R2
Store object bodies and metadata independently of application compute.
- Library
Runtime.Workers - npm
@cloudflare/workers-types5.20260906.1
Objects and access
Create a bucket and attach an R2Bucket binding to the Worker that needs it. R2 also exposes an S3-compatible API for other clients. Choose object keys and lifecycle rules around the files your application owns; the Worker binding is one way to access the bucket.
R2 provides strong consistency for object operations. Cached HTTP responses have their own freshness rules. Preserve content metadata and stream large bodies instead of assuming every object fits in application memory.
File Drop
On a PUT, this Worker saves the request body as a file in R2, with HTTP metadata such as Content-Type. On a GET, writeHttpMetadata copies that metadata into the response headers. Uploads count toward the free plan's 1 million Class A operations a month, and downloads toward its 10 million Class B operations. Egress from R2 is free.
open Fable.Core
module Workers = FSharp.CloudEdge.Runtime.Workers
type Env =
abstract FILES: Workers.R2Bucket
[<ExportDefault>]
let worker: Workers.ExportedHandler<Env, obj, obj, obj> =
Workers.ExportedHandler.Create(fetch = fun request env _ ->
async {
let key = Workers.Exports.URL(U2.Case1 request.url).pathname.Substring(1)
match request.``method`` with
| "PUT" ->
let! bytes = request.arrayBuffer() |> Async.AwaitPromise
let metadata = U2.Case1 request.headers
let options = Workers.R2PutOptions.Create(httpMetadata = metadata)
let! stored =
env.FILES.put(key, U5.Case2 bytes, options) |> Async.AwaitPromise
return Workers.Exports.Response.json {| key = key; size = stored.size |}
| _ ->
let! found = env.FILES.get key |> Async.AwaitPromise
match found with
| Some file ->
let headers = Workers.Exports.Headers()
file.writeHttpMetadata headers
headers.set("etag", file.httpEtag)
let init = Workers.ResponseInit.Create(headers = headers)
return Workers.Exports.Response.Create(file.body, init)
| None ->
let notFound = Workers.ResponseInit.Create(status = 404.)
return Workers.Exports.Response.Create("Not found", notFound)
}
|> Async.StartAsPromise
|> U2.Case1)
Needs an R2 bucket binding named FILES.
Help verify the binding
Useful checks include streamed uploads and downloads, missing objects, HTTP metadata, conditional requests, and multipart completion. A compiling consumer does not establish hosted behavior. Record the package version, configuration, and observed result using the verification guide.