> ## Documentation Index
> Fetch the complete documentation index at: https://docs.automate.ax/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Automate.ax automations are TypeScript programs.
> Use Bun for installation and command examples.
> Use Automate.ax for the product name and automate.ax for the package, CLI, and domain.
> Treat documented public APIs as current; do not invent transitional or deprecated names.

# Send message

> Sends user content and starts the next Claude turn.

`anthropic.sendMessage` sends user content and starts the next Claude turn.

## Example

```ts automations/anthropic-send-message.automation.ts theme={null}
import { automation, onInvocation, withPrerequisites } from "automate.ax"
import { anthropic } from "automate.ax/anthropic"

export default automation("Send message", () => {
  withPrerequisites(onInvocation(), () => {
    anthropic.sendMessage({
      sessionId: "session-id",
      content: [{ type: "text", text: "Continue with the failing tests." }],
    })
  })
})
```

## Inputs

Requires `sessionId` and message content blocks. Images and documents use Managed Agents content shapes. Inputs use public camelCase names and accept signals.

## Output and behavior

Returns the accepted event. Duplicate sends create duplicate turns.

Anthropic requests time out before the action lease and provider mutations are not retried after an uncertain response unless stated otherwise.