@ephem-sh/debugger

Dev-only observability for AI agent debugging. Captures browser and server-side logs, errors, network requests, and application state from your dev server. AI agents query this data through the dbg CLI.

Preview — under active development.

Install

npm install -D @ephem-sh/debugger

Quick start (Vite + React)

// vite.config.ts
import { debuggerPlugin } from '@ephem-sh/debugger/vite'

export default defineConfig({
  plugins: [react(), debuggerPlugin()],
})

npx dbg status
npx dbg browser console
npx dbg browser network

Supported frameworks

| Framework | Adapter | |-----------|---------| | Next.js | @ephem-sh/debugger/nextjs | | React + Vite | @ephem-sh/debugger/vite | | Vue + Vite | @ephem-sh/debugger/vite | | SvelteKit | @ephem-sh/debugger/vite + /vite/sveltekit | | React Router v7 | @ephem-sh/debugger/vite + /vite/react-router | | Astro | @ephem-sh/debugger/vite + /vite/astro | | Nuxt | @ephem-sh/debugger/vite + /nitro | | Qwik | @ephem-sh/debugger/vite | | TanStack Start | @ephem-sh/debugger/vite + /vite/tanstack-start | | Waku | @ephem-sh/debugger/vite | | Angular | @ephem-sh/debugger/angular | | Express | @ephem-sh/debugger/express | | Hono | @ephem-sh/debugger/hono | | Elysia | @ephem-sh/debugger/elysia | | Fastify | @ephem-sh/debugger/fastify | | NestJS | @ephem-sh/debugger/nest | | AdonisJS | @ephem-sh/debugger/adonis | | Nitro | @ephem-sh/debugger/nitro |

CLI

dbg browser console          # browser console logs
dbg browser errors           # browser errors
dbg browser network          # fetch, xhr, websocket
dbg browser cookies          # document cookies
dbg browser storage          # localStorage + sessionStorage
dbg server console           # server console logs
dbg server errors            # server errors
dbg status                   # session info
dbg all --json               # everything as JSON

How it works

1. Server instrumentation patches console.* and starts an IPC bridge
2. Browser client (auto-injected) captures console, errors, network, cookies, storage
3. CLI queries the session over IPC and returns structured output

All data in memory (ring buffers). Zero production footprint.

Other languages

• Go — ephem-debugger-go (Gin, Echo, Chi)
• Python — ephem-debugger-py (FastAPI, Flask, Django)
• Rust — ephem-debugger-rs (Axum, Actix, Rocket, Poem)

License

MIT