KV bindings
KV bindings allow for communication between a Worker and a KV namespace.
Configure KV bindings in the wrangler.toml file.
A KV namespace is a key-value database replicated to Cloudflare’s global network.
To connect to a KV namespace from within a Worker, you must define a binding that points to the namespace’s ID.
The name of your binding does not need to match the KV namespace’s name. Instead, the binding should be a valid JavaScript identifier, because the identifier will exist as a global variable within your Worker.
A KV namespace will have a name you choose (for example, My tasks
), and an assigned ID (for example, 06779da6940b431db6e566b4846d64db
).
To execute your Worker, define the binding.
In the following example, the binding is called TODO
. In the kv_namespaces
portion of your wrangler.toml
file, add:
With this, the deployed Worker will have a TODO
field in their environment object (the second parameter of the fetch()
request handler). Any methods on the TODO
binding will map to the KV namespace with an ID of 06779da6940b431db6e566b4846d64db
– which you called My Tasks
earlier.
Durable Objects use ES modules format. Instead of a global variable, bindings are available as properties of the env
parameter passed to the constructor.
An example might look like: