Anthropic Agents SDK (Claude Subscription)

Provider value: anthropic-agents-sdk

Use your Claude Pro or Max subscription to run ra agents instead of paying per-token API costs. This wraps the Anthropic Agent SDK as a model interface — ra owns all context engineering, tool execution, and the agent loop.

When to use this vs the anthropic provider

Use anthropic if you have an API key and want per-token billing. Use anthropic-agents-sdk if you want to use your Claude subscription instead.

Setup

Step 1: Install the Claude CLI

The provider requires the Claude CLI installed and authenticated:

# Install
npm install -g @anthropic-ai/claude-code

# Authenticate (opens browser)
claude login

Step 2: Run

ra --provider anthropic-agents-sdk "Hello"

No API key or environment variables needed — the provider uses your Claude CLI subscription.

Environment variables

None required. Authentication is handled by the Claude CLI.

Models

Available models depend on your Claude subscription tier:

Model	Notes
claude-sonnet-4-6	Default. Fast and capable
claude-opus-4-6	Most capable

ra --provider anthropic-agents-sdk --model claude-opus-4-6 "Design a system"

Extended thinking

Supports extended thinking via the --thinking flag:

ra --provider anthropic-agents-sdk --thinking high "Design a distributed cache"

Config file

agent:
  provider: anthropic-agents-sdk
  model: claude-sonnet-4-6

How it works

1. Each stream() call spawns a fresh Claude CLI subprocess via the SDK's query() function
2. ra's conversation history is serialized as XML-tagged text (<user>, <assistant>, <tool_result>)
3. Tools are registered as MCP schemas with no-op handlers — the model sees them but ra executes them
4. maxTurns=1 ensures the SDK does exactly one model call per turn, then returns control to ra
5. All SDK context features (memory, dreams, git instructions, session persistence) are disabled — ra owns context

Limitations

• Requires the Claude CLI installed and on PATH
• Subscription rate limits apply
• Slightly higher latency per turn due to subprocess spawning

See also

• Anthropic provider — for API key-based access
• Providers overview — switching between providers
• Configuration — provider credentials reference