cloudflare/workerd

The JavaScript / Wasm runtime that powers Cloudflare Workers

Stars: 8.7k
Forks: 739
Open beginner issues: 0
Indexed issues: 464
Avg merge: 2d 20h
Merged PRs (30d): 174

Dominant language: C++
License: Apache-2.0
Last GitHub push: Sep 14, 2026
Latest indexed: Sep 15, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: good first issue

Open All

464 open issues indexed

Local dev: containers never start on hosts with net.ipv4.conf.all.src_valid_mark=1 (e.g. Tailscale) — sidecar handshake packets dropped as martians Open

cloudflare/workerd#6860 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Tail Workers implicitly activate node:diagnostics_channel publishers and add unrequested overhead Open

cloudflare/workerd#6861 · 10 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: setAlarm Open

cloudflare/workerd#6866 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🚀 Feature Request: Source map support for Worker Loader (dynamic workers) stack traces Open

cloudflare/workerd#6870 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
JS RPC: pipelined calls fail with "The RPC receiver does not implement the method" when a method returns a Proxy-wrapped RpcTarget (awaited stub works; path traversal already special-cases Proxies) Open

cloudflare/workerd#6873 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Buffer.prototype.utf8Write` (and all other `*Write` methods) throw `ERR_OUT_OF_RANGE` when `length` is omitted and `offset > 0` Open

cloudflare/workerd#6875 · 0 comments · 4 reactions · 0 assignees · Indexed Sep 15, 2026
Support MKCALENDAR requests at Worker ingress Open

cloudflare/workerd#6877 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
feat: impl `node:sqlite` {Database,Statement}Sync with Durable Objects Open

cloudflare/workerd#6878 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Include the creation stack trace in the "RPC stub/result was not disposed properly" warning Open

cloudflare/workerd#6879 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Workflow id initialized to a non-UUID Open

cloudflare/workerd#6885 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
node:dns lookup() returns CNAME records as IPv4/IPv6 LookupAddress entries Open

cloudflare/workerd#6886 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs Open

cloudflare/workerd#6889 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs Open

cloudflare/workerd#6890 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`crypto.subtle.exportKey()` returns absent `JsonWebKey` members as enumerable `undefined` properties Open

cloudflare/workerd#6892 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Unbounded native memory growth from repeated cross-worker fetch() subrequests (uncollected receiver-isolate garbage) Open

cloudflare/workerd#6894 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: workerd bug in Buffer.prototype.utf8Write under nodejs_compat Open

cloudflare/workerd#6897 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Workflows: type the errors thrown by the binding (stable codes + documented list) Open

cloudflare/workerd#6899 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Hyperdrive.connect() crashes the whole process with SIGSEGV when the binding's designator points at a Worker service instead of an external service Open

cloudflare/workerd#6901 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`startTls({ expectedServerHostname })` is ignored on the production edge — no SNI is sent Open

cloudflare/workerd#6903 · 1 comment · 7 reactions · 0 assignees · Indexed Sep 15, 2026
Generated TypeScript declarations omit receiver requirements enforced by JSG/V8 Open

cloudflare/workerd#6904 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
node:crypto.argon2 not supported Open

cloudflare/workerd#6906 · 3 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — node:dns resolveCaa/resolveNaptr throw after the 1.1.1.1 DoH JSON presentation-format rollout Open

bug nodejs compat

cloudflare/workerd#6912 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report: `std::terminate() called with no exception` when a tail consumer's target process dies abruptly (Windows) Open

cloudflare/workerd#6913 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report Runtime APIs node:crypto: Cipheriv.prototype.update throws when string is passed without inputEncoding Open

cloudflare/workerd#6920 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report Runtime APIs node:crypto: Hmac.prototype.digest silently returns empty Buffer on second call instead of throwing ERR_CRYPTO_HASH_FINALIZED Open

cloudflare/workerd#6921 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report Runtime APIs node:buffer: Buffer.alloc and Buffer.allocUnsafe throw ERR_OUT_OF_RANGE for size === kMaxLength (off-by-one) Open

cloudflare/workerd#6922 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Node.js Compat API Update Survey Open

cloudflare/workerd#6924 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Workflows: caught waitForEvent timeout emits false "Worker code had hung" cancellation Open

cloudflare/workerd#6925 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Workers Logs loses Error name/message after `workerd` errorInfo stack normalization Open

cloudflare/workerd#6926 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Received header values are UTF-8 decoded instead of exposed as byte strings, losing bytes that are not valid UTF-8 Open

cloudflare/workerd#6927 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: node:zlib zstd ignores the dictionary option (silent on compress, "Data corruption detected" on decompress) Open

cloudflare/workerd#6967 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Bundled worker modules have undefined import.meta.url, crashing fileURLToPath(import.meta.url) callers Open

cloudflare/workerd#6986 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Implement `remove_nodejs_compat_eol_v26` (and 25) for Node 26 Open

cloudflare/workerd#7003 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
WASI P3 Support? Open

cloudflare/workerd#7022 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
workers-types declares Buffer and process as const, discarding the @types/node globals Open

cloudflare/workerd#7026 · 2 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
When a promise is aborted using AbortSignal, the reason of the abort is not preserved Open

wpt-conformance

cloudflare/workerd#7035 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: fetch requests to external endpoints without the X25519MLKEM768 key group raise 525 errors, connect() works fine Open

cloudflare/workerd#7042 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Responses with multiple `Content-Encoding` headers not decompressed Open

cloudflare/workerd#7051 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: `encodeBody: "manual"` is silently dropped when a Response is rebuilt with an object init, double-encoding the body Open

cloudflare/workerd#7066 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Single TCP socket write() larger than 64 KiB silently destroys the connection (production runtime only) Open

cloudflare/workerd#7074 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
IMAGES.input(ArrayBuffer)` is treated as `text()` and throws `Cannot read properties of undefined (reading 'font') Open

cloudflare/workerd#7097 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: Images binding crashes with "Cannot read properties of undefined (reading 'font')" when input() is given an ArrayBuffer Open

cloudflare/workerd#7126 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: `node:stream` on workerd drops a `'readable'` event under a reentrancy-guarded reader with manual backpressure Open

cloudflare/workerd#7136 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Feature request: support configuring `HttpServerSettings::pipelineTimeout` Open

cloudflare/workerd#7169 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Support scheduled / cron triggers in standalone workerd Open

cloudflare/workerd#7188 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Bug: Durable Object alarm firing under `durableObjectStorage = (inMemory = void)` crashes the workerd process Open

cloudflare/workerd#7190 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Bug: Durable Object alarm firing under `durableObjectStorage = (inMemory = void)` crashes the workerd process Open

cloudflare/workerd#7191 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
fetch() network failures reject with Error instead of TypeError Open

cloudflare/workerd#7195 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: node:tls key/cert are documented but ignored Open

cloudflare/workerd#7201 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
🐛 Bug Report — Runtime APIs: Socket `closed`/stream-EOF promises never settle at IoContext teardown, permanently leaking AsyncLocalStorage frames via pending reactions Open

cloudflare/workerd#7202 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026

A short digest of beginner-friendly GitHub issues.