feat: proxy media uploads through native delegate for processing by dcalhoun · Pull Request #357 · wordpress-mobile/GutenbergKit

dcalhoun · 2026-03-09T12:44:15Z

What?

Adds a native media upload pipeline that routes file uploads through a local HTTP server on iOS and Android, enabling the host app to process files (e.g., resize images, transcode video) before they are uploaded to WordPress.

Why?

Ref CMM-1249.

Gutenberg's built-in upload path sends files directly from the WebView to the WordPress REST API with no opportunity for native processing. Host apps need to resize images, enforce upload size limits, or apply other transformations before upload. This pipeline gives the native layer full control over media processing while keeping the existing Gutenberg upload UX (blob previews, save locking, entity caching) unchanged.

How?

Architecture: A localhost HTTP server runs on each platform, built on the GutenbergKitHTTP library (iOS) and HttpServer (Android) from #367. The library handles TCP binding, HTTP/1.1 parsing, bearer token authentication (Relay-Authorization), multipart form-data parsing, connection limits, and disk-backed body buffering. The upload server is a thin handler on top.

JS layer:

nativeMediaUploadMiddleware in api-fetch.js intercepts POST /wp/v2/media requests when nativeUploadPort is configured in window.GBKit, forwarding the original request body (the file plus every sibling field — post, additionalData) and query string (e.g. ?_embed) to the local server. The native server relays WordPress's response verbatim: on success the middleware returns WordPress's attachment object unchanged (preserving media_details.sizes, _embedded, distinct raw/rendered fields, etc.), so the existing Gutenberg upload pipeline works unchanged
On a non-2xx it mirrors @wordpress/api-fetch and rejects with the parsed WordPress error body ({ code, message, data }) so @wordpress/media-utils surfaces WordPress's real message and code, falling back to an invalid_json error on a non-JSON body
Uses exact endpoint matching (/wp/v2/media but not /wp/v2/media/123 or /wp/v2/media-categories) to avoid intercepting non-upload requests

Native layer:

MediaUploadDelegate protocol/interface with processFile (resize/transcode) and optional uploadFile for a custom upload, which returns the raw WordPress response (MediaUploadResponse?); returning nil falls back to the default uploader
DefaultMediaUploader as fallback, uploading to /wp/v2/media via the host's HTTP client, with site API namespace support for namespaced sites. It returns WordPress's raw bytes and status without throwing on non-2xx, so the server can relay the exact response
Upload server starts whenever a delegate can handle uploads — no resources wasted otherwise. The default uploader is built only when a site API root and auth header are present; a cookie-auth host (empty auth header) with a delegate implementing uploadFile still starts the server
Server-generated errors (413, delegate/parse failures, "no uploader configured") emit a { code, message } JSON body with CORS headers so they normalize like a relayed WordPress error; oversized bodies are drained before the 413 so the WebView receives a clean response rather than a connection reset
Filename sanitization prevents path traversal from malicious Content-Disposition values

Demo apps:

Both iOS and Android demo apps include a delegate that resizes images to 2000px max
"Enable Native Media Upload" toggle (defaults to true) controls whether the delegate is set

Reliability & lifecycle:

A transport-layer failure reaching the loopback server does not fall back to a direct re-upload: retrying a non-idempotent POST /wp/v2/media could duplicate an attachment the server had already relayed. Reachability is gated proactively upstream instead (the middleware skips the native path when no port is advertised, and the native side only advertises a reachable port). A caller-initiated cancellation propagates as the cancellation (detected via signal.aborted) rather than being retried
iOS stops the upload server on deinit (not viewDidDisappear, which also fires when another view controller is presented over the editor) and holds the delegate weakly
Android re-advertises the server port and token into window.GBKit after a restart (e.g. a Compose host constructing a new delegate per recomposition) and uses a 60s upload timeout to match EditorHTTPClient, since WordPress generates image sub-sizes synchronously inside POST /wp/v2/media

Key design decisions

Localhost HTTP server over platform-specific bridges: Provides a uniform interception point for all upload paths (file picker, paste, drag-and-drop, programmatic) without requiring per-path bridge wiring. Builds on the cross-platform HTTP library from feat: add cross-platform HTTP/1.1 parser and local proxy server for iOS and Android #367 rather than hand-rolling TCP/HTTP/multipart handling
Delegate is opt-in: The server doesn't start and no configuration is injected unless the host provides a MediaUploadDelegate that can handle uploads, keeping the default behavior unchanged
api-fetch middleware over mediaUpload editor setting: Ideally, media uploads would be handled via the mediaUpload editor setting (see the Gutenberg Framework guides), but GutenbergKit uses Gutenberg's EditorProvider which overwrites that setting internally. Until GutenbergKit is refactored to use BlockEditorProvider, the api-fetch middleware approach is necessary.

