Anthropic API

Loom can talk directly to https://api.anthropic.com/v1/messages using an Anthropic API key. This is provider-direct (no Claude Code CLI in the loop) and gives you live token streaming.

When to use it

Use the direct API when:

• You want streamed tokens.
• You want to use a model that isn't yet exposed through the Claude Code CLI's -p mode.
• You're running on a machine without claude on PATH.

For day-to-day work the Claude Code provider is preferred — it uses your existing OAuth login (no key management) and exposes the full sub-agent system.

Setup

1. Get an API key from console.anthropic.com.
2. Open Settings → Advanced.
3. Paste the key into the Anthropic API Key field.
4. Click Save.

The key is stored in macOS Keychain under service com.chasesims.Loom, account anthropic_api_key. See Keychain keys.

Wire format

The provider sends:

POST https://api.anthropic.com/v1/messages
content-type: application/json
x-api-key: <your key>
anthropic-version: 2023-06-01

with stream: true. SSE events of type content_block_delta with delta.type == "text_delta" are emitted as tokens.

Default model

claude-opus-4-7, max tokens 4096. Both are tunable in code (AnthropicProvider) but not yet exposed in Settings — open an issue if you need that today.

Cost

Direct API calls bill against your Anthropic account, separate from any Claude Code subscription. The Usage indicator in Loom's top bar reflects Claude Code's local OAuth quota — it does not track direct-API usage.