🔑 Variables and Secrets

​Bindings

Variable and secrets are bound as follows:

Using the CLICLI
Using wrangler.tomlwrangler.toml
Using the APIJavaScript API
$ miniflare --binding KEY1=value1 --binding KEY2=value2 # or -b
wrangler.toml
[vars]
KEY1 = "value1"
KEY2 = "value2"
NUMBER = 42 # Note [vars] are automatically stringified
const mf = new Miniflare({
  bindings: {
    KEY1: "value1",
    KEY2: "value2",
  },
});

​.env Files

Variables and secrets are automatically loaded from a .env file in the current directory. This is especially useful for secrets if your .env file is .gitignored. .env files look something like this:

KEY1=value1
# Woah, comments!
KEY2=value2

You can also specify the path to a custom .env file:

Using the CLICLI
Using wrangler.tomlwrangler.toml
Using the APIJavaScript API
$ miniflare --env .env.test # or -e
wrangler.toml
[miniflare]
env_path = ".env.test"
const mf = new Miniflare({
  envPath: ".env.test",
});

​Text and Data Blobs

Text and data blobs can be loaded from files. File contents will be read and bound as strings and ArrayBuffers respectively.

Using the CLICLI
Using wrangler.tomlwrangler.toml
Using the APIJavaScript API
$ miniflare --text-blob TEXT=text.txt --data-blob DATA=data.bin
wrangler.toml
[text_blobs]
TEXT = "text.txt"
[data_blobs]
DATA = "data.bin"
const mf = new Miniflare({
  textBlobBindings: { TEXT: "text.txt" },
  dataBlobBindings: { DATA: "data.bin" },
});

​Bindings Priority

Higher priority bindings override lower priority bindings with the same name. The order (from lowest to highest priority) is:

1. Variables from wrangler.toml [vars]
2. Variables from .env files
3. WASM module bindings (--wasm, [wasm_modules])
4. Text blob bindings (--text-blob, [text_blobs])
5. Data blob bindings (--data-blob, [data_blobs])
6. Custom bindings (--binding, bindings)

​Globals

You can also bind variables or arbitrary objects to the global scope, even in modules mode:

Using the CLICLI
Using wrangler.tomlwrangler.toml
Using the APIJavaScript API
$ miniflare --global KEY1=value1 --global KEY2=value2
wrangler.toml
[miniflare.globals]
KEY1 = "value1"
KEY2 = "value2"
const mf = new Miniflare({
  globals: {
    KEY1: "value1",
    KEY2: "value2",
    FUNCTION: () => { ... }
  },
});