feat(mcp-gateway): MCP gateway extension with 4-point security scanning#148
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Bridge pi to a LiteLLM-proxy MCP endpoint via two meta-tools (mcp_list_tools, mcp_call) that speak MCP streamable-HTTP JSON-RPC. Every piece of gateway-supplied text is scanned with the vendored shared security layer. Security model: - 4 scan points: outbound args (hard-block on dangerous/secret-material), inbound content, tool descriptions, and tool names+schemas in listings. - TOFU manifest pinning; mcp_call blocked when a server's manifest changes until /mcp-gateway accept-changes. - LiteLLM key never appears in tool output, config, notify text, or errors; transport-error messages are scanned/omitted; cross-finding secret scrub (descending-length ordering) prevents key fragments leaking via any finding. - Inbound DoS guard: SCAN_INPUT_CAP short-circuits before the O(n^2) scanner on >64KB gateway content (includeRiskyContent cannot bypass). - set-gateway normalizes to origin (strips userinfo/path/query). Reviewed adversarially by pi/GLM-5.2 across 4 rounds (REJECT -> HOLD-1 -> HOLD-2 -> ACCEPT); frozen build spec + review trail in mcp-gateway/docs/. Shared scanner amendments synced to all 4 vendored copies; verify-shared-sync extended to cover mcp-gateway. All test suites green. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Jgj3pnB7jzAtbSN8gemuAC
lantiscooperdev
approved these changes
Jul 23, 2026
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Summary
Bridge pi to a LiteLLM-proxy MCP endpoint. Two meta-tools —
mcp_list_toolsandmcp_call— speak MCP streamable-HTTP JSON-RPC tohttps://<gateway>/mcp/<server>; every piece of gateway-supplied text is scanned with the vendored shared security layer.Security model (4 scan points)
dangerousrisk or anysecret-materialfinding (a single credential blocks;includeRiskyContentcannot bypass — it is inbound-only).includeRiskyContentopt-in.Plus: TOFU manifest pinning (mcp_call blocked on manifest change until
/mcp-gateway accept-changes); the LiteLLM key never appears in output/config/notify/errors; transport-error messages scanned/omitted; cross-finding secret scrub (descending-length ordering) so no key fragment leaks via any finding's match; inbound DoS guard (SCAN_INPUT_CAPshort-circuits before the O(n²) scanner on >64 KB content);set-gatewaynormalizes to origin.Review trail
Adversarially reviewed by pi/GLM-5.2 over 4 rounds: REJECT (1×P1 + 6×P3) → HOLD-1 (residual key-leak) → HOLD-2 (prefix-subset fragment + O(n²) DoS) → ACCEPT. Frozen build spec and full review trail committed under
mcp-gateway/docs/(PLAN.md,REVIEW_R4.md).Test plan
bash mcp-gateway/test-fixtures/run-mcp-gateway-tests.sh— mcp-client + security-gating suites greenbash scripts/verify-shared-sync.sh— all 4 vendoredsecurity-scan.tscopies in sync (now includes mcp-gateway)node scripts/test-security-scan.mjs— shared scanner tests green (incl. new secret-scrub + prefix-subset assertions)npx tsx -e "import('./mcp-gateway/lib/mcp-client.ts')"— client import OK🤖 Generated with Claude Code