and error code unauthorized.

Body

application/json

Request body to send a chat message.

query

string

required

User input/question content.

inputs

object

required

Allows the entry of various variable values defined by the App. Contains key/value pairs. Refer to the user_input_form field in the Get App Parameters response to discover the variable names and types expected by your app.

user

string

required

User identifier, unique within the application. This identifier scopes data access — conversations, messages, and files are only visible when queried with the same user value.

response_mode

enum<string>

Mode of response return. streaming (recommended) uses SSE. blocking returns after completion (may be interrupted for long processes; not supported in Agent Assistant mode). Cloudflare timeout is 100 s. When omitted, defaults to blocking behavior. New Agent apps support streaming only; blocking returns 400 bad_request.

Available options:

streaming,

blocking

conversation_id

string

Conversation ID to continue a conversation. Pass the previous message's conversation_id. To start a new conversation, omit this field or pass an empty string. The response will return a conversation_id — pass it in subsequent messages to continue that conversation.

files

object[]

File list for multimodal understanding, including images, documents, audio, and video. To attach a local file, first upload it via Upload File and use the returned id as upload_file_id with transfer_method: local_file. Not supported for New Agent apps: file references are accepted but their contents are not processed.

Show child attributes

auto_generate_name

boolean

default:true

Auto-generate conversation title. If false, use the Rename Conversation API with auto_generate: true for async title generation.

workflow_id

string

Chatflow apps only. Specify a published workflow version ID to execute. If not provided, the latest published version is used.

Response

Successful response. The content type and structure depend on the response_mode parameter in the request.

If response_mode is blocking, returns application/json with a ChatCompletionResponse object.
If response_mode is streaming, returns text/event-stream with a stream of Server-Sent Events.

event

string

Event type, fixed as message.

task_id

string<uuid>

Task ID for request tracking and stop response API.

string<uuid>

Unique ID of this response event.

message_id

string<uuid>

Unique message ID. Use this as the message_id parameter when calling feedback or suggested questions endpoints.

conversation_id

string<uuid>

Conversation ID.

mode

string

App mode. chat for Chatbot apps, agent-chat for Agent apps, advanced-chat for Chatflow apps.

answer

string

Complete response content.

metadata

object

Metadata including usage and retriever resources.

Show child attributes

created_at

integer<int64>

Message creation timestamp (Unix epoch seconds).

Last modified on July 9, 2026

curl --request POST \
  --url https://{api_base_url}/chat-messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "inputs": {
    "city": "San Francisco"
  },
  "query": "What are the specs of the iPhone 13 Pro Max?",
  "response_mode": "streaming",
  "conversation_id": "",
  "user": "abc-123",
  "files": [
    {
      "type": "image",
      "transfer_method": "remote_url",
      "url": "https://cloud.dify.ai/logo/logo-site.png"
    }
  ]
}
'

{
  "event": "message",
  "task_id": "c3800678-a077-43df-a102-53f23ed20b88",
  "id": "b01a39de-3480-4f3e-9f1e-4841a80f8e5e",
  "message_id": "9da23599-e713-473b-982c-4328d4f5c78a",
  "conversation_id": "45701982-8118-4bc5-8e9b-64562b4555f2",
  "mode": "chat",
  "answer": "iPhone 13 Pro Max specs are listed here:...",
  "metadata": {
    "usage": {
      "prompt_tokens": 1033,
      "prompt_unit_price": "0.001",
      "prompt_price_unit": "0.001",
      "prompt_price": "0.0010330",
      "completion_tokens": 128,
      "completion_unit_price": "0.002",
      "completion_price_unit": "0.001",
      "completion_price": "0.0002560",
      "total_tokens": 1161,
      "total_price": "0.0012890",
      "currency": "USD",
      "latency": 0.7682376249867957
    },
    "retriever_resources": [
      {
        "position": 1,
        "dataset_id": "101b4c97-fc2e-463c-90b1-5261a4cdcafb",
        "dataset_name": "iPhone",
        "document_id": "8dd1ad74-0b5f-4175-b735-7d98bbbb4e00",
        "document_name": "iPhone List",
        "segment_id": "ed599c7f-2766-4294-9d1d-e5235a61270a",
        "score": 0.98457545,
        "content": "\"Model\",\"Release Date\",\"Display Size\",\"Resolution\",\"Processor\",\"RAM\",\"Storage\",\"Camera\",\"Battery\",\"Operating System\" \"iPhone 13 Pro Max\",\"September 24, 2021\",\"6.7 inch\",\"1284 x 2778\",\"Hexa-core (2x3.23 GHz Avalanche + 4x1.82 GHz Blizzard)\",\"6 GB\",\"128, 256, 512 GB, 1TB\",\"12 MP\",\"4352 mAh\",\"iOS 15\""
      }
    ]
  },
  "created_at": 1705407629
}

Guides

App APIs

Knowledge APIs

Authorizations

Body

Response