pi vs e, in one table
Direct answer: e and pi share the same core harness, the same four tools (read, write, edit, bash), the same provider ecosystem and classical package compatibility. They differ on one axis: pi 0.99 ships MCP, codemode and tool-search as built-in extensions. e removes them entirely, along with version checking and install telemetry. Choose pi for the built-in addons; choose e to keep the original promise.
Comparison
| Capability | pi (0.99.2) | e |
|---|---|---|
| Core tools | read, write, edit, bash | read, write, edit, bash (same) |
| MCP | Built-in extension, mcp.json, /mcp, OAuth | Removed. No config can enable it. |
| Codemode | Built-in JS sandbox, opt-in tool | Removed. |
| Tool search | Built-in deferred-tool finder | Removed. |
| Sub-agents | None | None (same as upstream) |
| Plan mode | None | None (same as upstream) |
| Permission popups | None (sandbox instead) | None (same as upstream) |
| Sub-agent example extensions | Community examples available | Classical community examples work |
| Classical pi packages | Yes | Yes |
| Packages needing 0.99 built-in APIs | Yes | No, by design |
| Version check phone-home | Yes, pi.dev | Disabled |
| Install telemetry | Yes, opt-out | Removed |
| Self-update channel | pi managed install / pi update | Disabled (npm is the channel) |
| Upstream fixes | Source | Cherry-picked weekly |
| License | MIT | MIT, lineage credited |
The one decision axis
Everything in the table follows from one design stance. pi's current direction says the addons are valuable enough to carry, as long as they stay quiet. e's stance says the promise is the product, and a promise kept only by configuration is not kept. Neither stance is dishonest. They are two different products that used to be one. The table exists so you can pick yours in thirty seconds.
Migration in both directions
- pi to e: install with npm i -g @subimpact/e. Your project files, AGENTS.md files, skills and classical packages carry over. User-level config moves to ~/.e (legacy PI_* environment variables stay honored).
- e to pi: reinstall upstream pi. e adds nothing upstream needs to remove, because e only deletes. The gate is one-way: fixes flow in, addons do not.
Quick answers
Is e just pi minus features? No. The core harness is identical; the carve is exactly three addon systems plus the phone-home surfaces. Read the table.
Do pi packages work on e? Classical ones do. Packages needing the 0.99 built-in APIs do not, deliberately.
Which is lighter? Both are small; e's running surface is the leaner one because the addon code no longer exists in its binary.