WASI HTTP Implementation Status

Tracks whether each wasi:http feature is implemented and working, verified by passing e2e tests.

• [x] = implemented and verified (all Option/Result variants pass)
• [ ] = not yet working (bug, timeout, or missing implementation)

Items without e2e test coverage are listed in Untested Features.

Effects

Handler

• [x] async fn handle(request: Request) -> Result<Response, ErrorCode> — Ok and Err both verified (http-200, http-error-code)

Client

• [x] async fn send(request: Request) -> Result<Response, ErrorCode> — Ok verified (http-client-send-simple, http-client-send-proxy, http-client-advanced)

Resources

Fields

• [x] fn new() -> Fields (http-fields, http-200)
• [x] fn from_list(entries) -> Result<Fields, HeaderError> — Ok and Err(InvalidSyntax) verified (http-fields-from-list, http-fields-from-list-error)
• [x] fn get(name) -> List<FieldValue> — existing and non-existing names (http-fields-set, http-client-advanced)
• [x] fn has(name) -> bool — true and false (http-fields, http-request-headers, http-echo-headers)
• [x] fn set(name, value) -> Result<(), HeaderError> — Ok and Err(immutable) verified (http-fields-set, http-fields-immutable-errors)
• [x] fn delete(name) -> Result<(), HeaderError> — Ok and Err(immutable) verified (http-fields, http-fields-immutable-errors)
• [x] fn get_and_delete(name) -> Result<List<FieldValue>, HeaderError> — Ok and Err(immutable) verified (http-fields-get-and-delete, http-fields-immutable-errors)
• [x] fn append(name, value) -> Result<(), HeaderError> — Ok and Err(immutable) verified (http-fields, http-echo-headers, http-fields-immutable-errors)
• [x] fn copy_all() -> List<[FieldName, FieldValue]> (http-fields-copy-all, http-fields-immutable-errors)
• [x] fn clone() -> Fields (http-fields, http-fields-immutable-errors)

Request

• [ ] fn new(headers, contents, trailers, options) — contents=Some(Stream) times out at O0/O2; other combinations work (http-client-request-full, http-client-send-with-body)
• [x] fn get_method() -> Method (http-request-method, http-method-routing, http-method-and-scheme-variants)
• [x] fn set_method(method) -> Result<(), ()> — Ok verified; Err not triggerable (wasmtime accepts all methods) (http-client-request-full, http-request-setter-errors)
• [x] fn get_path_with_query() -> Option<String> — Some and None verified (http-request-path, http-routing, http-client-request-full)
• [x] fn set_path_with_query(path) -> Result<(), ()> — Ok(Some) and Ok(None) verified; Err not triggerable (http-client-request-full, http-request-setter-errors)
• [x] fn get_scheme() -> Option<Scheme> — Some and None verified (http-request-scheme, http-method-and-scheme-variants, http-client-request-full)
• [x] fn set_scheme(scheme) -> Result<(), ()> — Ok(Some) and Ok(None) verified; Err not triggerable (http-client-request-full, http-request-setter-errors)
• [x] fn get_authority() -> Option<String> — Some and None verified (http-request-authority, http-client-request-full)
• [x] fn set_authority(authority) -> Result<(), ()> — Ok(Some) and Ok(None) verified; Err not triggerable (http-client-request-full, http-request-setter-errors)
• [x] fn get_options() -> Option<RequestOptions> — Some and None verified (http-client-request-full, http-request-options)
• [x] fn get_headers() -> Headers (http-request-headers, http-echo-headers, http-fields-immutable-errors)
• [x] fn consume_body(this, res) -> [Stream<u8>, Future<...>] (http-client-send-body-read, http-client-advanced)

RequestOptions

• [x] fn new() -> RequestOptions (http-request-options, http-request-options-timeouts)
• [x] fn get_connect_timeout() -> Option<Duration> — Some and None verified (http-request-options-timeouts, http-client-request-full)
• [x] fn set_connect_timeout(duration) -> Result<(), RequestOptionsError> — Ok(Some), Ok(None), Err(Immutable) verified (http-request-options-timeouts, http-client-request-full)
• [x] fn get_first_byte_timeout() -> Option<Duration> — Some and None verified (http-request-options-timeouts)
• [x] fn set_first_byte_timeout(duration) -> Result<(), RequestOptionsError> — Ok verified; Err covered via Immutable path (http-request-options-timeouts)
• [x] fn get_between_bytes_timeout() -> Option<Duration> — Some and None verified (http-request-options-timeouts)
• [x] fn set_between_bytes_timeout(duration) -> Result<(), RequestOptionsError> — Ok verified; Err covered via Immutable path (http-request-options-timeouts)
• [x] fn clone() -> RequestOptions (http-request-options-timeouts)

