simple persistent cookiejar system

Get callsites from the V8 stack trace API

User-facing permission presets (ctx.permissionPresets) for the DeepSeek Harness: one product-level Permissions select bundling the sandbox-mode and approval-policy knobs, written through to their own session events

Generate icon and splash screen images for Capacitor apps

Resolve and inject Neon connection strings for the branch selected by your neon.ts policy. fetchEnv / parseEnv plus a `neon-env` CLI with `run` and `export`.

Get Windows System Root certificates

Shared Claude Code / Codex hook wire protocol: matcher engine, stdin/exit-code/stdout codec, multi-hook merge, and hook/* session events

```js import { copycat } from '@snaplet/copycat'

FLEX for JavaScript and TypeScript: the fast lexical analyser generator, emitting scanners with no dependencies

Gracefully restore the CLI cursor on exit

Framework-agnostic helpers for building A2UI subagent tools — op builders, prompt assembly, history walkers, and request/envelope orchestration shared across framework adapters.

diff with unified diff format handling

Compiler-independent Remote metadata and Typert provider protocols

tar-stream is a streaming tar parser and generator and nothing else. It operates purely using streams which means you can easily extract/parse tarballs without ever hitting the file system.

Higher-level content negotiation

Web ask_user_question feature: host tool mount plus composer-takeover question UI

Compose custom types containing mutually exclusive keys, using this generic Typescript helper type.

Wire consumer layer: HTTP-up/WebSocket-down client, ConnectionController dual streams with reconnect, and fixture api

A Plugin that uploads images to imgur

The AgentSignal plugin for Claude Code — slash commands, skills, hooks and the local dashboard.