golem-make-http-request-moonbit

Import golemcloud/golem_sdk/http and the wasi/http/types package, build an OutgoingRequest with @types.OutgoingRequest::outgoing_request(headers), finish the body, then send it with @http.handle and block on the future's pollable to get the response.

Set the method with request.set_method(@types.Post), add a Content-Type header via Fields::from_list, write the JSON string through the body's output stream, drop the stream, finish the body, then call @http.handle. Field values must be FixedArray[Byte] encoded with @utf8.encode.

WASI field-value types are FixedArray[Byte], not Bytes, so b"..." literals do not type-check with Fields::append or from_list. Convert strings using @utf8.encode(s).to_fixedarray(), and never use String::to_bytes() which returns UTF-16LE.

Yes, Golem automatically records outgoing HTTP requests and responses in the agent's oplog, so on replay the recorded response is returned instead of re-executing the network call. No manual durability wrapping is needed.

Define a named retry policy in golem.yaml whose predicate matches the status-code property for values like 500, 502, 503, and 504, with an exponential backoff policy. The host transparently re-sends the request, and POST requests work out of the box since idempotence mode defaults to true.

WASI HTTP resources have strict drop ordering: the OutputStream must be dropped before finishing the OutgoingBody, and the InputStream must be dropped before finishing the IncomingBody. Dropping resources out of order or failing to finish bodies causes a trap.