Alternatives considered

JS Canvas resize + native inserter resize — Two separate implementations: createImageBitmap() + OffscreenCanvas in JS for web uploads, CGImageSourceCreateThumbnailAtIndex in MediaFileManager.import() for the native inserter. Ships fastest and lowest complexity, but Canvas resize quality is lower than native, two codepaths to maintain, and a dead-end for video (client-side transcoding in a WebView is impractical).
Native upload pipeline via local HTTP server (this PR) — A single api-fetch middleware intercepts all POST /wp/v2/media requests and routes files through a localhost server for native processing. Covers every upload path (file picker, drag-and-drop, paste, programmatic, plugin blocks) with native-quality processing. Scales to video transcoding. More upfront work than option 1.
Replace MediaPlaceholder via withFilters hook — Use editor.MediaPlaceholder and editor.MediaReplaceFlow filters with handleUpload={false} to deliver raw File objects to onSelect, then route to native. Incomplete coverage: misses block drag-and-drop re-uploads (handleBlocksDrop calls mediaUpload directly), direct mediaUpload calls from plugins, and loses blob previews when handleUpload is false. instanceof FileList checks are fragile in WebView contexts.
Redirect to native UI on large files — Keep the web upload button, but show a native dialog when files exceed limits. Awkward UX (user already picked a file, now asked to pick again differently). On iOS, the already-selected JS File can't be handed to native for optimization. Two parallel upload paths add complexity.
JS resize for images + hide web upload for video blocks — JS Canvas resize for images, hide the "Upload" button on video-accepting blocks via editor.MediaPlaceholder filter (forcing users to Media Library for video). Users can't drag-and-drop videos, blocks accepting both image and video (Cover) get complicated, and it's a dead-end architecture.
Client-side processing via @wordpress/upload-media (WASM libvips) — Gutenberg's experimental @wordpress/upload-media package includes a WASM build of libvips for high-quality client-side image resizing, rotation, format transcoding, and thumbnail generation. Quality is comparable to server-side ImageMagick. However, it requires SharedArrayBuffer for WASM threading, which is only available in cross-origin isolated contexts — WKWebView loads GutenbergKit's HTML locally with no HTTP headers, so SharedArrayBuffer is unavailable. WebKit also lacks credentialless iframe support, meaning cross-origin isolation would break third-party embeds (YouTube, Twitter, etc.). Single-threaded WASM fallback is unvalidated, and the package's memory footprint (50-100MB+ per image) is a concern under iOS jetsam pressure. Not viable today, but worth revisiting if the package decouples its store/queue management from WASM processing (tracked upstream).

A key constraint is platform asymmetry: Android can intercept web <input type="file"> via onShowFileChooser(), but iOS cannot — WKWebView handles file selection internally. This rules out purely native interception strategies for web-originated uploads and motivated the localhost server approach, which works identically on both platforms.

Testing Instructions

Open the iOS or Android demo app connected to a WordPress site (e.g., wp-env)
Verify the "Enable Native Media Upload" toggle is present and defaults to on
Insert an Image block and upload a large image (>2000px)
Verify the upload succeeds and the image displays in the editor
Check logs for "Resized image from WxH to fit 2000px" confirming native processing
Toggle "Enable Native Media Upload" off, restart the editor, and upload again — verify the upload still works (via standard Gutenberg path, no resize log)

Accessibility Testing Instructions

The toggle follows the same pattern as the existing "Enable Native Inserter" toggle — no new UI beyond that.

Screenshots or screencast

N/A — backend/infrastructure change with no visible UI changes beyond the demo app toggle.

jkmassel · 2026-03-10T20:35:36Z

+				return response.text().then( ( body ) => {
+					const message =
+						response.status === 413
+							? `The file is too large to upload. Please choose a smaller file.`


We should probably print whatever the server sends back – it should be WP_Error-shaped, but some hosts might have messaging like "The max is ${SOME_NUMBER}" or "You've reached your quota".

WDYT?

Yes, that makes sense.

This was strictly implemented to handle the 250 MB maximum upload restriction of the local server, but I agree it should be made more robust. If we do not add specific handling for 413, the default user-facing message is something like "Unable to get a valid response from the server."

Addressed in 8c78c1a and a3ff56c by removing this JS logic entirely.

dcalhoun · 2026-03-27T21:03:18Z

@jkmassel this now relies upon the GBK HTTP server library. This is ready for another review.

dcalhoun · 2026-04-09T19:43:45Z

@jkmassel the latest changes tested well for me. I believe this is ready for another review. 🙇🏻‍♂️

