Configuration

Feynman stores all configuration and state under ~/.feynman/. This directory is created on first run and contains settings, authentication tokens, session history, and installed packages.

Directory structure

~/.feynman/
├── settings.json       # Core configuration
├── web-search.json     # Web search routing config
├── auth/               # OAuth tokens and API keys
├── sessions/           # Persisted conversation history
└── packages/           # Installed optional packages

The settings.json file is the primary configuration file. It is created by feynman setup and can be edited manually. A typical configuration looks like:

{
  "defaultProvider": "anthropic",
  "defaultModel": "claude-sonnet-4-20250514",
  "defaultThinkingLevel": "medium"
}

Model configuration

The defaultProvider and defaultModel fields set which model is used when you launch Feynman without the --model flag. You can change them via the CLI:

feynman model set anthropic/claude-opus-4-20250514

To see all models you have configured:

feynman model list

Only authenticated/configured providers appear in feynman model list. If you only see OpenAI models, it usually means only OpenAI auth is configured so far.

To add another provider, authenticate it first:

feynman model login anthropic
feynman model login google
feynman model login amazon-bedrock

Then switch the default model:

feynman model set anthropic/claude-opus-4-6

The model set command accepts both provider/model and provider:model formats. feynman model login google opens the API-key flow directly, while feynman model login amazon-bedrock verifies the AWS credential chain that Pi uses for Bedrock access.

Web search configuration

Research workflows use ~/.feynman/web-search.json for web-search routing. The default auto route uses API-backed providers only: Exa, then Perplexity, then Gemini API. It does not read Chromium or Chrome cookies, so it should not trigger a macOS Keychain prompt.

Example:

{
  "provider": "auto",
  "searchProvider": "auto",
  "exaApiKey": "exa_...",
  "perplexityApiKey": "pplx-...",
  "geminiApiKey": "AIza..."
}

Gemini Web browser-cookie access is disabled by default. To opt into it, set "geminiBrowser": true in web-search.json; API-backed search is recommended for /deepresearch.

Subagent model overrides

Feynman’s bundled subagents inherit the main default model unless you override them explicitly. Inside the REPL, run:

/feynman-model

This opens an interactive picker where you can either:

• change the main default model for the session environment
• assign a different model to a specific bundled subagent such as researcher, reviewer, writer, or verifier

Per-subagent overrides are persisted in the synced agent files under ~/.feynman/agent/agents/ with a model: frontmatter field. Removing that field makes the subagent inherit the main default model again.

Thinking levels

The thinkingLevel field controls how much reasoning the model does before responding. Available levels are off, minimal, low, medium, high, and xhigh. Higher levels produce more thorough analysis at the cost of latency and token usage. You can override per-session:

feynman --thinking high

Environment variables

Feynman respects the following environment variables, which take precedence over settings.json:

Variable	Description
FEYNMAN_MODEL	Override the default model
FEYNMAN_HOME	Override the config directory (default: ~/.feynman)
FEYNMAN_THINKING	Override the thinking level
ANTHROPIC_API_KEY	Anthropic API key
OPENAI_API_KEY	OpenAI API key
GEMINI_API_KEY	Google Gemini API key
AWS_PROFILE	Preferred AWS profile for Amazon Bedrock
TAVILY_API_KEY	Tavily web search API key
SERPER_API_KEY	Serper web search API key

Session storage

Each conversation is persisted as a JSON file in ~/.feynman/sessions/. To start a fresh session:

feynman --new-session

To point sessions at a different directory (useful for per-project session isolation):

feynman --session-dir ~/myproject/.feynman/sessions

Diagnostics

Run feynman doctor to verify your configuration is valid, check authentication status for all configured providers, and detect missing optional dependencies. The doctor command outputs a checklist showing what is working and what needs attention.