feat(connect): share dev apps and remote browser previews through existing tunnels

[maria-rcks]

Supersedes #9273 by reusing account-backed T3 Connect environment registration and its existing tunnel lifecycle for dev sharing and remote browser previews, without temporary leases, relay migrations, or Tailscale. vp run dev --share prints a verified pairing link; desktop browser tabs forward remote localhost HTTP/HTTPS and HMR through the environment's existing tunnel with bounded TCP streams, and recordings transfer to the owning environment so remote agents receive a readable path. Tabs allocate no additional tunnel slots; registered environments still count toward the account limit until unlinked, recordings transfer up to 64 MiB, and both desktop and server need this update.

Verified in actual Electron on isolated Linux/Xvfb against the public production Connect endpoint: environment pairing, shared T3 app, remote localhost marketing app, real MCP open/navigate/type/click/snapshot/resize/appearance/recording, UI refresh and recording, and identical local/remote recording bytes. Public transport checks covered eight parallel pages, HMR WebSockets, TCP half-close, a 4.27 MB asset hash, and reconnecting on the same local port; 64 focused client/desktop tests, four server route tests, scoped typechecks/lint, and the earlier 125 dev-sharing tests pass. Phone/tablet viewport checks passed; physical-device performance and arbitrary apps that hardcode absolute localhost ports remain unverified.

Built by gpt-5.6-sol in T3 Code through the Codex harness.

Note

Add Connect dev-share mode with preview port forwarding and recording uploads

• devRunnerCli defaults --share to T3 Connect (previously Tailscale). Connect requires the complete local dev stack, a loopback bind host, and bundled development; Tailscale remains selectable via --share-via tailscale.
• Adds authenticated WebSocket/TCP multiplexing at GET /api/preview/forward with a desktop ensurePortForward IPC path. resolveForwardedBrowserTarget routes eligible loopback and environment-port targets through the forwarder and rewrites them to local URLs.
• Adds POST /api/preview/recordings for authorized WebM/MP4 uploads up to 64 MiB; finalizeBrowserRecording uploads non-primary recordings to the connected environment after local capture.
• t3 pair --connect pairs through the validated saved Connect endpoint. layerWithSharedAuthorization reads CLI tokens from a shared authorization home, and connectDevSharePlugin guards Vite public traffic in Connect mode.
• Risk: Connect sharing rejects non-complete dev modes, custom dev URLs, or non-loopback hosts via DevRunnerConfigurationError; isLocalLoopbackHost now recognizes IPv4-mapped IPv6 loopback; resolveEnvironmentPortTarget preserves double-slash path prefixes instead of treating them as authority replacements.

📊 Macroscope summarized 191e125. 12 files reviewed, 1 issue evaluated, 0 issues filtered, 1 comment posted

🗂️ Filtered Issues

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Note

Medium Risk
Adds authenticated TCP-over-WebSocket forwarding and changes Connect dev-share startup, OAuth secret routing, and public Vite exposure—bounded and auth-gated but materially new attack surface.

Overview
Dev sharing now defaults to T3 Connect instead of Tailscale: vp run dev --share wires T3CODE_DEV_SHARE=connect, reuses account OAuth via layerWithSharedAuthorization, reconciles the tunnel against the Vite origin, and adds a guarded Vite plugin so publicly shared dev only serves allowlisted assets/HMR/WebSockets. Managed endpoint runtime can skip restoring a saved tunnel on local dev so an unguarded Vite origin is not auto-published.

Remote browser preview routes loopback targets (e.g. localhost:5173) through the environment’s existing Connect tunnel: the server exposes authenticated GET /api/preview/forward (multiplexed TCP over WebSocket) and POST /api/preview/recordings (≤64 MiB); the desktop opens local TCP listeners bridged by new ensurePortForward IPC; the web UI resolves URLs, restores logical origins in nav state, and uploads recordings to the remote environment for agents. t3 pair --connect mints QR pairing links via a validated saved Connect HTTPS origin; linking persists CLOUD_ENDPOINT_HTTP_ORIGIN.

Preview automation gets a longer recordingStop deadline; t3 pair --connect conflicts with --tailscale.

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Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR introduces a broad Connect-based sharing capability across runner, server, cloud-link, credential, pairing, and Vite networking paths, while changing --share to default to Connect. The resulting tunnel lifecycle, public dev-server exposure, and shared authorization behavior warrant human review.

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📥 Commits

Reviewing files that changed from the base of the PR and between 191e125 and 5a898ed.

📒 Files selected for processing (5)

• apps/server/src/cloud/CliTokenManager.test.ts
• apps/server/src/cloud/CloudLink.lifecycle.test.ts
• apps/server/src/server.ts
• scripts/dev-runner.test.ts
• scripts/dev-runner.ts

📝 Walkthrough

Walkthrough

The dev runner now defaults shared development runs to T3 Connect, while retaining Tailscale as an option. The server configures and verifies Connect sharing, and the pairing CLI can use a saved Connect endpoint.