…dleware Add nativeMediaUploadMiddleware that intercepts POST /wp/v2/media requests when a native upload port is configured in GBKit. The middleware forwards uploads to the local HTTP server with Relay-Authorization bearer token auth, then transforms the native response into the WordPress REST API attachment shape. Includes user-friendly error handling for 413 (file too large) and generic upload failures. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add MediaUploadServer backed by the GutenbergKitHTTP library, which handles TCP binding, HTTP parsing, bearer token auth, and multipart parsing. The upload server provides a thin handler that routes file uploads through a native delegate pipeline for processing (e.g. image resize, video transcode) before uploading to WordPress. - MediaUploadDelegate protocol with processFile and uploadFile hooks - DefaultMediaUploader for WordPress REST API uploads with namespace support - EditorViewController integration with async server lifecycle - GBKitGlobal nativeUploadPort/nativeUploadToken injection - GutenbergKitHTTP added as dependency of GutenbergKit target Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add MediaUploadServer backed by the HttpServer library, which handles TCP binding, HTTP parsing, bearer token auth, and connection management. The upload server provides a thin handler that routes file uploads through a native delegate pipeline for processing (e.g. image resize, video transcode) before uploading to WordPress. - MediaUploadDelegate interface with processFile and uploadFile hooks - DefaultMediaUploader for WordPress REST API uploads with namespace support - GutenbergView integration with synchronous server lifecycle - GBKitGlobal nativeUploadPort/nativeUploadToken injection - org.json test dependency added Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add DemoMediaUploadDelegate implementations that resize images to a maximum dimension of 2000px before upload. Includes a toggle in the site preparation screen to enable/disable native media upload processing. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Integration tests covering server lifecycle, bearer token auth (407 on missing/wrong token), CORS preflight, routing (404 for unknown paths), delegate processing pipeline, and fallback to default uploader. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Integration tests covering server lifecycle, bearer token auth (407 on missing/wrong token), CORS preflight, routing (404 for unknown paths), delegate processing pipeline, fallback to default uploader, DefaultMediaUploader request format, and error handling for bad requests and non-multipart content types. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Tests covering passthrough behavior (missing port, non-POST, non-media paths, sub-paths, non-FormData), upload interception with Relay-Authorization auth, response transformation to WordPress REST API shape, error handling (413 file too large, generic failures), and abort signal forwarding. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add LocalizedError conformance to EditorHTTPClient.ClientError so that WordPress error messages (e.g. "This file is too large. The maximum upload size is 10 KB.") are surfaced to the user instead of a cryptic Swift type description. Remove the dead 413-specific handling from the JS middleware — the HTTP library rejects oversized uploads at the connection level (never producing an HTTP response the browser can read), so the 413 branch was unreachable. All upload errors now go through the generic path which includes the server's error message. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…ponses Parse the WordPress JSON error body to extract the message field (e.g. "This file is too large. The maximum upload size is 10 KB.") instead of showing the raw JSON in the upload failure snackbar. Falls back to the raw body for non-JSON error responses. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Compose corsPreflightResponse() from the shared corsHeaders constant instead of re-declaring origin and allowed-headers values. Also removes a redundant "what" comment on the multipart parsing call. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…ment Guard the mediaUploadDelegate setter with an identity check so that assigning the same delegate instance does not needlessly stop and restart the upload server. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: Avoid "native" term in user-facing errors messages The term "native" is likely unfamiliar to users, provides no tangible value, and may cause confusion. * fix: drain oversized request body before sending 413 response When Content-Length exceeds maxBodySize, the server now reads and discards the full request body before responding with 413. This ensures the client (WebView fetch) receives the error response cleanly instead of a connection reset (RFC 9110 §15.5.14). Adds a `.draining` parser state that tracks consumed bytes without buffering them, keeping memory and disk usage at zero for rejected uploads. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix: include CORS headers on server-generated error responses Add an errorResponseHeaders parameter to HTTPServer (iOS) and HttpServer (Android) so that callers can specify headers to include on all server-generated error responses (413, 407, 408, etc.). MediaUploadServer passes its CORS headers through this parameter so the browser does not block error responses due to missing Access-Control-Allow-Origin. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Revert "fix: include CORS headers on server-generated error responses" This reverts commit 0b6c67b. * fix: route 413 response through handler for CORS headers Instead of the HTTP server library building 413 responses directly (which lacked CORS headers), payloadTooLarge is now treated as a non-fatal parse error. parseRequest() returns the parsed headers as a partial request and exposes the error via a new parseError property. The server passes it to the handler via a serverError field on the request, letting MediaUploadServer build the response with CORS headers — consistent with how OPTIONS preflight is handled. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * perf(ios): stream multipart upload body from disk instead of memory Replace Data(contentsOf:) + httpBody with a streaming InputStream via httpBodyStream in DefaultMediaUploader. The multipart body (preamble, file content, epilogue) is written through a bound stream pair on a background thread, keeping peak memory at ~65 KB regardless of file size — down from ~2x file size previously. Android already streams via OkHttp's file.asRequestBody() and needs no changes. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * perf: passthrough upload when delegate does not modify the file When the delegate's processFile returns the original file unchanged (e.g., GIFs, non-images, files already within size limits), the original request body is forwarded directly to WordPress — skipping multipart re-encoding and the extra file read. Detection: after processFile, compare the returned URL/File to the input. If unchanged and uploadFile returns nil, signal passthrough back to handleUpload which streams the original body via passthroughUpload(). Also extracts shared response parsing into performUpload() on both platforms to avoid duplication between upload() and passthroughUpload(). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * refactor(android): fix Detekt lint violations Extract readUntil() helper from HttpServer.handleRequest() to reduce nesting depth and throw count. Extract performPassthroughUpload() from MediaUploadServer.processAndRespond() to consolidate throw statements. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix(ios): prevent integer overflow in drain mode byte tracking Cast `bytesWritten` and `offset` to Int64 individually before subtracting, avoiding a potential Int overflow when the difference is computed before the widening cast. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * refactor(ios): replace deprecated URL.path with path(percentEncoded:) URL.path is deprecated on iOS 16+. Use path(percentEncoded: false) to get the file system path without percent-encoding. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * refactor(ios): localize "file too large" error via EditorLocalization Add a `fileTooLarge` case to `EditorLocalizableString` so host apps can provide translations for the 413 error message. The hardcoded string in MediaUploadServer now reads from the localization system. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Revert "refactor(ios): localize "file too large" error via EditorLocalization" This reverts commit 71440d9. * fix(ios): review adjustments for #419 (#441) * fix(ios): use Int64 for HTTPRequestParser.bytesWritten Change `bytesWritten` from `Int` to `Int64` for consistency with `expectedContentLength` and `maxBodySize`, which are already `Int64`. * test(ios): add end-to-end test for 413 response with CORS headers Expose maxRequestBodySize on MediaUploadServer.start() and add an integration test that sends an oversized request and verifies the response includes both a 413 status and CORS headers. * fix(test): increase maxRequestBodySize for 413 test The multipart overhead (~191 bytes) plus auth headers meant the previous limit of 100 bytes caused the connection to reset before the drain could complete. Use 1024 bytes with a 2048-byte payload so the parser can drain the body and deliver the 413 response. * fix(test): use raw TCP for 413 test to avoid URLSession connection reset URLSession treats a server response during upload as a connection error (NSURLErrorNetworkConnectionLost). Use a raw NWConnection to send the request and read the response directly, which correctly receives the 413 with CORS headers. * fix: complete drain immediately when body arrives with headers When the entire HTTP request (headers + body) arrives in a single read, the parser enters DRAINING but never completes because the body bytes were already counted in bytesWritten. Subsequent reads find no more data, causing a timeout. Check the drain condition immediately when entering the draining state, transitioning to complete if all body bytes have already been received. Fixes both iOS and Android parsers. --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com> Co-authored-by: Jeremy Massel <1123407+jkmassel@users.noreply.github.com>

