@shawnhamby/pi-lsp

Language Server Protocol tools and bounded inline diagnostics for the Pi coding agent. This is a focused fork of @spences10/pi-lsp that retains its secure language-server process handling and adds an OMP-style diagnostic feedback loop after file mutations.

Install

Install the Git repository directly:

pi install git:github.com/shawnhamby/pi-lsp

The repository's reviewed main branch is the release channel. Fork maintenance and pushes happen outside Pi; Pi only loads or refreshes the Git package.

For local development or a one-run smoke test:

pi -e /absolute/path/to/pi-lsp

Pi loads the checked-in TypeScript extension directly for Git installs. The compiled dist entry remains available to package consumers.

What it provides

The extension registers tools for:

• diagnostics, including batched diagnostics;
• hover information;
• definitions, implementations, and references;
• document and workspace symbols;
• preview-only symbol rename.

The tool names, descriptions, and schemas are registered immediately so Pi can offer them on the first turn. The language-server manager and inline-diagnostic runtime load once, on demand, when an LSP tool runs, /lsp opens, or an enabled write/edit diagnostic is requested. A session that never needs code intelligence does not import that runtime or start a language server.

It also watches successful Pi write operations by default. Fresh errors and warnings that arrive within 500 ms are appended to the tool result. Slower diagnostics may arrive for up to 12 seconds as a non-turn-triggering steering message. Newer edits supersede older pending diagnostics, unchanged findings are deduplicated, clean results stay silent, and watched-file notifications keep language servers current when files are created or changed.

Automatic diagnostics after edit are off by default because frequent patch operations can create noisy intermediate states. A custom harness can enable them:

import { create_lsp_extension } from '@shawnhamby/pi-lsp';

export default create_lsp_extension({
  diagnostics_on_write: true,
  diagnostics_on_edit: true,
  inline_budget_ms: 500,
  deferred_budget_ms: 12_000,
  settle_ms: 200,
});

Language servers

The fork discovers these installed servers; it never installs a server or executes a repository-controlled binary without the inherited trust check.

Languages	Server
TypeScript, JavaScript	tsc --lsp --stdio
Svelte	svelteserver
Python	pyright-langserver
Go	gopls
Rust	rust-analyzer
C, C++, Objective-C	clangd
Swift	sourcekit-lsp
Ruby	solargraph
Java	jdtls
Lua	lua-language-server

Project-local binaries in node_modules/.bin are resolved before global binaries. They are untrusted by default because repositories can control them. Interactive sessions ask before execution; headless sessions skip them unless MY_PI_LSP_PROJECT_BINARY=allow or MY_PI_LSP_PROJECT_BINARY=trust is set. Language-server child processes receive a restricted environment. Additional variables can be admitted through MY_PI_LSP_ENV_ALLOWLIST or the shared MY_PI_CHILD_ENV_ALLOWLIST.

TypeScript uses the compiler's native LSP mode. A project-local tsc remains subject to the same trust decision, and a compiler version without --lsp support fails with its unsupported-option error instead of silently starting a second server. Pyright may be project-local under that trust policy; otherwise its executable must be the verified path reported by the canonical pnpm global environment. An unrelated pyright-langserver on PATH, such as a duplicate shared-venv installation, is not used.

lsp_rename_preview calls textDocument/prepareRename before textDocument/rename, accepts only in-workspace file: text edits, and never applies them. Resource create, rename, or delete operations and out-of-workspace targets are rejected.

Commands

/lsp status
/lsp list
/lsp restart all
/lsp restart <language>

Opening /lsp is itself a lazy-load trigger. Before that first load, command completion offers the stable subcommands and restart all; language-specific restart completions appear after the manager is available.

Custom harness options

create_lsp_extension accepts callbacks for language detection, workspace-root selection, server configuration, supported-language reporting, file-path authorization, and returned-URI validation. The defaults confine tool targets to the current working directory and definition/reference results to the resolved workspace root. Normal Pi installations load the package entry directly and do not need any workspace wrapper.

The package exports CreateLspExtensionOptions, CreateLspServerManagerOptions, LspServerConfig, LspClientLike, mutation diagnostic types, and diagnostic snapshot/wait types for custom harnesses.

Development

pnpm install --ignore-scripts
pnpm run check
pnpm run test
pnpm run build

Attribution

The original implementation is Copyright Scott Spence and contributors and is used under the MIT License. See NOTICE.md for the fork baseline and attribution details. See UPSTREAM.md for the agent-managed upstream update and Git-refresh process.

License

MIT