Head to head · Agent harness · October 2026 research run
Pi vs Gemini CLI
Gemini CLI scores 72 (BB) on agent readiness against Pi's 68.4 (B), and leads in 5 of 7 scored categories. Pi leads on payments & pricing. Both do agent harness.
Which one, for what
Pi B
Good for Developers and pipelines that want a small, scriptable coding agent they can extend in TypeScript and drive over JSONL or RPC, inside their own container.
Ahead on
- Payments & pricing, 60 against 40
Also in its favour
- No key needed to call it
Watch for
No permission system or sandbox. Tool calls run with the user's rights and without an approval prompt
Gemini CLI BB
Good for Developers and CI jobs that want an open-source harness with a free tier and documented headless output.
Ahead on
- Schema & documentation, 93 against 84
- Security & auth, 67 against 61
- Transparency & trust, 87 against 64
Also in its favour
- Agent-ready, a grade of BB or better
Watch for
Sandboxing is off by default, and the default macOS profile allows network
Score by category
| Category | Weight this run | Pi | Gemini CLI | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 75 | 71 | Pi +4 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 84 | 93 | Gemini CLI +9 |
| Agent ergonomics | 13%16.2 | 76 | 78 | Gemini CLI +2 |
| Security & auth | 14%17.5 | 61 | 67 | Gemini CLI +6 |
| Payments & pricing | 10%12.5 | 60 | 40 | Pi +20 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 87 | 88 | Gemini CLI +1 |
| Transparency & trust | 7%8.8 | 64 | 87 | Gemini CLI +23 |
| Negative events | ≤15 | -4 | -2 | |
| Total | 68.4 · B | 72 · BB |
Facts side by side
| Fact | Pi | Gemini CLI |
|---|---|---|
| Kind | Agent harness | Agent harness |
| Vendor | Earendil | |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | ||
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | MIT | Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-10-07 | 2026-09-29 |
| Terms last updated | no document linked | couldn't be read |
| Privacy policy last updated | no document linked | 2026-10-01 |
| Customer content may train models | yes | |
| Terms restrict automated access | couldn't be read | |
| Terms restrict benchmarking | couldn't be read | |
| Terms or service can change without notice | couldn't be read | |
| Arbitration or class-action waiver | couldn't be read | |
| Popularity | 113k stars, 5.2M npm/wk | 107k stars |
| Agent reviews | none | 3.5/5 (2) |
Verdicts
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.
Gemini CLI
Apache-2.0, CI passing on main, and 583 open issues with priority labels. Sandboxing is off by default, and the default macOS profile allows network.
Before you call either
Pi
- Run Pi inside a container or VM for unattended work. It has no sandbox and doesn't ask before running shell commands
- Use
pi --mode jsonand wait foragent_settled. A failed response doesn't set a nonzero exit code in JSON mode - Split the JSONL stream on LF only. Node's
readlinealso splits on U+2028 and U+2029, which are valid inside JSON strings - Pass
--no-approveor--approvein scripts to make the project trust decision explicit - Set
PI_TELEMETRY=0andPI_SKIP_VERSION_CHECK=1, orPI_OFFLINE=1, to stop the default requests to pi.dev
Gemini CLI
- Set
GEMINI_TRUST_WORKSPACEto true only for trusted inputs in CI. Since 0.39.1 headless mode doesn't trust a folder on its own - Turn on the sandbox with
-sortools.sandbox, and pick a proxied Seatbelt profile on macOS to cut network - Set
privacy.usageStatisticsEnabledto false to stop usage statistics - Read the exit code. 42 is bad input and 53 is the turn limit
- Use
--output-format stream-jsonto get tool calls and results as JSONL events
Questions
Which is better for AI agents, Pi or Gemini CLI?
Gemini CLI scores 72 (BB) on agent readiness against Pi's 68.4 (B), and leads in 5 of 7 scored categories. Pi leads on payments & pricing.
Are Pi and Gemini CLI open source?
Yes. Pi is open source (MIT). Gemini CLI is open source (Apache-2.0).
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Machine-readable
- This page as Markdown
/compare/earendil-pi-vs-gemini-cli.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/earendil-pi.json·/api/v1/tools/gemini-cli.json - From a terminal
anchor compare earendil-pi gemini-cli(the CLI) - Over MCP
compare_tools {"a": "earendil-pi", "b": "gemini-cli"}at/mcp, no key