wpmobilebot · 2026-07-09T18:21:10Z

XCFramework Build

This PR's XCFramework is available for testing. Add the following to your Package.swift:

.package(url: "https://github.com/wordpress-mobile/GutenbergKit", branch: "pr-build/357")

_{Built from 4521918}

… CORS) (#546) * fix: fall back to default upload path when native server is unreachable The native media upload middleware rethrew on any fetch failure, so a local upload server that was never started, restarted on a new port, or torn down turned every upload into a hard failure. Distinguish a connection-level failure (fall back to next()) from a non-ok response (a real server error that must surface), and re-throw AbortError so an explicit cancellation is not retried. Amplifier fix for the iOS/Android upload-server lifecycle issues. * fix(ios): stop upload server on deinit and hold the delegate weakly viewDidDisappear fires whenever another view controller is pushed or presented over the editor. HTTPServer.stop() cancels the NWListener, which is terminal, so uploads stayed broken after the user returned. Move stop() to deinit. Hold the media upload delegate weakly in UploadContext (re-read per request): mediaUploadDelegate is declared weak, and the strong capture both defeated that contract and risked a retain cycle that kept the view controller — and the server — alive so deinit never fired. * fix(android): re-advertise upload server port and token on restart setGlobalJavaScriptVariables only runs from onPageStarted, so when the media upload delegate setter restarts the server after the page has loaded (e.g. a Compose host constructing a new delegate instance per recomposition), the new port and token were never injected and JS kept fetching a dead port. Patch the two fields into window.GBKit after each (re)start; the window.GBKit guard makes it a no-op before the page loads, where onPageStarted still handles the initial injection. * fix(android): use a 60s timeout for media uploads The upload OkHttpClient used the bare defaults, including a 10s read timeout. WordPress generates image sub-sizes synchronously inside POST /wp/v2/media, so >10s responses are routine on shared hosting — and because the attachment row is created before sub-size generation, a client-side timeout orphans the attachment server-side and duplicates it on retry. Match EditorHTTPClient's 60s policy. * fix(android): return CORS headers on all upload error responses processAndRespond only caught MediaUploadException; an IOException from the upload call, JSON parse errors, a throwing delegate, and "no uploader configured" escaped to HttpServer's header-less 500 fallback, so the browser rejected the preflighted cross-origin fetch with an opaque "Failed to fetch" and hid the real error from the editor. Add a catch-all mapping to the CORS-bearing errorResponse (mirroring iOS), rethrowing coroutine cancellation so it is not swallowed. * fix(android): start upload server for cookie-auth hosts with an upload delegate startUploadServer bare-returned when authHeader was empty, but empty authHeader is in-contract for cookie-auth hosts (auth via setCookies), and a delegate implementing uploadFile can own the upload without the default REST uploader. This made an uploadFile-implementing cookie-auth host silently take the unprocessed WebView path, while the same setup worked on iOS. Build the default uploader only when siteApiRoot and authHeader are present (MediaUploadServer already accepts a null default uploader), and start the server whenever a delegate can handle uploads. * fix: relay WordPress's raw upload response instead of a synthesized shape The native upload server parsed WordPress's media response into a 9-field MediaUploadResult (duplicated in Swift, Kotlin, and JS) and the JS middleware re-synthesized an attachment from it. That dropped media_details.sizes — so every native-uploaded image fell back to sizeSlug: full and embedded the full-resolution original — plus the attachment-page link, distinct raw/rendered fields, and _embedded, and flattened WordPress's status to a local 500. Replace the schema with MediaUploadResponse (status + raw body) and relay WordPress's response verbatim. DefaultMediaUploader returns the raw bytes + status and no longer throws on non-2xx (iOS via a new non-throwing EditorHTTPClientProtocol.performRaw; Android reads the OkHttp response directly). The server relays (status, body) with CORS headers, and errorResponse now emits a {code, message} JSON body so its own errors normalize like a relayed WordPress error. The JS middleware returns response.json() unchanged on success, and on a non-2xx rejects with the parsed WordPress error body (like @wordpress/api-fetch) so media-utils surfaces WordPress's real message and code, falling back to invalid_json on a non-JSON body. The uploadFile delegate now returns MediaUploadResponse? (the raw response); nil still selects the default uploader. Forwarding post/additionalData and ?_embed is a follow-up. * fix: forward media upload fields and query through the native server The native media upload middleware rebuilt the request body with only the file field and dropped the URL query, so post (the attachment's post association), any additionalData, and ?