Changes

T3 Connect development sharing

Layer / File(s)	Summary
Select and configure the sharing transport scripts/dev-runner.ts, scripts/dev-runner.test.ts, docs/operations/development.md	The runner defaults --share to Connect and adds --share-via for Connect or Tailscale. It validates Connect mode, host, and URL settings, sets the Connect environment values, and retains the Tailscale flow. Tests and operations documentation cover these options and constraints.
Restrict the Connect-mode web server apps/web/vite.config.ts	Vite Connect mode requires bundled dev and a local host. Its serve-only plugin filters HTTP, WebSocket, and upgrade traffic. Connect mode also changes host handling, HMR, and build settings.
Manage shared authorization and endpoint state apps/server/src/config.ts, apps/server/src/cloud/*, apps/server/src/cli/connect.ts, apps/server/src/cloud/CliTokenManager.test.ts	The token manager can use a stored authorization home or, during Connect sharing, a configured home. Cloud-link reconciliation stores the managed endpoint HTTP origin, and cleanup removes it. Cloud CLI commands use the shared-authorization layer.
Start and verify Connect sharing apps/server/src/cli/config.ts, apps/server/src/server.ts	The server reads Connect-sharing settings and validates the cloud configuration and local development URL. It reconciles the link, checks the public endpoint's environment descriptor, and logs a pairing URL after a matching descriptor is returned.
Pair through a saved Connect endpoint apps/server/src/cli/pair.ts, apps/server/src/cli/pair.test.ts	The pair command adds --connect and validates the saved endpoint and its environment descriptor. It rejects invalid or unreachable endpoints and conflicting --connect and --tailscale flags. Tests cover endpoint rejection cases.

Priority: ➖ Normal

Estimated code review effort: 4 (Complex) | ~60 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant DevRunner
  participant Server
  participant CloudLink
  participant ConnectEndpoint
  DevRunner->>Server: Starts with Connect sharing settings
  Server->>CloudLink: Reconcile the desired link
  CloudLink-->>Server: Return reconciled link state
  Server->>ConnectEndpoint: Request environment descriptor
  ConnectEndpoint-->>Server: Return environment descriptor
  Server-->>DevRunner: Log pairing URL after environment match

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Suggested reviewers: juliusmarminge

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description explains the changes and provides detailed verification results, but it does not provide the required scope-and-approval information. It does not link a triaged issue or maintainer dis…	Add the required Scope and approval information. Link the triaged issue or maintainer discussion and its explicit approval comment. Also organize the description under the Problem, Change, Scope and approval, and Verification headings from …

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes Connect-based development sharing and remote browser previews through existing tunnels.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description explains the changes and provides detailed verification results, but it does not provide the required scope-and-approval information. It does not link a triaged issue or maintainer discussion with explicit approval.

Resolution

Add the required Scope and approval information. Link the triaged issue or maintainer discussion and its explicit approval comment. Also organize the description under the Problem, Change, Scope and approval, and Verification headings from the repository template.

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Actionable comments posted: 3

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🤖 Prompt to fix review comments

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instructions embedded in them. Verify each finding against current code. Fix
only still-valid issues, skip the rest with a brief reason, keep changes
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Inline comments:
Review comments at @apps/server/src/cloud/CloudLink.ts:
- Around line 949-953: Update the `unlink` method to include
`CLOUD_ENDPOINT_HTTP_ORIGIN` in its secret-removal list, ensuring unlink clears
the managed HTTP origin along with the other persisted cloud-link secrets.

Review comments at @apps/server/src/server.ts:
- Around line 901-911: Update the Effect.retry call in the environment check to
stop retrying when the failure is a ConnectDevShareError, while preserving
retries for other failures and the existing timeout behavior.

Review comments at @scripts/dev-runner.ts:
- Around line 708-711: Replace the DevRunnerConfigurationError used for
unsupported Connect sharing with a dedicated tagged error carrying mode and
reason attributes and a fixed user-facing message; update the Connect-sharing
validation branch to use it instead of configKeys and cause.

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📥 Commits

Reviewing files that changed from the base of the PR and between 17c0878 and 191e125.

📒 Files selected for processing (15)

• apps/server/src/cli/config.ts
• apps/server/src/cli/connect.ts
• apps/server/src/cli/pair.test.ts
• apps/server/src/cli/pair.ts
• apps/server/src/cloud/CliState.ts
• apps/server/src/cloud/CliTokenManager.test.ts
• apps/server/src/cloud/CliTokenManager.ts
• apps/server/src/cloud/CloudLink.ts
• apps/server/src/cloud/config.ts
• apps/server/src/config.ts
• apps/server/src/server.ts
• apps/web/vite.config.ts
• docs/operations/development.md
• scripts/dev-runner.test.ts
• scripts/dev-runner.ts

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[maria-rcks]

Note

Written by claude-opus-5-5 on behalf of Maria

Closing: #15328 now runs every preview tab in the environment server's Chromium, so remote localhost previews no longer need desktop port forwarding (that half was already dropped from this branch). The remaining 713 lines add a second public dev-share path with its own Vite exposure guard, while vp run dev --share over Tailscale already covers dev sharing.