# Generate Cloudflare environment type with wrangler

Used: wrangler@3.55.0

If you're using `wrangler` to build app deployed to Cloudflare, there's a handy command this tool gives you that can generate a `.d.ts` file with all your `.dev.vars` and bindings configured in `wrangler.toml`.

```sh
wrangler types --env-interface RuntimeEnv ./types/cf.d.ts
```

The `--env-interface RuntimeEnv` option will set the name of the interface created and `./types/cf.d.ts` is the file where it should be saved.

Let's say you have a `.dev.vars` like this:

```txt {% path=".dev.vars" %}
SESSION_SECRET="s3cr3t"
```

And a `wrangler.toml` like this:

```txt {% path="wrangler.toml" }
name = "app-name"

[[d1_databases]]
binding = "DB"
database_name = "YOUR DATABASE NAME"
database_id = "YOUR DATABASE ID"
```

After running the command you will get this file:

```ts {% path="types/cf.d.ts" %}
// Generated by Wrangler on <DATE>
// by running `wrangler types --env-interface RuntimeEnv ./types/cf.d.ts`

interface RuntimeEnv {
	SESSION_SECRET: string;
	DB: D1Database;
}
```

This can then be used inside your app to type what your Cloudflare Pages and Workers receive from the context.