_embed never reached WordPress — the attachment was created with no post_parent and _embedded was always absent. Forward the original request body (all fields) and the original query string from JS. On the native side, carry the incoming query onto the WordPress media URL, and — on the re-encode path where processFile changed the file — preserve the non-file parts in the rebuilt multipart body. The passthrough path already forwards them verbatim once the body is relayed unchanged. Completes the finding-3/4/18 upload-fidelity work; the multipart re-encode dedup is tracked separately in #545. * fix: clean up upload temp files on failure and sweep crash orphans When processFile produced a new file but the upload failed, the processed file leaked (the caller only cleaned up the original); partial writes leaked too; and there was no sweep for files orphaned by a crash. Android also staged temp files under java.io.tmpdir instead of the injected cache dir. Clean up the processed file inside processAndUpload (defer/finally) so the throw paths are covered, and delete the original in the write-failure catch. iOS handleUpload now uses defer + straight-line do/catch instead of the Result/mutable-var dance. Android stages temp files under the injected cacheDir (system-temp fallback). Both platforms sweep upload temp files older than an hour at startup, so crash orphans are reclaimed without disturbing in-flight uploads. Findings 13 and 21. * fix: regenerate Package.resolved against the committed manifest Package.resolved pinned wordpress-rs (branch alpha-20260313), which the root Package.swift never declares — so every swift build/test pruned it and dirtied the tree. Regenerate it from the manifest. The Demo-iOS Xcode project resolves wordpress-rs through its own package reference, so this does not affect the demo. Finding 16. * refactor(ios): remove dead MediaUploadError cases and Data.append extension After the raw-relay refactor, MediaUploadError.uploadFailed/unexpectedResponse are unused (the uploader no longer parses or throws on non-2xx), leaving only streamReadFailed — which UploadError already defines. Fold the two streamReadFailed uses into UploadError and delete MediaUploadError, plus the private Data.append(String) extension the multipart builder no longer uses (the test keeps its own copy). Finding 22 (partial). * fix(android): bake EXIF orientation into resized demo images The demo resize decodes with BitmapFactory (which ignores EXIF orientation) and re-encodes via compress() (which writes no EXIF), so a portrait photo — stored with landscape pixels plus an orientation tag — uploaded rotated. Read the tag and rotate the bitmap before compressing. Demo-only, but it is the reference processFile implementation hosts copy. Finding 15. * fix: normalize the media endpoint URL for unslashed root and namespace The upload endpoint URL was built by raw concatenation, so an unslashed siteApiRoot ("...wp-json") or namespace ("sites/123") produced a malformed URL ("...wp-jsonwp/v2/..." or ".../v2/sites/123media") and a 404. Apply the same normalization RESTAPIRepository uses — trim the root's trailing slash and give the namespace a trailing slash. Latent (in-repo producers pass slashed values today). Finding 7. * fix: give processFile an explicit result with corrected metadata processFile returned a bare URL/File, and the framework inferred "did it change?" by path equality — which conflated "unchanged" with "edited in place" and gave the delegate no way to report a new filename or MIME type. So an in-place EXIF/GPS strip was silently discarded (the original body was forwarded instead), and a format-changing transcode (MOV->MP4) uploaded with the original extension and mime_type. Replace the bare return with ProcessedProxyFile (.original / .processed(url, mimeType:, filename:)). Passthrough is now explicit, so an in-place edit is uploaded rather than dropped, and the delegate reports the resulting metadata, which is used verbatim. processFile also gains a filename parameter so the delegate has the original name to echo or rewrite — without it that data was simply lost. Breaking change to the public MediaUploadDelegate; both demos updated. Findings 11 and 12. * feat: add an opt-in permissive CORS policy to the HTTP server The HTTP library generated some responses itself — the read timeout (408) and pre-handler errors — without CORS headers, so the browser blocked the WebView from reading them and a timeout surfaced as an opaque "Failed to fetch" (and, with the JS fallback, a silent re-upload). Every handler also had to remember to add CORS to its own responses. Add an opt-in cors: .permissive policy to HTTPServer (iOS) / HttpServer (Android). When enabled the library answers the OPTIONS preflight itself and stamps permissive CORS headers on every response at the single send choke point — covering handler responses and the library's own. MediaUploadServer opts in and deletes its bespoke corsHeaders / corsPreflightResponse / OPTIONS handling, so CORS lives in one place. This also de-fangs the finding-14 contract change: the library's error responses now carry CORS regardless of whether a handler inspects serverError. Default policy is .none, so existing consumers are unaffected. Findings 10 and 14. * refactor: classify parse-error disposition (fatal vs recoverable) as an enum The parser decided which parse errors abort the connection vs. are surfaced to the handler with a single implicit condition (!