KVStore.prototype.put

The put() method stores a value into the KV store under a key.

Note: KV stores are eventually consistent, this means that the updated contents associated with the key key may not be available to read from all edge locations immediately and some edge locations may continue returning the previous contents associated with the key.

Syntax

put(key, value, options?)

Parameters

• key : string
  • The key to store the supplied value under within the KV store.
• value : ArrayBuffer | TypedArray | DataView| ReadableStream | URLSearchParams | String | string literal
  • The value to store within the KV store.
• options : object optional
  • An insert options parameter, supporting:
  • metadata : ArrayBuffer | TypedArray | DataView optional
    • Binary metadata associated with the entry, may be up to 1000 bytes.
  • ttl : number optional
    • TTL for the entry
  • mode : 'overwrite' | 'add' | 'append' | 'prepend' optional
    • Insert mode, defaults to 'overwrite'

Return value

Returns a Promise which resolves with undefined when the provided value has been written into the KV store.

Description

Stores the supplied value into the KV store under the supplied key.

The put() method requires its this value to be a KVStore object.

If the this value does not inherit from KVStore.prototype, a TypeError is thrown.

Exceptions

• TypeError
  • If the provided key:
    • Is any of the strings "", ".", or ".."
    • Starts with the string ".well-known/acme-challenge/"
    • Contains any of the characters "#?*[]\n\r"
    • Is longer than 1024 characters

Examples

In this example we connect to an KV Store named 'files' and save an entry to the store under the key 'hello' and then read back the value and return it to the client.

/// <reference types="@fastly/js-compute" />

import { KVStore } from "fastly:kv-store";

async function app(event) {
  const files = new KVStore('files')

  await files.put('hello', 'world')

  const entry = await files.get('hello')

  return new Response(await entry.text())
}

addEventListener("fetch", (event) => event.respondWith(app(event)))