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Environment Variables

| Variable | Description | |---|---|---| | PORT | Server port. Defaults to 4096. | | OPENAI_API_KEY | Enables the codex provider. | | ANTHROPIC_API_KEY | Enables the claude provider. | Providers can be listed even when they are not configured. A request fails if it targets a provider without the matching API key. When 0x0 server starts in an interactive terminal and neither provider key is present, it asks for OPENAI_API_KEY and ANTHROPIC_API_KEY. Values entered at the prompt are used only for that server process. Add exports to your shell config for durable setup: 
export OPENAI_API_KEY=...
export ANTHROPIC_API_KEY=...

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Server URL

The server binds through Bun and prints its local URL on boot: 
PORT=4107 bun run --cwd apps/server dev

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State

Agent sessions use local git worktrees and refs. The default state root is: 
~/.local/state/0x0/
Each session stores:
  • A detached agent worktree
  • A baseline ref
  • An agent-head ref
  • A sessions.json registry
Clients should treat this directory as server-owned state.