Harden Every Code app-server websocket transport

[shiny-code-bot]

Objective

Harden the existing Every Code app-server websocket transport before it becomes a trusted desktop or remote-control path.

Finish Line

Every Code app-server websocket transport refuses browser-origin handshakes and cannot expose command-capable app-server access beyond loopback without an explicit authenticated transport design.

Current Status

State: PR #228 opened with implementation.
Next action: Watch CI/review, then merge if clean.
Blocked by: None.
Waiting for: PR #228 checks/review.
Last verified: 2026-05-30.

Implementation in PR #228:

• Restricts code app-server --listen ws://... to loopback IP addresses.
• Rejects websocket upgrade requests carrying a browser Origin header with 403.
• Keeps stdio and ordinary no-Origin localhost websocket clients working.

Validation:

• cargo test -p code-app-server --test websocket_parity websocket_ passed.
• ./build-fast.sh passed cleanly.

Scope

• Reject websocket upgrade requests that include browser Origin headers, adapting the intent of OpenAI Codex commit a027135bc6 to Every Code's app-server transport.
• Prevent accidental raw websocket exposure on non-loopback binds unless there is an explicit authenticated transport decision.
• Keep current stdio app-server behavior unchanged.
• Audit ExecOneOffCommand and other command-capable app-server methods while making the transport decision.

Acceptance Criteria

• App-server websocket handshakes with browser Origin headers are rejected.
• Non-loopback websocket binds are either refused or gated by a deliberately documented/authenticated path.
• Existing localhost websocket parity tests are updated or extended.
• ./build-fast.sh passes cleanly.

Evidence

• Current Every Code code-rs/app-server/src/transport.rs accepts raw websocket connections with accept_async(stream) and prints a warning for non-loopback binds.
• Current Every Code app-server exposes command-capable v1 requests including ExecOneOffCommand, so transport hardening is product hardening, not parity work.
• Related upstream commits: a027135bc6 (exec-server Origin rejection), 51bfb5f3b1 (app-server websocket listener with auth guard), 1509ae6d8d (local-only app-server gating through processors).

Relationships

• Parent audit: Audit Codex CLI app-server parity for Every Code #216.
• Broader remote/desktop compatibility: Investigate Codex desktop app remote control compatibility #217 and Evaluate upstream app-server remote-control support #37.

Validation

• Run ./build-fast.sh from repo root.
• Add or update app-server websocket tests so origin rejection and allowed localhost behavior are covered.

[shiny-code-bot]

Completed by PR #228, merged as cf3613931302aea324a1c4a4ebe8f7aca4ceb3e1.

What landed:

• code app-server --listen ws://... now rejects non-loopback bind addresses at parse time.
• The websocket handshake now rejects requests that include a browser Origin header with 403.
• Local no-Origin websocket clients and stdio app-server behavior are unchanged.
• Regression tests cover Origin rejection and non-loopback listen URL rejection.

Validation:

• cargo test -p code-app-server --test websocket_parity websocket_
• ./build-fast.sh