curl -X POST 'https://api.anthropic.com/v1/sessions/session-id/events?beta=true' \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H 'anthropic-version: 2023-06-01' \
  -H 'Content-Type: application/json' \
  -d '{
  "events": [
    {
      "type": "user.message",
      "content": [
        {
          "type": "text",
          "text": "Where is my order #1234?"
        }
      ]
    }
  ]
}'

# POST /v1/sessions/{session_id}/events?beta=true (Claude API)
Base URL: https://api.anthropic.com
Auth: x-api-key; Anthropic API key; required.
Status: Beta.
Request formats: application/json.
Last verified: 2026-10-20

> Send Events

## Critical Gotchas
* Authentication uses the `x-api-key` header and requests also require an `anthropic-version` header.
* The official OpenAPI URL is discovered from the SDK repository manifest and must remain under Anthropic's trusted Stainless storage prefix.

## cURL
curl -X POST 'https://api.anthropic.com/v1/sessions/session-id/events?beta=true' \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H 'anthropic-version: 2023-06-01' \
  -H 'Content-Type: application/json' \
  -d '{
  "events": [
    {
      "type": "user.message",
      "content": [
        {
          "type": "text",
          "text": "Where is my order #1234?"
        }
      ]
    }
  ]
}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| session_id | path | string | Yes | Path parameter session_id |
| events | body | object[] | Yes | Events to send to the `session`. |

## Response example
{"data":[{}]}

---
Need an API key? Get one at https://console.anthropic.com/settings/keys

POST

POST /v1/sessions/{session_id}/events?beta=true — Claude API

Beta

Anthropic API key (required); https://api.anthropic.com

Claude API

Send Events

Base URL: https://api.anthropic.com
Auth: x-api-key: <ANTHROPIC_API_KEY>
Last verified: 2026-10-20 · upstream hash matched

Actions Try in browser→

Agents: curl -H "Accept: text/markdown" this URL
→ 221 tokens · Vary: Accept

Critical gotchas

Authentication uses the x-api-key header and requests also require an anthropic-version header.

The official OpenAPI URL is discovered from the SDK repository manifest and must remain under Anthropic's trusted Stainless storage prefix.

cURL

curl -X POST 'https://api.anthropic.com/v1/sessions/session-id/events?beta=true' \  -H "x-api-key: $ANTHROPIC_API_KEY" \  -H 'anthropic-version: 2023-06-01' \  -H 'Content-Type: application/json' \  -d '{  "events": [    {      "type": "user.message",      "content": [        {          "type": "text",          "text": "Where is my order #1234?"        }      ]    }  ]}'

Parameters

Name	In	Type	Required	Description
session_id	path	string	Yes	Path parameter session_id
events	body	object[]	Yes	Events to send to the `session`.

Response 200 OK

{
  "data": [
    {
      "type": "user.message",
      "id": "sevt_011CZkZGOp0iBcp4kaQSihUmy",
      "content": [
        {
          "type": "text",
          "text": "Where is my order #1234?"
        }
      ],
      "processed_at": "2026-03-15T10:00:00Z"
    }
  ]
}

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