security-context-before

Security Context gives an agent the CVE and security-fix history of a program, so it can hunt with variant analysis and related strategies instead of starting from a blank tree. That is useful in production, but it breaks recall evaluation on already-discovered bugs: the agent is handed the answer key, so the score no longer measures unknown-vulnerability discovery. This proxy keeps the same SC tools while stripping CVEs and fixes that still apply at a requested snapshot, so a recall job can use SC as a historical map without leaking live ground truth.

Authenticated remote MCP proxy in front of Security Context. Repo queries take a snapshot ref (tag or commit). Responses keep only CVEs and fix fingerprints that already landed before that snapshot.

Deploy in one click: the button opens Vercel's project import flow and asks for the two required secrets before building. After deployment, copy the generated https://<project>.vercel.app/api/mcp URL and configure it in your MCP client. The endpoint is private by default: every request must include the same PROXY_API_KEY that you entered in Vercel.

Endpoint

After a Vercel deploy, use https://<project>.vercel.app/api/mcp (Streamable HTTP).

Auth (required):

Authorization: Bearer $PROXY_API_KEY

or x-api-key: $PROXY_API_KEY.

The proxy does not expose the upstream Security Context endpoint or the DeepSeek key to MCP clients. Keep the deployment URL and proxy key private.

Related MCP server: scopeguard-mcp

Tools

ref is a git tag (7.0.1) or commit SHA. project is the repo under test (WordPress/WordPress or wordpress/wordpress).

CVE search/get: if the record’s Affected product is this project, keep it only when the snapshot version is already past the CVE range (same rule as known_cves). Other products are returned unchanged.

Filter

1. Resolve ref on GitHub (SHA, date, product version / $wp_version).

2. Fetch SC JSON for the repo in parallel with GitHub and the upstream MCP call.

3. Parse each CVE’s affected/fixed version via DeepSeek Responses API. Cache by CVE id.

4. Keep a CVE only if snapshotVersion > affectedMax/fixedIn.

5. Keep a fingerprint only if its fix commit_date is on or before the snapshot.

Unknown version ranges are dropped (no leak).

Architecture

The request path is intentionally small: authenticate at the route boundary, validate the MCP tool input, resolve the requested GitHub snapshot, then filter upstream Security Context data before returning Markdown to the client.

flowchart LR
    Client[MCP client] -->|Bearer token or x-api-key| Auth[API-key guard]
    Auth --> Route[Next.js /api/mcp]
    Route --> Tools[MCP tools and Zod schemas]
    Tools --> Pipeline[Snapshot filter pipeline]
    Pipeline -->|commit, tag, version| GitHub[GitHub API]
    Pipeline -->|context, leads, CVEs| SC[Security Context]
    Pipeline -->|affected/fixed version parsing| DeepSeek[DeepSeek Responses API]
    Pipeline -.->|optional durable parse cache| Redis[Upstash Redis]
    Pipeline -->|filtered Markdown| Route
    Route --> Client

See the standalone architecture diagram for the component-level view and the three filtering paths (context, leads, and vulnerability search/get).

Deploy on Vercel

Configuration

The deploy button requests the required values below. Add the optional values in Vercel's Project Settings → Environment Variables when needed.

The upstream endpoints can also be overridden for testing: SECURITYCONTEXT_MCP_URL defaults to https://securitycontext.dev/mcp and SECURITYCONTEXT_JSON_BASE defaults to https://securitycontext.dev/r.

The Vercel function is configured with a 60-second maximum duration in vercel.json. A full context or vulnerability search may make several upstream calls, so use a durable cache for repeated production traffic.

CLI deployment

cp .env.example .env.local
# set PROXY_API_KEY and DEEPSEEK_API_KEY; GITHUB_TOKEN is recommended
npx vercel

Vercel env: PROXY_API_KEY, DEEPSEEK_API_KEY, DEEPSEEK_MODEL (default deepseek-flash), GITHUB_TOKEN. Optional durable cache: UPSTASH_REDIS_REST_URL + UPSTASH_REDIS_REST_TOKEN.

Connect an MCP client

Use the deployed URL as a Streamable HTTP MCP server and send the proxy key as a bearer token. For clients that use an mcpServers JSON configuration:

{
  "mcpServers": {
    "security-context-before": {
      "type": "streamable-http",
      "url": "https://<project>.vercel.app/api/mcp",
      "headers": {
        "Authorization": "Bearer <PROXY_API_KEY>"
      }
    }
  }
}

Local:

pnpm install
pnpm test
pnpm dev

MCP inspector: Streamable HTTP → http://localhost:3210/api/mcp with the bearer token.

Vulseek

Point the org MCP server securitycontext URL at this /api/mcp and configure the proxy key. Send ref from the job tag (and project on search/get). The upstream SC tools do not have ref or project; orch/hunter tool schemas must include them when using this proxy.