= payloadTooLarge), and the fixture runners accepted an expected error via EITHER channel — so a refactor routing a smuggling-relevant error (e.g. conflicting Content-Length) into the recoverable/handler path would have kept every suite green while letting a malformed request reach the handler before auth. Make the classification typed data: HTTPRequestParseError gains a Disposition (fatal / recoverable), declared per case so a new error can't compile without one, and the parser throws on disposition == fatal. A lock test pins that only payloadTooLarge is recoverable, and the fixture runners now assert the channel matches the error's disposition (threw => fatal, pendingParseError => recoverable) on both platforms. Finding 17. * refactor: extract a shared namespaced REST URL builder RESTAPIRepository's site-root/namespace normalization was duplicated by the media uploader — the one endpoint that bypassed the canonical builder, so the two could drift. Extract it to a shared, tested helper (WordPressRESTURL on iOS, RestUrlBuilder on Android) and route RESTAPIRepository through it. No behavior change; pinned by the existing repository tests plus new builder tests. * fix: harden the native media upload server - Relay non-file multipart fields (post, additionalData) as raw bytes rather than round-tripping through String, which silently mangled any non-UTF-8 value. - Build the media endpoint through the shared URL builder, and carry the request query via percentEncodedQuery on iOS so a non-URL-safe value can't drop it. - Sweep crash-orphaned temp files off the caller's thread via an injectable scope and dispatcher (cancelled on stop; tests inject Unconfined to run it inline). Tests: iOS non-2xx relay, processed-file cleanup (both platforms), orphan-sweep age threshold, and the weak-delegate lifetime that keeps deinit teardown working. * fix(android): gate the upload server on reachability and align its timeouts - Only start when a REST uploader can be built (drop the unreachable cookie-auth branch that 500'd), and clear the advertised port on stop so the JS middleware routes to the default path instead of a dead port. - Skip start when cleartext to localhost is blocked, so a misconfigured host degrades gracefully rather than failing every upload. - Drop the total callTimeout for per-operation inactivity timeouts matching URLSession (15s connect, 60s read/write) so a large upload isn't capped. - Post the JS port/token sync to the WebView's UI thread. * fix: drop the media-upload fallback and relay errors faithfully The connection-error fallback re-ran a non-idempotent POST /wp/v2/media, which could duplicate an attachment, and pointed the wrong way under Lockdown Mode. Reachability is now gated natively, so remove it. Detect cancellation via signal.aborted and rethrow signal.reason (catches AbortSignal.timeout, not just AbortError). Normalize a non-JSON 2xx body to invalid_json like the non-ok path. * fix(android): report the re-encoded image type in the demo delegate The resize demo normalizes everything but PNG to JPEG (Bitmap.compress can't round-trip WebP/HEIC), but returned the original mime/filename — so a WebP upload was JPEG bytes labelled image/webp, which WordPress rejects. Report the actual output type and extension. * fix: route the upload server on the path, not the full target (#557) * feat(http): add path and query accessors to parsed requests The request target carries both the path and the query string, so callers that want to route on the path have to split it themselves. Expose `path` and `query` on both platforms' request types instead. A bare trailing "?" yields an empty query on both platforms, so the value can be appended to an upstream URL unconditionally. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> * fix: route the upload server on the path, not the full target Media uploads fail with a 404. `@wordpress/media-utils` uploads to `/wp/v2/media?_embed=wp:featuredmedia`, and the middleware now forwards that query on to the native server so it can be relayed to WordPress. The route guard still compared the full request target against "/upload", so a query string made it miss and return 404 before the upload handler ever ran. Match on `path` instead, and take the relayed query from `query` rather than re-deriving it in the handler. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> * fix(upload): normalize a bare trailing "?" to an empty query The native `query` accessors treat a bare trailing "?" as carrying no parameters and yield an empty string, so the value can be appended to an upstream URL unconditionally. The middleware that produces the target still derived the query with `indexOf`/`slice`, which keeps the "?" — `/wp/v2/media?` became `POST /upload?`, a target both platforms document as impossible. Extract `requestQuery` so the rule is stated once on this side and named against its native counterparts. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> * test(upload): pin which upload branch relays the query Both `upload` and `passthroughUpload` record `lastQuery` on the mock, so asserting the query alone passes whichever branch ran — a regression that collapsed routing onto one path would still go green. Assert the passthrough branch explicitly, matching the sibling tests. Forcing `processFile` to return `.processed` now fails these tests; the query assertion alone did not. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> * refactor(http): express `path` with prefix(upTo:) The explicit `startIndex..<separator` range says the same thing as `prefix(upTo:)` with more moving parts, and reads further from its Android counterpart (`substringBefore`). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com> --------- Co-authored-by: David Calhoun <github@davidcalhoun.me> Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

