---
title: "Reply Mail"
method: POST
path: "/api/mail/reply"
tags: ["Notifications"]
---

# Reply Mail

`POST /api/mail/reply`

## Request

- Base URL: `https://api.agentstack.tech` (the document declares no server; this is the origin it was published from)
- URL: `https://api.agentstack.tech/api/mail/reply`
- Auth: one of:
  - API key in header `X-API-Key`
  - HTTP bearer

Reply to a thread (``thread_id``) or the last noticed letter. Same as messaging.inbox.reply.

## Headers

- `Idempotency-Key` string

## Request body

- object

## Response `200`

Successful Response

- unknown

## Other responses

- `400`: Bad Request
- `401`: Unauthorized
- `403`: Forbidden
- `404`: Not Found
- `409`: Conflict
- `422`: Validation Error
- `429`: Too Many Requests
- `500`: Internal Server Error

---

[API](https://skmtc.dev/agentstack/apis/agentstack-core-api.md) · [All operations](https://skmtc.dev/agentstack/apis/agentstack-core-api/llms.txt) · [OpenAPI document](https://skmtc.dev/agentstack/apis/agentstack-core-api/revisions/8ecf3406e74a?raw)