---
title: "A2A Send Task"
method: POST
path: "/a2a/tasks/send"
---

# A2A Send Task

`POST /a2a/tasks/send`

Receive a task from an external A2A agent.

Creates both an A2A task record and a corresponding Bernstein task,
linking them together for lifecycle synchronisation.

## Request body

- A2ATaskSendRequest — Body for POST /a2a/tasks/send - receive a task from an external A2A agent.
  - `sender` string, required
  - `message` string, required
  - `role` string

## Response `201`

Successful Response

- A2ATaskResponse — Serialised A2A task in responses. ``receipt`` carries the lineage receipt for an inbound task (#2609): the execution evidence a caller verifies offline with ``bernstein a2a verify --receipt``. It is ``None`` on read paths, and on write paths when the node could not provision receipt key material - an absent receipt means "unattested", which a caller should treat as unverified rather than trusted.
  - `id` string, required
  - `bernstein_task_id` string, nullable, required
  - `sender` string, required
  - `message` string, required
  - `status` string, required
  - `artifacts` A2AArtifactResponse[], required
    - `name` string, required
    - `content_type` string, required
    - `data` string, required
    - `created_at` number, required
  - `created_at` number, required
  - `updated_at` number, required
  - `receipt` object, nullable

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.net/sipyourdrink-ltd/apis/bernstein-task-server.md) · [All operations](https://skmtc.net/sipyourdrink-ltd/apis/bernstein-task-server/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sipyourdrink-ltd/bernstein-task-server/versions/86f514b4e920/schema)