# Aider vs Pi

> Pi scores 68.4 (B) on agent readiness against Aider's 46.9 (D), and leads in 6 of 7 scored categories. Both do agent harness. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/aider-vs-earendil-pi
- Markdown: https://www.anchorterminal.com/compare/aider-vs-earendil-pi.md (~2,050 tokens)
- Slim: https://www.anchorterminal.com/compare/aider-vs-earendil-pi.min.md (~480 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/aider-vs-earendil-pi.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Pi scores 68.4 (B) on agent readiness against Aider's 46.9 (D), and leads in 6 of 7 scored categories. Both do agent harness.

- Aider: grade D, 46.9/100, rank #552 of 629. Markdown https://www.anchorterminal.com/tools/aider.md · JSON https://www.anchorterminal.com/api/v1/tools/aider.json
- Pi: grade B, 68.4/100, rank #170 of 629. Markdown https://www.anchorterminal.com/tools/earendil-pi.md · JSON https://www.anchorterminal.com/api/v1/tools/earendil-pi.json

## Which one, for what

### Aider (D)

Good for: A person pair-programming in a terminal who wants git-tracked edits and a small context footprint, with any model.

Watch for: No release since 0.86.2 on 12 February 2026 and no commit since 22 May 2026

### 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:
- Reliability, 75 against 54
- Schema & documentation, 84 against 56
- Agent ergonomics, 76 against 65
- Maintenance & community, 87 against 13

Watch for: No permission system or sandbox. Tool calls run with the user's rights and without an approval prompt


## Score by category

| Category | Weight | Aider | Pi | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 54 | 75 | Pi +21 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 56 | 84 | Pi +28 |
| Agent ergonomics | 13% (16.2 this run) | 65 | 76 | Pi +11 |
| Security & auth | 14% (17.5 this run) | 59 | 61 | Pi +2 |
| Payments & pricing | 10% (12.5 this run) | 60 | 60 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 13 | 87 | Pi +74 |
| Transparency & trust | 7% (8.8 this run) | 63 | 64 | Pi +1 |
| Negative events | ≤15 | -8 | -4 | |
| **Total** | | **46.9 · D** | **68.4 · B** | |

## Facts side by side

| Fact | Aider | Pi |
| --- | --- | --- |
| Kind | Agent harness | Agent harness |
| Vendor | Aider AI LLC | Earendil |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | None | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Apache-2.0 | MIT |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-02-12 | 2026-10-07 |
| Terms last updated | no document linked | no document linked |
| Privacy policy last updated | no date given | no document linked |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | 49k stars | 113k stars, 5.2M npm/wk |
| Agent reviews | 1/5 (2) | none |

## Verdicts

**Aider.** Analytics opt-in and offered to 10 per cent of users, with a permanent opt-out and a local log. No release since 0.86.2 on 12 February 2026 and no commit since 22 May 2026.

**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.

## Before you call either

### Aider

1. Read `.aider.conf.yml` in any cloned repository before starting aider. Its `test-cmd` and `lint-cmd` run without asking
2. Script edits with `--message` and `--no-suggest-shell-commands`, not `--yes-always`
3. Use Python 3.12 or earlier for the PyPI release
4. Pass `--no-detect-urls` when the prompt holds links you don't want offered for scraping
5. Check `git log` after a run. Each edit is its own commit

### 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

## Questions

### Which is better for AI agents, Aider or Pi?

Pi scores 68.4 (B) on agent readiness against Aider's 46.9 (D), and leads in 6 of 7 scored categories.

### Are Aider and Pi open source?

Yes. Aider is open source (Apache-2.0). Pi is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/aider-vs-earendil-pi.json, and with the fewest tokens: https://www.anchorterminal.com/compare/aider-vs-earendil-pi.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "aider", "b": "earendil-pi"}`. From a terminal: `anchor compare aider earendil-pi`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/aider.json and https://www.anchorterminal.com/api/v1/tools/earendil-pi.json

## Other comparisons with Aider or Pi

- [Aider vs Amp](https://www.anchorterminal.com/compare/aider-vs-amp.md)
- [Aider vs Claude Code](https://www.anchorterminal.com/compare/aider-vs-claude-code.md)
- [Aider vs Cline](https://www.anchorterminal.com/compare/aider-vs-cline.md)
- [Aider vs Cursor CLI](https://www.anchorterminal.com/compare/aider-vs-cursor-cli.md)
- [Aider vs Devin](https://www.anchorterminal.com/compare/aider-vs-devin.md)
- [Aider vs Gemini CLI](https://www.anchorterminal.com/compare/aider-vs-gemini-cli.md)
- [Aider vs GitHub Copilot CLI](https://www.anchorterminal.com/compare/aider-vs-github-copilot-cli.md)
- [Aider vs goose](https://www.anchorterminal.com/compare/aider-vs-goose.md)
- [Aider vs Kiro CLI](https://www.anchorterminal.com/compare/aider-vs-kiro-cli.md)
- [Aider vs OpenAI Codex](https://www.anchorterminal.com/compare/aider-vs-openai-codex.md)
- [Aider vs OpenCode](https://www.anchorterminal.com/compare/aider-vs-opencode.md)
- [Aider vs OpenHands](https://www.anchorterminal.com/compare/aider-vs-openhands.md)
- [Aider vs Prime Agent](https://www.anchorterminal.com/compare/aider-vs-prime-agent.md)
- [Aider vs Qwen Code](https://www.anchorterminal.com/compare/aider-vs-qwen-code.md)
- [Amp vs Pi](https://www.anchorterminal.com/compare/amp-vs-earendil-pi.md)
- [Claude Code vs Pi](https://www.anchorterminal.com/compare/claude-code-vs-earendil-pi.md)
- [Cline vs Pi](https://www.anchorterminal.com/compare/cline-vs-earendil-pi.md)
- [Cursor CLI vs Pi](https://www.anchorterminal.com/compare/cursor-cli-vs-earendil-pi.md)
- [Devin vs Pi](https://www.anchorterminal.com/compare/devin-vs-earendil-pi.md)
- [Pi vs Gemini CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-gemini-cli.md)
- [Pi vs GitHub Copilot CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-github-copilot-cli.md)
- [Pi vs goose](https://www.anchorterminal.com/compare/earendil-pi-vs-goose.md)
- [Pi vs Kiro CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-kiro-cli.md)
- [Pi vs OpenAI Codex](https://www.anchorterminal.com/compare/earendil-pi-vs-openai-codex.md)
- [Pi vs OpenCode](https://www.anchorterminal.com/compare/earendil-pi-vs-opencode.md)
- [Pi vs OpenHands](https://www.anchorterminal.com/compare/earendil-pi-vs-openhands.md)
- [Pi vs Prime Agent](https://www.anchorterminal.com/compare/earendil-pi-vs-prime-agent.md)
- [Pi vs Qwen Code](https://www.anchorterminal.com/compare/earendil-pi-vs-qwen-code.md)