effect-http-client

Provide a transport layer such as FetchHttpClient.layer or NodeHttpClient.layerUndici, then access the HttpClient.HttpClient service and call methods like client.get or client.post. Responses expose effectful body getters like response.json and response.text.

Use HttpClient.retryTransient, which retries transient statuses (408, 429, 500, 502, 503, 504), TransportError, and TimeoutError with an optional Schedule and times cap. For custom logic, HttpClient.retry accepts the same options as Effect.retry.

No. In v4 the HTTP client lives in the effect package under effect/unstable/http. Only platform transports like NodeHttpClient and BunHttpClient remain in @effect/platform-node and @effect/platform-bun.

Pass your schema to HttpClientResponse.schemaBodyJson and flatMap it over the request effect. Decoding failures surface as SchemaError, and you can also use matchStatus to handle different status codes with different decoders.

Build a mock with HttpClient.make, returning HttpClientResponse.fromWeb(request, new Response(...)), then provide it via Layer.succeed(HttpClient.HttpClient, mockClient). You can route by request to simulate failures and count retry attempts.

By default any status is a success. Apply HttpClient.filterStatusOk at the client level to turn non-2xx responses into StatusCodeError failures, or use HttpClientResponse.filterStatusOk for a single request.