Pi vs Muse Code

Pi

Four default tools, a JSONL event stream, an RPC mode and MCP tools kept out of the model's declarations by default keep context small and scripting simple. Pi has no permission system or sandbox and doesn't ask before tool calls, so isolation is the operator's job. Version 1.0.0 is dated 1 October 2026.

Muse Code

Muse Code runs with approvals and an OS sandbox on by default, per-host network approval, an append-only event log and a headless mode with documented exit codes. It is the only route to Muse Wonder Full. It is closed source with undated release notes and no free route, and subscriptions allow training on code unless Contributor mode is turned off.

Pi

1. Run Pi inside a container or VM for unattended work. It has no sandbox and doesn't ask before running shell commands
2. Use pi --mode json and wait for agent_settled. A failed response doesn't set a nonzero exit code in JSON mode
3. Split the JSONL stream on LF only. Node's readline also splits on U+2028 and U+2029, which are valid inside JSON strings
4. Pass --no-approve or --approve in scripts to make the project trust decision explicit
5. Set PI_TELEMETRY=0 and PI_SKIP_VERSION_CHECK=1, or PI_OFFLINE=1, to stop the default requests to pi.dev

Muse Code

1. Set META_API_KEY for headless runs. Browser sign-in isn't available in CI or for Meta Managed Accounts
2. Gate on your own test command, not the exit code. muse exec returns 0 when the turn completes even if tests still fail
3. Pass --max-model-steps on unattended runs so a stuck task can't loop
4. Prefer --disable-approval to --yolo in CI so the sandbox stays on. On Linux the runner needs a working bubblewrap and a non-musl build
5. Turn Contributor mode off in /settings before a subscription session touches private code