Starts the agent process.

Options

• :api_key - API key for the LLM provider
• :model - Override the default model (format: "provider:model")
• :base_url - Override the provider's default base URL
• :system_prompt - System prompt for the agent
• :load_project_instructions - Auto-load AGENTS.md, CLAUDE.md, and local skills from the project root (default: true)
• :thinking_level - Override the thinking level
• :cwd - Project working directory used for AGENTS.md/CLAUDE.md discovery and disk session storage (default: File.cwd!()). Note: tools no longer key off this value directly — they use the active sandbox.
• :sandbox - Sandbox spec for tool I/O (module, {module, opts}, or Condukt.Sandbox struct). Defaults to {Condukt.Sandbox.Local, cwd: <:cwd>}.
• :subagents - Override the agent's subagents/0 registrations. Each role can point at an agent module, {agent_module, opts}, or a keyword list of session options for an anonymous child agent.
• :secrets - Session secret declarations. Resolved at session start and exposed to command tools as environment variables without adding plaintext values to model context or snapshots.
• :session_store - Session store module or {module, opts} tuple
• :compactor - Compactor module or {module, opts} tuple (see Condukt.Compactor)
• :name - GenServer registration name

Plus all standard GenServer options.