Response

• [x] fn new(headers, contents, trailers) — contents=None and contents=Some(Stream) both verified (http-200, http-body-contains, http-response-trailers)
• [x] fn get_status_code() -> StatusCode (http-response-ops, http-client-advanced, http-response-set-status-invalid)
• [x] fn set_status_code(status_code) -> Result<(), ()> — Ok and Err (invalid codes 0, 65535) verified (http-400, http-500, http-response-set-status-invalid)
• [x] fn get_headers() -> Headers (http-response-get-headers, http-client-advanced)
• [x] fn consume_body(this, res) -> [Stream<u8>, Future<...>] (http-client-send-body-read, http-client-advanced)

Variants

Method

• [x] Get, Head, Post, Put, Delete, Connect, Options, Trace, Patch, Other(String) (http-method-routing, http-method-and-scheme-variants, http-request-method-*)

Scheme

• [x] Http, Https, Other(String) (http-method-and-scheme-variants, http-request-scheme)

ErrorCode

• [x] All 40 variants — construction, matching, and Err return from handler verified (http-error-code-comprehensive, http-error-code, http-error-code-variants, http-error-code-payload)

HeaderError

• [x] All 5 variants constructed (http-error-code-comprehensive)
• [x] Returned as Err from immutable Fields operations (http-fields-immutable-errors)
• [ ] Variant matching (e matches { Immutable }) — panics at O0/O2; Err(_) works (http-fields-immutable-errors)

RequestOptionsError

• [x] All 3 variants constructed (http-error-code-comprehensive)
• [x] Returned as Err from immutable RequestOptions set operations (http-client-request-full)

Structs

• [x] DnsErrorPayload — both Some/None fields (http-error-code-comprehensive)
• [x] TlsAlertReceivedPayload — both Some/None fields (http-error-code-comprehensive)
• [x] FieldSizePayload — both Some/None fields (http-error-code-comprehensive)

Type Aliases

• [x] FieldName, FieldValue, Headers, Trailers, StatusCode (http-fields-from-list, http-response-set-status-invalid, http-response-trailers)

Patterns

Server

• [x] Minimal response, status codes, path routing, method routing (http-200, http-400, http-500, http-routing, http-method-routing)
• [x] Header echo, error code return (http-echo-headers, http-error-code)
• [x] Stream body write (single/multi chunk, string conversion) (http-body-contains, http-response-trailers)
• [x] Request body read, echo handler (http-client-send-body-read)
• [x] Response with actual trailers (http-response-trailers)

Client

• [x] Simple send + forward, read upstream body, reverse proxy (http-client-send-simple, http-client-send-proxy, http-client-send-body-read)
• [x] Multiple sequential requests, response header reading (http-client-advanced)
• [x] Send with RequestOptions (http-client-request-full)
• [ ] Send with request body stream — times out at O0/O2 (http-client-send-with-body)

Worlds

• [x] wasi:http/service (http-200, http-routing, etc.)
• [ ] wasi:http/middleware — compiler panics when Handler effect is used in service world (http-middleware-forward)

Untested Features

These features have no e2e test due to test infrastructure limitations:

• Client::send Err(ErrorCode) variant — mock system traps on unmatched paths instead of returning ErrorCode (http-client-send-error documents this with trapped: true)
• Request.set_method Err variant — wasmtime accepts all method values including empty strings
• Request.set_path_with_query / set_scheme / set_authority Err variants — wasmtime accepts all values tested

Known Bugs

• [ ] Request.new with contents=Some(Stream<u8>) for outgoing requests times out at O0/O2 (http-client-send-with-body)
• [ ] HeaderError variant matching (e matches { Immutable }) panics at O0/O2; workaround: use Err(_) (http-fields-immutable-errors)
• [ ] Handler effect in service world causes compiler panic instead of proper error (http-middleware-forward)