DenoHttpClient unstable

When to use

Use when you need the native client itself, for example to call fetch directly with { client } or to share one client between several layers, with the same scoped cleanup layerOptions provides. Otherwise prefer layerOptions.

declare function makeClient(options?: any): Effect<HttpClient, never, Scope>

When to use

Use when an Effect program should execute HttpClient requests through the platform fetch implementation, especially in browser, edge, or Node.js runtimes with globalThis.fetch.

Details

The layer uses the current Fetch reference and optional RequestInit service for each request. Request-specific method, headers, body, and abort signal are supplied by the client and override matching RequestInit fields.

Gotchas

Fetch behavior comes from the runtime's implementation, so CORS, cookies, redirects, abort handling, and streaming support can vary by platform. fetch follows redirects itself by default, so HttpClient.followRedirects has no effect unless RequestInit sets redirect: "manual". Trace propagation is on by default, and a browser preflight fails unless the target allows b3 and traceparent. Stream request bodies are sent as Web streams with duplex: "half" when the runtime supports it; see StreamBodyFallback for the unsupported case. Any content-length header is removed before calling fetch. Chrome passes the support check but rejects streaming uploads over HTTP/1.1, which surfaces as a TransportError, and browsers only deliver the response after the entire request body has been sent.

See

• Fetch for supplying the fetch implementation used by this layer
• RequestInit for default RequestInit options applied before request-specific fields
• StreamBodyFallback for opting into buffering on unsupported runtimes
• HttpClient.TracerPropagationEnabled for leaving b3 and traceparent off a browser request

declare const layer: Layer.Layer<HttpClient.HttpClient>

When to use

Use to send every request over a Unix domain socket with { proxy: { transport: "unix", path } }, or over TLS with a custom CA and client certificate with { caCerts: [ca], cert, key }.

Details

The native client is acquired in the layer's scope and closed when the scope ends. Before each request it is set as the client field of the RequestInit in effect for that request: the RequestInit service in the request context, or otherwise the one provided while building this layer. An application-wide RequestInit for credentials, cache or default headers therefore still applies, and only client is overridden. Method, headers, body and abort signal are set per request.

See

• Options for the accepted fields and limitations
• makeClient for acquiring the native client on its own

declare function layerOptions(options?: any): Layer<HttpClient>

import { DenoHttpClient } from "@effect/platform-deno"

const DockerClient = DenoHttpClient.layerOptions({
  proxy: { transport: "unix", path: "/var/run/docker.sock" }
})

import { DenoHttpClient } from "@effect/platform-deno"

declare const ca: string
declare const cert: string
declare const key: string

const MtlsClient = DenoHttpClient.layerOptions({ caCerts: [ca], cert, key })

Details

Supported fields include caCerts for additional root certificates, cert and key for a client certificate in PEM format, proxy for an alternative transport (http, https, socks5, tcp, unix or vsock), poolMaxIdlePerHost, poolIdleTimeout, http1, http2, allowHost and localAddress.

Deno has no option to skip certificate verification or to override the server name used for verification. Unix domain socket transports are not supported on Windows.

type Options = Parameters<typeof Deno.createHttpClient>[0]

Details

Defaults to globalThis.fetch.

declare const Fetch: Context.Reference<typeof globalThis.fetch>

When to use

Use to provide default credentials, cache, redirect, integrity, or other fetch options for outgoing HTTP requests.

Details

Request-specific method, headers, body, and abort signal are supplied by the client when a request is executed.

See

• HttpClient.followRedirects for following redirects in the client, which needs { redirect: "manual" } here

declare class RequestInit extends RequestInit_base {
  constructor(_: never);
}

Details

Defaults to "error", which fails with an EncodeError without sending the request. Set to "buffer" to collect the entire stream in memory and send it as a single body instead. Runtimes with streaming support always send the stream.

Gotchas

Buffering keeps the entire upload in memory and can exhaust memory for large or unbounded uploads. Support is detected once, on the first stream body sent, using the global Request implementation even when a custom Fetch is provided.

declare const StreamBodyFallback: Context.Reference<"buffer" | "error">