Add E-Signatures to Hono

Quick start

1. Get an API key from signb.ee (free, no credit card)
2. Set SIGNBEE_API_KEY in your environment
3. Add the code below to your app

Hono example

import { Hono } from "hono";

const app = new Hono();

app.post("/send-contract", async (c) => {
  const body = await c.req.json();
  const res = await fetch("https://signb.ee/api/send", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${c.env.SIGNBEE_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify(body),
  });
  return c.json(await res.json());
});

export default app;

What happens

1. Your app sends markdown or a PDF URL to Signbee
2. Signbee generates a PDF (if markdown) and emails the recipient a signing link
3. Recipient signs — both parties receive the signed PDF with SHA-256 certificate

Also works with AI agents

Install the MCP server to let Claude, Cursor, or Windsurf send documents directly:

npx -y signbee-mcp

Integration details

Hono is an ultrafast, lightweight web framework that runs on any JavaScript runtime — Cloudflare Workers, Deno, Bun, Node.js, and more. Adding e-signatures to Hono gives you a portable signing service that deploys everywhere.

Multi-runtime portability: Hono's key advantage is runtime portability. Write your signing service once and deploy to Cloudflare Workers (edge), Deno Deploy (edge), Bun (server), or Node.js (traditional). The API call is identical across all runtimes.

Cloudflare Workers: On Cloudflare Workers, access environment variables via c.env.SIGNBEE_API_KEY (as shown). Set the key in your wrangler.toml or Cloudflare dashboard. Your signing service runs in 300+ global edge locations.

Middleware: Hono has a rich middleware ecosystem. Add bearer authentication, rate limiting, CORS, and request logging as middleware. Hono's middleware is compatible across all supported runtimes.

Type-safe routes: Use Hono's RPC mode for end-to-end type-safe API calls between your client and server. Define your contract-sending route with typed request/response schemas and get compile-time type checking.

Bundle size: Hono's core is under 20KB. Combined with tree-shaking, your signing service deploys with minimal overhead — important for Cloudflare Workers where bundle size affects cold start times.

FAQs