Can I vibecode Littlebird?

KINDA · weekend project

price $20/moyou'd save $240/yrbuild time a weekendcategory ✨ ai assistantsreplaced by 0 people

Public detail on this one is thin, so treat this entry as a first pass rather than a teardown. Anything in the "AI assistant that reads and drafts for you" shape is mostly a wrapper: a model API, a place to put your context, and a loop that runs on a schedule. A coding agent can rebuild that shape in an evening and you keep the API bill instead of the subscription. What you will not rebuild in an evening is the polish, the mobile surface, and whatever integrations the paid product ships against your actual accounts. Verdict stays "kinda" until someone confirms whether the real value here is the agent loop or the connectors underneath it.

the prompt

Build a local personal AI assistant web app in an empty folder. No accounts, no cloud, no telemetry.

Stack, no substitutions:
- TypeScript, Node 20, Fastify for the server
- SQLite via better-sqlite3, file at ./data/assistant.db
- Server-rendered HTML with htmx for interactivity, plain CSS, no React, no Tailwind
- OpenAI-compatible chat completions and embeddings, base URL and key read from .env (OPENAI_API_KEY, OPENAI_BASE_URL, CHAT_MODEL, EMBED_MODEL)
- node-cron for scheduled jobs, all in one process

Features in scope:
1. Context library: paste text, upload .md/.txt, or submit a URL. URLs are fetched server side and reduced to readable text with @mozilla/readability plus jsdom. Chunk to ~800 tokens, embed, store chunks and vectors in SQLite.
2. Chat: a single conversation view. On each message, retrieve the top 8 chunks by cosine similarity, put them in the system prompt with source titles, stream the reply back. Persist all turns.
3. Watchlist: each row is a name, a URL or a search query, and a cadence (daily or weekly). A cron job fetches each item, diffs the extracted text against the last stored snapshot, and asks the model to summarize what changed in under 80 words. Skip items with no meaningful diff.
4. Digest: a /digest page listing the latest summaries newest first, plus a digest.md file written to ./out/ after each run so it is greppable.
5. Every model call is logged to a calls table with model, token counts and latency, and /usage shows totals by day so you can see what you are spending.

Out of scope, do not build: user accounts, OAuth to any third party, email or push notifications, mobile app, multi-user sharing, vector database services, Docker.

Deliver: npm install, npm run dev on port 3000, a seeded example watchlist item, .env.example with every variable, and a README that states plainly what works and what breaks if the process dies.

$ open in your agent (prompt prefilled, you press enter) or copy it raw · this prompt is generated from the build plan · improve it via PR

why people still pay

Because assembling the loop is the easy 20 percent and living with it is the other 80. A paid assistant already has the auth flows, the retry logic, the mobile push, and a prompt someone iterated on for months against real complaints. A self-hosted clone works great for two weeks and then you stop opening the tab, which is the actual failure mode of every personal AI build.

what you lose

xMobile app and notifications; your version is a browser tab

xPrebuilt connectors to email, calendar, Slack and whatever else the paid product authenticates against

xSomeone else tuning prompts and swapping models when a better one ships

xReliability: your cron job dies silently and nobody pages you

xAny team or sharing features, if the product has them

prior art · use these instead of building, if you'd rather

Nothing worth pointing at. That's why the prompt exists.

share on X ↗"I just replaced Littlebird ($20/mo) with one prompt"