Express

Chimpbase's route handler uses the Web standard Request/Response API. Express uses its own req/res API, so you need a thin adapter to bridge them.

Setup

npm install express @chimpbase/node

Adapter

Convert between Express and Chimpbase's Web API handler:

import express from "express";
import { createChimpbase } from "@chimpbase/node";
import { action, v } from "@chimpbase/runtime";

const app = express();
app.use(express.json());

const chimpbase = await createChimpbase({
  storage: { engine: "postgres", url: process.env.DATABASE_URL },
});

const createTodo = action({
  args: v.object({ title: v.string() }),
  async handler(ctx, input) {
    const [todo] = await ctx.db.query<{ id: number }>(
      "insert into todos (title) values (?1) returning id",
      [input.title],
    );
    return todo;
  },
});

chimpbase.register({ createTodo });

Calling actions from routes

Use chimpbase.run() to execute actions from Express route handlers:

app.post("/todos", async (req, res) => {
  try {
    const result = await chimpbase.run("createTodo", req.body);
    res.status(201).json(result);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.listen(3000, () => {
  console.log("listening on :3000");
});

await chimpbase.start();

When to use Express

If you have an existing Express application and want to add Chimpbase's background jobs, cron, and workflow capabilities without rewriting your HTTP layer, this approach lets you adopt Chimpbase incrementally.

For new projects, consider Hono instead — it uses the same Web standard API as Chimpbase with no adapter needed.