Rebase fork onto cloudflare/capnweb v0.10.0 (drop fallbackCall)

[jonastemplestein]

What this is

This rebases the iterate capnweb fork onto the latest cloudflare/capnweb main (bc4bc45, v0.10.0). Our previous base was 3d17ba1 (v0.8.1 era, ~27 upstream commits behind).

Because this is a rebase, the branch shares no commits with the current main — GitHub will report merge conflicts, and that is expected. Do not merge via the UI. After approval, integrate with:

git push origin rebase-0.10:main --force-with-lease

(requires temporarily allowing force-push on main, or an admin push). The PR diff you see here is the full delta that lands on main: everything upstream shipped since our old base, plus our fork commits replayed on top.

What we pick up from upstream (0.8.1 → 0.10.0)

• capnweb-validate (Add capnweb-validate RPC validators cloudflare/capnweb#169, fix(validate): support decorated classes extending decorated classes cloudflare/capnweb#194, Skip validation for fetch and connect lifecycle methods on WorkerEntrypoint and DurableObject. cloudflare/capnweb#197): new workspace package — build-time TypeScript transform that generates runtime validators for RPC targets. The repo is now an npm workspace (root + packages/*).
• Receiver-side resource limits (Deserializing untrusted bigint values can cause CPU exhaustion cloudflare/capnweb#184/Add receiver-side resource limits for untrusted peers (#184) cloudflare/capnweb#185): RpcLimits (maxBigIntDigits, maxDepth, maxMessageSize) guard against resource-exhaustion from untrusted peers; configurable via RpcSessionOptions.limits.
• Transport encoding levels (feat: add encoding levels to RPC transport cloudflare/capnweb#144/Finish RPC transport encoding levels from #144 cloudflare/capnweb#186): transports can now receive jsonCompatible / jsonCompatibleWithBytes / structuredClonable values instead of JSON strings (RpcTransportWithCustomEncoding).
• Five serialization/transport correctness fixes (Fix five correctness and robustness issues in serialization and transport handling cloudflare/capnweb#190): prototype-pollution filtering on deserialized error properties, null-prototype error-type map (type-confusion fix), duplicate-resolution leak fix, unwrapped abort reasons, WebSocket close-reason truncation.
• ArrayBuffer and TypedArray views serialization (feat: Support ArrayBuffer and Buffer Views serialization cloudflare/capnweb#201), widened ReadableStream chunk type (Widen ReadableStream RPC chunk type to any RPC-compatible value cloudflare/capnweb#214), streaming WritableStream writes with lifecycle-managed payloads (feat: support streaming WritableStream writes with lifecycle-managed RPC payloads cloudflare/capnweb#212).
• 405 for non-POST batch requests (fix(batch): add missing early return in nodeHttpBatchRpcResponse on non-POST cloudflare/capnweb#195), audit dependency patches (chore: patch relevant audit vulnerabilities cloudflare/capnweb#218), CI updates.

Fork commits carried (in order)

1. Add support for sending WebSockets over RPC, as part of a fetch upgrade Response — the reason this fork exists. A Workers-style upgrade Response (with a webSocket property) can be passed over RPC, tunneled as a pair of streams (src/websocket-streams.ts, plus serialize.ts/core.ts integration and protocol.md documentation).
2. Add a prepare script so git dependencies get a build.
3. Add a server-side per-call RPC hook — RpcSessionOptions.onCall wraps every local application function invoked by the peer, propagating through promise pipelining. Used by iterate/iterate for ITX observability (apps/os/src/itx/itx-observability.ts).
4. Publish as @iterate-com/capnweb with pkg.pr.new and npm release CI — package rename, fork README banner, tag-driven npm release workflow, pkg.pr.new previews on main + PRs.
5. Sync package-lock name to @iterate-com/capnweb.
6. Remove Cloudflare-internal CI workflows from the fork (new in this rebase) — upstream added Bonk (their AI PR reviewer, needs Cloudflare AI Gateway secrets, not org-gated → every iterate PR would get a failing check) and a CLA assistant (pull_request_target → would demand Cloudflare CLA signatures from iterate contributors). Both dropped; semgrep.yml and test.yml kept — they run without secrets.

Dropped: the fallbackCall feature

The previous main carried four commits implementing an opt-in [fallbackCall] symbol for dynamic RPC paths (plus the 17k-line examples/dynamic-capabilities example). iterate/iterate has zero references to it (verified via git grep — only onCall is used), so per Jonas it is dropped rather than rebased. It remains recoverable from the old main history if ever needed.

