Anthropic

Use Claude Sonnet 4, Claude Sonnet 4.5, and other Anthropic models with cagent.

Setup

# Set your API key
export ANTHROPIC_API_KEY="sk-ant-..."

Configuration

Inline

agents:
  root:
    model: anthropic/claude-sonnet-4-0

Named Model

models:
  claude:
    provider: anthropic
    model: claude-sonnet-4-0
    max_tokens: 64000

Available Models

Model Best For
claude-sonnet-4-5 Most capable, extended thinking
claude-sonnet-4-0 Strong coding, balanced performance

Thinking Budget

Anthropic uses integer token budgets (1024–32768). Defaults to 8192 with interleaved thinking enabled:

models:
  claude-deep:
    provider: anthropic
    model: claude-sonnet-4-5
    thinking_budget: 16384 # must be < max_tokens

Interleaved Thinking

Enabled by default. Allows tool calls during model reasoning for more integrated problem-solving:

models:
  claude:
    provider: anthropic
    model: claude-sonnet-4-5
    provider_opts:
      interleaved_thinking: false # disable if needed
ℹ️ Note

Anthropic thinking budget values below 1024 or greater than or equal to max_tokens are ignored (a warning is logged).

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