Send a message to an agent (A2A, non-streaming)

curl --request POST \
  --url https://{host}/v2/workspaces/slug:agent-factory/webhooks/v1/agents/{agentId}/messages/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "message": {
    "message_id": "msg-test-2",
    "role": "user",
    "parts": [
      {
        "text": "What is 2+2? Reply with just the number."
      }
    ]
  }
}
'

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    message: {
      message_id: 'msg-test-2',
      role: 'user',
      parts: [{text: 'What is 2+2? Reply with just the number.'}]
    }
  })
};

fetch('https://{host}/v2/workspaces/slug:agent-factory/webhooks/v1/agents/{agentId}/messages/send', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://{host}/v2/workspaces/slug:agent-factory/webhooks/v1/agents/{agentId}/messages/send"

payload = { "message": {
        "message_id": "msg-test-2",
        "role": "user",
        "parts": [{ "text": "What is 2+2? Reply with just the number." }]
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

{
  "error": {},
  "task": {
    "id": "<string>",
    "contextId": "<string>",
    "status": {
      "timestamp": "<string>",
      "message": {}
    },
    "output": {
      "messages": [
        {
          "message_id": "<string>",
          "contextId": "<string>",
          "taskId": "<string>",
          "parts": [
            {}
          ]
        }
      ]
    },
    "usage": {},
    "tool_calls": [
      {
        "name": "<string>",
        "arguments": {},
        "status": "<string>"
      }
    ]
  }
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

Messages

Send a message to an agent (A2A, non-streaming)

A2A-compliant message send. The body follows the A2A flat MessageSendParams shape - a message envelope with message_id, role, parts[], and an optional contextId. Parts are discriminated by field presence: TextPart (text), FilePart (url or raw), DataPart (data).

An always-on rate-limit floor (200/h per user) applies, plus any agent-configured limit. The HITL approval flow is supported and will park the task in input-required until resolved through /v1/agents/{agentId}/tasks/{taskId}/resolve.

Send the x-draft-mode: true header to bypass published_config resolution and exercise live (draft) configuration - owners and agent-factory writers only.

POST

agents

{agentId}

messages

send

Send a message to an agent (A2A, non-streaming)

curl --request POST \
  --url https://{host}/v2/workspaces/slug:agent-factory/webhooks/v1/agents/{agentId}/messages/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "message": {
    "message_id": "msg-test-2",
    "role": "user",
    "parts": [
      {
        "text": "What is 2+2? Reply with just the number."
      }
    ]
  }
}
'

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    message: {
      message_id: 'msg-test-2',
      role: 'user',
      parts: [{text: 'What is 2+2? Reply with just the number.'}]
    }
  })
};

fetch('https://{host}/v2/workspaces/slug:agent-factory/webhooks/v1/agents/{agentId}/messages/send', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://{host}/v2/workspaces/slug:agent-factory/webhooks/v1/agents/{agentId}/messages/send"

payload = { "message": {
        "message_id": "msg-test-2",
        "role": "user",
        "parts": [{ "text": "What is 2+2? Reply with just the number." }]
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

{
  "error": {},
  "task": {
    "id": "<string>",
    "contextId": "<string>",
    "status": {
      "timestamp": "<string>",
      "message": {}
    },
    "output": {
      "messages": [
        {
          "message_id": "<string>",
          "contextId": "<string>",
          "taskId": "<string>",
          "parts": [
            {}
          ]
        }
      ]
    },
    "usage": {},
    "tool_calls": [
      {
        "name": "<string>",
        "arguments": {},
        "status": "<string>"
      }
    ]
  }
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {}
}

Authorizations

Authorization

string

header

required

User-bound credential carrying an identity: either a session JWT or a user access token (at:*) generated from the user settings UI. Send as Authorization: Bearer <token>. Org API keys (iak_*) are not accepted here - they carry no user identity. Use the x-prismeai-api-key header instead (see OrgApiKeyAuth).

Headers

x-draft-mode

boolean

When true, the call exercises the agent's live (draft) config instead of published_config. Reserved for owners/writers.

Path Parameters

agentId

string

required

Maximum string length: 64

Body

application/json

message

object

required

A2A v0.3 flat message envelope.

Hide child attributes

message.message_id

string

Maximum string length: 256

message.role

enum<string>

Available options:

user,

agent

message.contextId

string

Maximum string length: 64

message.taskId

string

message.parts

object[]

Response

Completed task with the agent's reply.

error

object | null

task

object

Hide child attributes

task.id

string

task.contextId

string

task.status

object

Hide child attributes

task.status.state

enum<string>

A2A task state.

Available options:

working,

completed,

canceled,

failed,

input-required

task.status.timestamp

string

task.status.message

object

task.output

object

Hide child attributes

task.output.messages

object[]

Hide child attributes

task.output.messages.message_id

string

Maximum string length: 256

task.output.messages.role

enum<string>

Available options:

user,

agent

task.output.messages.contextId

string

Maximum string length: 64

task.output.messages.taskId

string

task.output.messages.parts

object[]

task.usage

object

task.tool_calls

object[]

Hide child attributes

task.tool_calls.name

string

task.tool_calls.arguments

object

task.tool_calls.status

string

⌘I

Introduction

Platform API

Agent Creator API

LLM Gateway API

Governance API

Knowledges API

Collections API

Send a message to an agent (A2A, non-streaming)

Authorizations

Headers

Path Parameters

Body

Response