Pi Coding Agent

pi-coding-agent is an Emacs front end for Pi, a coding-agent harness. The Pi CLI keeps running the agent, talking to models, and executing tools; the package talks to it over RPC and presents the session as two Emacs buffers: a Markdown chat buffer with the conversation, tool output, and thinking blocks, and a separate input buffer where you compose the next prompt.

Because the prompt lives in an ordinary buffer, you edit it with your existing Emacs habits: multi-line editing, the kill ring, keyboard macros, registers, spell checking, or Evil. Slash commands, prompt templates, skills, and file paths complete with TAB. The chat buffer renders Markdown with tree-sitter highlighting for code blocks and diffs, collapses long tool output to a preview, rewraps wide tables to the window width, and opens file targets at a line and column with RET.

Each project directory gets its own session, and named sessions allow several per directory. You can queue a follow-up while Pi is busy, send a steering message that interrupts remaining queued tools, abort a response, resume or fork earlier sessions, and compact the context when it fills. The header line shows the current model, thinking level, cost, and context usage. Requirements are Emacs 29.1 or later with tree-sitter support, Node.js 22.19 or later, and the Pi CLI 0.84.2 or later.

Features

• Two-buffer layout: a rendered chat buffer above a plain Emacs input buffer, so the prompt is never trapped in a terminal text box
• RPC integration: Emacs receives structured messages and tool events from Pi rather than parsing terminal output
• Completion: TAB completes slash commands, prompt templates from ~/.pi/agent/prompts/, skills from ~/.agents/skills/, and file paths
• Rendered output: tree-sitter highlighting for code and diffs, collapsible tool and thinking blocks, foldable turns, and display-only table rewrapping
• File navigation: RET visits a file target at point, honoring path:line:col locations; ! runs a Dired-style shell command on it
• Session control: per-project sessions, named sessions, resume, fork from a turn, compaction, and HTML export
• Steering and queueing: queue follow-ups, send steering messages mid-turn, and abort responses
• Transient menu: C-c C-p exposes model selection, thinking level, sessions, fork, compact, export, stats, skills, and custom commands
• Project trust: passes --approve by default so project-local .pi prompts, skills, and extensions load; configurable to default or no-approve
• Evil integration: optional keybindings modeled on the Evil and Magit pairing