Environments

KV namespaces can be used with environments. This is useful when you have code in your Worker that refers to a KV binding like MY_KV, and you want to have these bindings point to different KV namespaces (for example, one for staging and one for production).

The following code in the wrangler.toml file shows you how to have two environments that have two different KV namespaces but the same binding name:

wrangler.toml
[env.staging]
kv_namespaces = [
  { binding = "MY_KV", id = "e29b263ab50e42ce9b637fa8370175e8" }
]

[env.production]
kv_namespaces = [
  { binding = "MY_KV", id = "a825455ce00f4f7282403da85269f8ea" }
]

Using the same binding name for two different KV namespaces keeps your Worker code more readable.

In the staging environment, MY_KV.get("KEY") will read from the namespace ID e29b263ab50e42ce9b637fa8370175e8. In the production environment, MY_KV.get("KEY") will read from the namespace ID a825455ce00f4f7282403da85269f8ea.

To insert a value into a staging KV namespace, run:

$ wrangler kv:key put --env=staging --binding=<YOUR_BINDING> "<KEY>" "<VALUE>"

Since --namespace-id is always unique (unlike binding names), you do not need to specify an --env argument:

$ wrangler kv:key put --namespace-id=<YOUR_ID> "<KEY>" "<VALUE>"

Most kv subcommands also allow you to specify an environment with the optional --env flag.

Specifying an environment with the optional --env flag allows you to publish Workers running the same code but with different KV namespaces.

For example, you could use separate staging and production KV namespaces for KV data in your wrangler.toml file:

wrangler.toml
type = "webpack"
name = "my-worker"
account_id = "<account id here>"
route = "staging.example.com/*"
workers_dev = false

kv_namespaces = [
  { binding = "MY_KV", id = "06779da6940b431db6e566b4846d64db" }
]

[env.production]
route = "example.com/*"
kv_namespaces = [
  { binding = "MY_KV", id = "07bc1f3d1f2a4fd8a45a7e026e2681c6" }
]

With the wrangler.toml file above, you can specify --env production when you want to perform a KV action on the KV namespace MY_KV under env.production.

For example, with the wrangler.toml file above, you can get a value out of a production KV instance with:

$ wrangler kv:key get --binding "MY_KV" --env=production "<KEY>"