webmcp-bridge

webmcp-bridge provides a local stdio MCP server that proxies MCP tool calls into a browser session running WebMCP. It prefers native WebMCP via the page’s `navigator.modelContext`, and falls back to injected adapter shims when native WebMCP isn’t available, using Playwright to drive the browser page.

Evaluated Mar 30, 2026 (0d ago)
Homepage ↗ Repo ↗ Automation mcp webmcp browser-automation playwright agent-tools stdio adapters
⚙ Agent Friendliness
54
/ 100
Can an agent use this?
🔒 Security
47
/ 100
Is it safe for agents?
⚡ Reliability
34
/ 100
Does it work consistently?

Score Breakdown

⚙ Agent Friendliness

MCP Quality
85
Documentation
80
Error Messages
0
Auth Simplicity
35
Rate Limits
20

🔒 Security

TLS Enforcement
60
Auth Strength
45
Scope Granularity
10
Dep. Hygiene
50
Secret Handling
70

Strengths: avoids credential vaulting/auth bypass by operating within an authenticated browser session; includes a user-facing use policy discouraging scraping/abuse. Risks/uncertainties: the bridge can automate user-authorized actions and run injected adapters; if misused, it could facilitate unauthorized automation. Details on TLS usage, dependency vulnerabilities, and structured error codes are not provided in the supplied content; scope granularity for tool authorization is not described.

⚡ Reliability

Uptime/SLA
0
Version Stability
40
Breaking Changes
50
Error Recovery
45
AF Security Reliability

Best When

You want a stable local MCP interface to browser-only WebMCP capabilities while keeping the authenticated browser context and optionally supporting headed collaboration.

Avoid When

You need a server-to-server API with strong built-in auth guarantees, or you require formal uptime/SLA and enterprise operational guarantees from the provider.

Use Cases

  • Connect a local MCP client to native WebMCP-capable websites in the same logged-in browser session
  • Use fallback WebMCP adapters on sites that don’t expose native WebMCP
  • Enable AI agents to collaborate with humans on the same browser/WebMCP surface (e.g., board demo)
  • Run integration/contract tests using deterministic fixture adapters

Not For

  • Unauthorized data collection or bulk scraping
  • Bypassing access controls, rate limits, or platform restrictions
  • Credential theft or moving credentials out of the browser session
  • Automating sites without user authorization or violating site terms

Interface

REST API
No
GraphQL
No
gRPC
No
MCP Server
Yes
SDK
No
Webhooks
No

Authentication

Methods: Browser session authentication (user already logged in)
OAuth: No Scopes: No

The README states the tool assumes users are already authenticated in the browser session; it also notes it does not implement credential vaulting or auth bypass.

Pricing

Free tier: No
Requires CC: No

No pricing information provided in the supplied README/repo metadata.

Agent Metadata

Pagination
none
Idempotent
False
Retry Guidance
Not documented

Known Gotchas

  • Requires Playwright installation and browser binaries (`npx playwright install`) before use.
  • Assumes authenticated browser session; if auth state is missing/expired, tool calls may fail until the user completes a headed sign-in.
  • Bridge-managed headless vs headed mode can differ after reattachment; if the site is sensitive to fingerprint/headed/headless switching, use separate profiles.
  • Session/profile reuse is important: `uxc` links intended to reuse the same daemon/session; running two modes concurrently may not be supported for all sites.
  • Adapter behavior depends on the target site and the adapter shim; failures may be adapter-specific rather than pure WebMCP failures.

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Scores are editorial opinions as of 2026-03-30.

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