Context Firewall MCP Server

Shrink large MCP tool outputs by 60–95% before they reach your model's context window - and collapse 50+ tool definitions into 4. Real HTML/JSON, measured - see benchmarks. Works with any MCP client, any model. Anything still over your configured token budget after compression is hard-truncated to that budget, with the full original always retrievable via read_more.

People who work with context window, mcp proxy and token optimization and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-09-03 · ★ 2 · #430 OF 945 MAINTAINED OTHER · VERIFIED 2026-09-18

MIT · TypeScript servers · how we verify → /methodology

01 · Install Context Firewall

before you install - you'll need

Set GITHUB_PERSONAL_ACCESS_TOKEN before connecting.

Claude Code

claude mcp add alepha188838884-context-firewall -- npx -y context-firewall

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "alepha188838884-context-firewall": {
      "command": "npx",
      "args": [
        "-y",
        "context-firewall"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license MIT - declared in the repository

npm package context-firewall - unscoped; check the name against the project README before installing

registry namespace io.github.Alepha188838884 is GitHub-verified and matches the repo owner

03 · What Context Firewall can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v0.4.0 · 2026-09-03

What's new · Main-content extraction before HTML→Markdown conversion: when a page has a recognizable content region (<article>/<main>), page chrome (nav, site headers/footers, hidden elements) is stripped first - so…

v0.3.0 · 2026-08-03

Untrusted-content framing for search_tools + startup digest (#2) · Second release motivated by community review on the MCP Discord. · search_tools results now arrive wrapped in <untrusted-tool-descriptions nonce="...">…

v0.2.0 · 2026-08-03

Per-server / per-tool allow & deny policy (#1) · From community review on the MCP Discord - collapsing N tools into 4 meta-tools shouldn't collapse your approval granularity. · allowTools / denyTools per downstream in…

04 · Who maintains Context Firewall

context-firewall is maintained by alepha188838884. It's the only MCP server we track from this author; the repo dates to Jul 2026.

05 · Facts

category
other - ranked #430 of 945 actively-maintained other servers as of 2026-09-18.
release cadence
4 releases in the last 90 days (latest 2026-09-03)
registry
io.github.Alepha188838884/context-firewall (active, first published 2026-07-28)
packages
npm:context-firewall

06 · Context Firewall FAQ

What is Context Firewall?

Shrink large MCP tool outputs by 60–95% before they reach your model's context window - and collapse 50+ tool definitions into 4. Real HTML/JSON, measured - see benchmarks. Works with any MCP client, any model. Anything still over your configured token budget after compression is hard-truncated to that budget, with the full original always retrievable via read_more.

Is Context Firewall still maintained?

Yes - as of 2026-09-18, its last commit was 2026-09-03 and it shipped 4 releases in the last 90 days. We re-verify nightly.

How do I install Context Firewall?

Run `npx -y context-firewall`. The README documents one environment variable (GITHUB_PERSONAL_ACCESS_TOKEN) to set first. Set GITHUB_PERSONAL_ACCESS_TOKEN before connecting. You can also paste the ready-made client config above.

Does Context Firewall run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Context Firewall