Web Debug MCP v0.4.0

Web Debug MCP 0.4.0

0.4.0 is a breaking contract release focused on trust boundaries, MCP-native output, and first-run reliability.

Highlights

• Fixes the selected top-level origin before navigation and rejects cross-origin redirects, actions, reloads, and popup-first documents in Chromium; Safari quarantines escaped WebDriver state.
• Adds schema-version-4 scenarios/results, MCP output schemas, canonical structuredContent, bounded progress, and opaque screenshot resources.
• Adds transactional resource handles, late-write cleanup, 4 MiB/file and four-file/16 MiB session screenshot quotas, explicit artifact retention/deletion, and destructive private session close.
• Adds press, exact select, declared check, hover, and scroll-into-view through the existing browser-action tool, with private fill/select replay and screenshot rules.
• Adds the bounded doctor CLI, full 13-tool in-memory routing coverage, source/test type checking, compatibility evidence, deterministic agent-evaluation grading, and process-group smoke teardown.

Breaking changes

• Scenario and verification schemas move to version 4; obsolete aliases and compatibility shapes are removed.
• Successful handler results use the canonical { ok, data, error, artifacts, warnings } structured envelope. MCP SDK input-validation failures remain protocol-level exceptions before handler dispatch.
• Closed sessions retain only a bounded sanitized tombstone. Fill/select inputs suppress screenshot pixels and are never restorable from public replay.

Verification

Verified locally with 106 deterministic tests, source/test typecheck, build, native and formal harness checks, plugin validation, final tarball/fresh-prefix stdio handshake, Chromium/React-Vite/Next/Safari/local-fidelity smokes, and the six-scenario comparison demo. This is local release evidence, not provider-backed production attestation.