picc-write

Claude Code style Write tool for pi — a faithful port of Claude Code's Write tool, overriding pi's built-in write.

Part of picc, a pi agent setup mirroring Claude Code's harness.

pi's built-in write is a thin fs.writeFile wrapper: input path (relative or absolute), no "must read first" guard, no create/update distinction, and a Successfully wrote N bytes message. This extension replicates Claude Code's Write: file_path (absolute) input, a session-scoped read-first guard, create-vs-update results with a structured diff, and faithful success messages.

Usage

Install via pi install npm:@ladbabynpm/picc-write.

Tool

• Name: write (default; overrides pi's built-in write) or Write — configurable (see below).
• Parameters: file_path (absolute, required), content (required).
• Behavior:
  • New file — parent dirs are created automatically; returns File created successfully at: <path>.
  • Existing file — must have been read this session (any read tool), and must not have been modified since that read; returns The file <path> has been updated successfully. with a structured diff.
  • Writes with explicit LF handling (the model's sent line endings are respected as-is — no repo resampling).
• Read-first guard: reads are observed from pi tool_result events for any read tool (read/Read), so it works whether the file was read with pi's built-in read or picc-read's Read. The map is cleared on session_start.

Configuration

| Setting | Where | Values | Default | |---|---|---|---| | toolName | config.json | "write" | "Write" | "write" | | PICC_WRITE_TOOL_NAME | env | "write" | "Write" | — | | PICC_WRITE_CONFIG_PATH | env | absolute path to a config.json | ~/.pi/agent/extensions/picc-write/config.json |

Precedence for the tool name: PICC_WRITE_TOOL_NAME env > config.json > "write".

What is omitted from the live source

No pi equivalent, so left out: permission checks (checkWritePermissionForTool), checkTeamMemSecrets, team-memory guards, skill discovery, fileHistory, LSP didChange/didSave, notifyVscodeFileUpdated, gitDiff, and analytics.

Development

npm install
npm run lint        # biome check
npm run typecheck   # tsc --noEmit
npm run test        # vitest run