… feat/leverage-host-media-processing # Conflicts: # ios/Sources/GutenbergKit/Sources/EditorHTTPClient.swift # ios/Sources/GutenbergKit/Sources/EditorViewController.swift

Two fixes to `nativeMediaUploadMiddleware`, both aligning it with the existing `mediaUploadMiddleware` it short-circuits past. Strip the `post` field when it is the auto-draft sentinel (`-1`). WordPress rejects attaching media to post `-1`, and because this middleware returns the relay fetch without calling `next()`, `mediaUploadMiddleware` (which normally strips the sentinel) never runs — so the value reached WordPress verbatim and broke uploads on the common new-post flow. Require `nativeUploadToken` in the activation guard. The server always requires authentication, so a port-without-token state would send `Bearer undefined` and 407 instead of falling through to the default upload path. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

`startUploadServer` built `DefaultMediaUploader` whenever a media upload delegate was set, ignoring whether an auth header was present. It uploads to `/wp/v2/media` with the host's `Authorization` header (the WebView has none of its own), so with an empty header every relayed upload would 401 instead of falling back to the default WebView path. Guard on a non-empty auth header before starting the server, matching the Android guard in `GutenbergView.startUploadServer`. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

`writeStream` force-unwrapped `OutputStream(url:append:)`, which returns nil if the file can't be opened for writing (uploads directory removed after creation, or a permissions/sandbox failure). That trapped and crashed the process instead of returning the clean 500 the caller already builds. Throw `streamWriteFailed` so it flows into the existing do/catch — temp file removed, 500 relayed to the editor. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Partially reverts 93aa2d1. api-fetch runs middleware in reverse registration order, so `mediaUploadMiddleware` (registered later) runs first and has already stripped the auto-draft `post: -1` sentinel by the time `nativeMediaUploadMiddleware` runs — the strip was dead code based on an inverted ordering assumption. The `nativeUploadToken` guard from that commit remains. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The oversized-payload path (drain plus serverError handler dispatch) ran before the bearer-token check, so unauthenticated clients could make the server read an arbitrarily large declared body and reach the handler. Reorder the connection flow on both platforms so auth is validated on headers alone first: unauthenticated oversized requests are rejected with an immediate 407, while authenticated ones keep the full drain and CORS-stamped 413 (RFC 9110 §15.5.14). Add regression tests pinning the ordering — an unauthenticated oversized request must return 407, not the handler's 413. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

HTTPServer.start awaited NWListener readiness with no bound and treated .waiting as "keep waiting" — a listener stuck in that state (which emits no further updates) suspended the caller forever. Since the editor awaits the upload server start before loading the WebView, a stuck listener blocked editor startup indefinitely behind the activity spinner. Race the readiness wait against a startTimeout (default 5s; loopback binds normally complete in milliseconds) and throw failedToStart on expiry, cancelling the half-started listener. Callers already degrade gracefully on failedToStart, falling back to the default upload path. The wait is extracted into an internal firstTerminalState helper because a stuck listener cannot be reproduced deterministically with a real NWListener — tests feed it a hand-built state stream instead. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The fast path (dependencies provided at init) became an async Task when loadEditor started awaiting the upload server, and it was tracked in dependencyTaskHandle — which viewDidDisappear cancels. A transient disappearance (e.g. a full-screen modal presented right after the editor) cancelled the load mid startUploadServer(), surfacing as failedToStart and silently disabling native uploads for the session with no retry. Run the fast path untracked: the disappear-cancel exists to abort the async dependency *fetch*, while the fast path is cheap local work that must run to completion — restoring the guarantee it had when it was synchronous. The weak self capture still makes it a no-op after teardown. Leaving the task untracked is safe because the preceding commit bounds the upload server's listener readiness wait (startTimeout) — the only await here that could hang — so the task always terminates. Reverting that commit alone would reintroduce an unbounded, now-uncancellable suspension on this path. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Both startup sweeps — cleanOrphanedUploads in MediaUploadServer.start and cleanOrphanedTempFiles in HTTPServer.start — ran synchronous directory scans on the editor-load critical path. Detach them to a utility-priority task instead, mirroring Android's cleanupJob; each server exposes the task so tests can await completion. Detaching cleanOrphanedTempFiles required giving it the same one-hour age threshold the upload sweep already uses: it previously deleted every file in the server's temp subdirectory, which a detached sweep could race against a live instance's in-flight temp buffers. The threshold also removes the documented hazard of same-name instances wiping each other's files. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

dcalhoun · 2026-07-22T16:13:28Z

-            // Drain oversized body before throwing so the
-            // client receives the 413 (RFC 9110 §15.5.14).
-            if (parser.state == HTTPRequestParser.State.DRAINING) {
-                readUntil(parser, input, buffer, deadlineNanos) { it.isComplete }
-            }


Relocated to avoid unauthorized requests causing body drains. Similar iOS changes added around ios/Sources/GutenbergKitHTTP/HTTPServer.swift:285.

dcalhoun · 2026-07-22T16:15:22Z

+    /// The default maximum time to wait for the listener to become ready (5 seconds).
+    /// Binding to loopback normally completes in milliseconds; the bound exists so a
+    /// listener stuck in the `.waiting` state (which emits no further updates)
+    /// cannot suspend its caller indefinitely.
+    public static let defaultStartTimeout: Duration = .seconds(5)


