> ## Documentation Index
> Fetch the complete documentation index at: https://bun-1dd33a4e-farm-ad2450b3-transpiler-cache-version-namespa.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Configure TLS on an HTTP server

Set the `tls` key to configure TLS. Both `key` and `cert` are required: `key` is the contents of your private key and `cert` is the contents of your issued certificate. Use [`Bun.file()`](/runtime/file-io#reading-files-bun-file) to read them.

```ts server.ts icon="https://mintcdn.com/bun-1dd33a4e-farm-ad2450b3-transpiler-cache-version-namespa/pVrMBuZvntvIe2NO/icons/typescript.svg?fit=max&auto=format&n=pVrMBuZvntvIe2NO&q=85&s=81fcaf3ac2cead5d758f3588a492f46a" theme={"theme":{"light":"github-light","dark":"dracula"}}
const server = Bun.serve({
  fetch: request => new Response("Welcome to Bun!"),
  tls: {
    cert: Bun.file("cert.pem"),
    key: Bun.file("key.pem"),
  },
});
```

***

By default, Bun trusts the Mozilla-curated list of well-known root CAs. To override this list, pass an array of certificates as `ca`.

```ts server.ts icon="https://mintcdn.com/bun-1dd33a4e-farm-ad2450b3-transpiler-cache-version-namespa/pVrMBuZvntvIe2NO/icons/typescript.svg?fit=max&auto=format&n=pVrMBuZvntvIe2NO&q=85&s=81fcaf3ac2cead5d758f3588a492f46a" theme={"theme":{"light":"github-light","dark":"dracula"}}
const server = Bun.serve({
  fetch: request => new Response("Welcome to Bun!"),
  tls: {
    cert: Bun.file("cert.pem"),
    key: Bun.file("key.pem"),
    ca: [Bun.file("ca1.pem"), Bun.file("ca2.pem")],
  },
});
```