Notable conflict resolutions / merge decisions

• Evaluator (serialize.ts): upstream added encodingLevel + depth-tracked evaluation (evaluateWithDepth) for limits; our fork threads a callHandler through the same constructor. Merged as constructor(importer, encodingLevel, callHandler); pipelined-call sub-evaluators pass all three. One real bug caught by test:types during the rebase: our WebSocket readable evaluation was missing upstream's new depth argument — fixed (serialize.ts:1076), so tunneled sockets participate in maxDepth enforcement.
• RpcSessionOptions: keeps both upstream's limits and our onCall. The hook is threaded into the two call-evaluation sites (push + batch) only — resolution/reject/abort evaluation paths intentionally don't get it, matching the original fork design.
• core.ts: our getHookForReturn consolidation + WebSocket hook tracking (sentWebSockets, getHookForWebSocket, dispose-time socket close) replayed cleanly over upstream's stream-hook methods.
• Workflows: kept the fork's release.yml (tag-driven npm publish with OIDC/NPM_TOKEN) and pkg-pr-new.yml (push-to-main + PRs) semantics, adopted upstream's action upgrades (checkout@v7, setup-node@v6, Node 24).
• package.json: @iterate-com/capnweb at upstream's 0.10.0; workspace config from upstream; both prepare and prepublishOnly build. README fork banner updated to reference 0.10.0.
• package-lock.json: took upstream's lock and regenerated the name fields (npm install + npm ci --dry-run verified). npm keeps node_modules/capnweb → root as a workspace self-link, so capnweb-validate's capnweb dev/peer-dependency still resolves to this tree. Small cosmetic diff (dropped libc metadata fields) from local npm version differences.

Verification

On the final tree (macOS, local):

• npm run build — root + capnweb-validate build clean.
• npm test (vitest: node, workerd, Chromium, Firefox, WebKit) — 1216/1217 pass.
• npm run test:bun — 16/16 pass.
• npm run test:types — clean.

The one failure is WritableStream over RPC > applies backpressure when window fills up timing out on WebKit only, only under full-suite parallel load — it passes standalone (3/3 runs). This is an upstream flake, not introduced by the rebase: it reproduces identically on a pristine upstream/main (bc4bc45) worktree on the same machine (1 green run, then the same WebKit timeout). Upstream's Linux CI container presumably has different timing.

Additional review performed after the rebase: verified all five upstream correctness fixes (cloudflare#190) touch regions the fork doesn't modify and survive intact; verified RpcLimits depth accounting covers the WebSocket tunnel deserialization path; verified the onCall threading sites match the original fork design; fixed a stale changeset/README references to 0.8.x.

🤖 Generated with Claude Code

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Note

Medium Risk
Touches core RPC serialization, session handling, and capability lifecycle (including new WebSocket tunneling), so wire compatibility and resource-limit behavior matter; risk is mitigated by broad new tests and upstream security fixes, but integration is a full rebase intended for force-push to main.

Overview
Rebases the iterate fork onto upstream capnweb v0.10.0, dropping the unused fallbackCall work and replaying fork-only RPC and release changes on the new base.

Upstream behavior now in the tree includes capnweb-validate, receiver-side RpcLimits, custom transport encoding levels, ArrayBuffer/typed-array wire support, broader stream chunk typing, stream stub lifecycle fixes, and hardened error/abort/WebSocket-close handling — with large test additions (limits.test.ts, session-battery, transport encoding cases, deserialization regressions).

Fork deltas add WebSocket upgrade Response tunneling over RPC, RpcSessionOptions.onCall for server-side per-call observability (including pipelined calls), and publishing as @iterate-com/capnweb with README/install guidance, changesets pointed at iterate/capnweb, tag-driven npm release (replacing Changesets-driven Cloudflare release), pkg.pr.new previews on main/PRs, and removal of Cloudflare-only CLA/Bonk CI. Tooling/docs shift CI to Node 24, refresh the worker-react example around @validateRpc() / validateStub(), and add Bonk agent/reviewer config for this repo.

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CI status on this PR — read this before judging the checks

• CLAssistant: fail is expected and comes from the base branch. cla.yml is a pull_request_target workflow, so it runs from the current main — which still has Cloudflare's CLA assistant. This PR deletes it; the check disappears once main is updated to this branch. (This failure is itself a live demo of why the fork removes these workflows.)
• The Test workflow can't run as a PR check here — GitHub skips pull_request workflows when it can't create a merge ref, and this PR is intentionally unmergeable (history rewrite). Instead, test.yml gained a workflow_dispatch trigger and was run manually against rebase-0.10; see the Actions tab for the run on this branch (full suite: vitest across Node/workerd/Chromium/Firefox/WebKit, Bun tests, type tests).

[github-actions]

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I have read the CLA Document and I hereby sign the CLA

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4 out of 9 committers have signed the CLA.
✅ (teamchong)[https://github.com/teamchong]
✅ (dimitropoulos)[https://github.com/dimitropoulos]
✅ (ndisidore)[https://github.com/ndisidore]
✅ (codehz)[https://github.com/codehz]
❌ @SamJB123
❌ @aleister1102
❌ @taylorodell
❌ @ttmx
❌ @jonastemplestein
_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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[cursor]

OIDC publish blocked by token env

Medium Severity

The release job sets registry-url on setup-node and always exports NODE_AUTH_TOKEN from secrets.NPM_TOKEN. When trusted publishing is configured and no NPM_TOKEN secret exists, that empty token often prevents npm from using OIDC, so npm publish --provenance fails despite the workflow comment preferring OIDC.

 

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[cursor]

Release gate runs flaky suite

Medium Severity

Tag-triggered releases now run the full npm test suite before publish. The PR notes a WebKit-only, parallel-load timeout in an upstream writable-stream test that can fail intermittently on the same tree, so release workflows may abort without publishing even when the artifact is otherwise validated.

 

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[jonastemplestein]

Integrated by force-pushing this branch over main (history rewrite, as described above) — main is now upstream v0.10.0 + the 6 fork commits. GitHub shows the PR as closed rather than merged because of the rewrite.