Added in 7da893b to avoid media upload server start delays from indefinitely postponing editor launch. I welcome feedback on the implementation.

dcalhoun · 2026-07-22T16:16:39Z

+            // Deliberately NOT tracked in `dependencyTaskHandle`: `viewDidDisappear`
+            // cancels that handle to abort the async dependency *fetch*, but the
+            // fast path is cheap local work that must run to completion — a
+            // transient disappearance (e.g. a modal presented over the editor)
+            // cancelling it mid `startUploadServer()` silently disabled native
+            // uploads for the session. `[weak self]` still makes it a no-op once
+            // the controller is torn down.
+            Task(priority: .userInitiated) { [weak self] in


Added in f1ce3cc. Based on my understanding, this seems correct. I welcome help confirming that.

dcalhoun · 2026-07-22T16:18:38Z

+        // Sweep temp files orphaned by a prior crash, off the editor-startup
+        // path — the sweep only deletes stale files (>1 hour old), so it cannot
+        // race this server's own in-flight uploads and nothing below depends on it.
+        let cleanupTask = Task.detached(priority: .utility) {
+            cleanOrphanedUploads()
+        }


Added in 4521918. I believe moving this to a Task is sound for improving editor startup time, but I welcome a second glance to ensure this doesn't cause issue.

dcalhoun · 2026-07-22T16:30:40Z

+            // Drain the oversized body before responding so the (authenticated)
+            // client receives the 413 instead of a connection reset
+            // (RFC 9110 §15.5.14).
+            if (parser.state == HTTPRequestParser.State.DRAINING) {
+                readUntil(parser, input, buffer, deadlineNanos) { it.isComplete }
+            }


Relocated in acea3f5 to avoid unauthorized requests causing body drains. Similar iOS changes added around ios/Sources/GutenbergKitHTTP/HTTPServer.swift:285.

Points GutenbergKit at the XCFramework snapshot for wordpress-mobile/GutenbergKit#357, which adds the native media upload server and MediaUploadDelegate. Swap to a tagged release before merge.

dcalhoun added the [Type] Enhancement A suggestion for improvement. label Mar 9, 2026

github-advanced-security AI found potential problems Mar 9, 2026

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Comment thread android/Gutenberg/src/main/java/org/wordpress/gutenberg/MediaUploadServer.kt Fixed

github-advanced-security AI found potential problems Mar 9, 2026

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Comment thread android/Gutenberg/src/main/java/org/wordpress/gutenberg/MediaUploadServer.kt Fixed

dcalhoun force-pushed the feat/leverage-host-media-processing branch from df05265 to 64d64cb Compare March 9, 2026 17:33

dcalhoun marked this pull request as ready for review March 10, 2026 01:24

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feat: add cross-platform HTTP/1.1 parser and local proxy server for iOS and Android #367

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dcalhoun changed the title ~~feat: route media uploads through native host for processing~~ feat: proxy media uploads through native delegate for processing Mar 23, 2026

dcalhoun force-pushed the feat/leverage-host-media-processing branch 2 times, most recently from 5a78344 to 18f81b7 Compare March 27, 2026 19:27

dcalhoun commented Mar 27, 2026

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Comment thread ios/Sources/GutenbergKit/Sources/Media/MediaUploadServer.swift Outdated

Comment thread src/utils/api-fetch.js Outdated

dcalhoun requested a review from jkmassel March 27, 2026 21:03

This was referenced Apr 2, 2026

fix(android): use ACTION_OPEN_DOCUMENT to avoid ERR_UPLOAD_FILE_CHANGED #415

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fix: improve upload server error handling and memory efficiency #419

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dcalhoun assigned jkmassel Apr 10, 2026

dcalhoun and others added 12 commits July 9, 2026 11:46

jkmassel force-pushed the feat/leverage-host-media-processing branch from 8b4b5ab to 6b1d98b Compare July 9, 2026 18:09

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Add a multipart encoder to GutenbergKitHTTP and delete the duplicated multipartBodyStream #545

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jkmassel force-pushed the feat/leverage-host-media-processing branch from 7758c5b to 6b1d98b Compare July 10, 2026 19:02

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fix: native media upload review follow-ups (relay, delegate contract, CORS) #546

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jkmassel and others added 10 commits July 21, 2026 17:07

Merge branch 'trunk' of github.com:wordpress-mobile/GutenbergKit into…

d0b3f08

… feat/leverage-host-media-processing # Conflicts: # ios/Sources/GutenbergKit/Sources/EditorHTTPClient.swift # ios/Sources/GutenbergKit/Sources/EditorViewController.swift

dcalhoun commented Jul 22, 2026

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feat: process New Block Editor media uploads with app Media settings wordpress-mobile/WordPress-iOS#25824

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jkmassel mentioned this pull request Jul 22, 2026

fix: harden the native media upload server (review of #357) #561

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dcalhoun mentioned this pull request Jul 23, 2026

feat: process GutenbergKit media uploads per the app's media settings wordpress-mobile/WordPress-Android#23142

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