There are many agent gateways but this one never phones home.
Guarding your credentials and budget while letting your agents build.
MeterGate (v1.0.0) is a minimal, zero-telemetry, 100% offline AI Agent security firewall, official-rate cost ledger, and standard MCP (JSON-RPC 2.0) middleware. It intercepts lethal trifecta prompt injections and .env secret exfiltrations, records verifiable cost ledgers against official rates, and adapts to your workflow — not the other way around.
🔒 Zero Telemetry (0 Bytes Sent)📴 100% Offline (Zero CDN)👀 Observe-Only Onboarding (0% Breaking Risk)⚖️ MIT Open Source (No Paywalls)🧹 Clean Zero-Residual Uninstall
uvx metergate serve --mcp-stdio
$ scroll to continue · Zero-Git Unattended Launch: Direct standard MCP stdio pipe mounting.
Definition: MeterGate is a single-instance, 100% offline, zero-telemetry open-source AI Agent security gateway and cost ledger.
• Latency: <3ms local inspection overhead• Concurrency: ≤32 active requests (fast-fail HTTP 503)• Outbound Traffic: Exactly 0 bytes• License: MIT Open Source
01 / WHY METERGATE?
Change the gateway, not your agent workflow
Modern coding agents like Claude Code, Cursor, Windsurf, and OpenClaw run arbitrary tools and consume tokens rapidly. But without a local guardrail, two silent traps emerge: cost blindness (not knowing where tokens were burned) and secret exfiltration (indirect prompt injection reading local .env files and pushing them to external webhooks).
Design Tenet
MeterGate sits silently on 127.0.0.1:8787 or in a --mcp-stdio pipe. It does not phone home to a cloud server, does not require an enterprise login, and does not require complex rewrites of your prompt chains.
• Three-Tier Lightweight Firewall: Front-redacts keys, <3ms local heuristic scoring.
• Official Published Rates: Reconciled line-by-line against actual official provider pricing.
• Zero-Risk Onboarding: Runs in Observe-Only mode as a seamless sidecar.
First-Hand Token Ledger with Verifiable Cost Derivation
Cost estimation is secondary and prone to distortion from vendor price changes and tiered discounts; Token usage is the sole verifiable first-hand truth directly matching the API response usage field and vendor Dashboards. MeterGate promotes Token metering by Model ID × Direction (Prompt / Completion / Cached) to a first-class citizen, overlaying official public rates as derived secondary value with catalog freshness alerts. Start risk-free in Observe-Only mode (metergate serve --mode observe)!
Live Firewall Sandbox
📌 Status: Waiting for test execution...
👉 Tip: Click "Run 3-Tier Firewall Test" to evaluate redaction and interception.
Two-Tier Ledger: Primary Token Ledger & Official Rate Cost Derivation
Anchored to official published rates (USD / 1K tokens), with automated warnings if catalogs exceed 30 days of staleness:
Like pi.dev, MeterGate is aggressively minimal. Features other tools bake in are deliberately omitted to preserve your agency, performance, and complete local privacy.
No Cloud Telemetry
We don't collect prompts, bills, or metrics. There are zero background beacons or exfiltration endpoints. Everything lives in your local SQLite file.
No Multi-Tenant RBAC Bloat
MeterGate is explicitly designed as a single-instance local developer gateway (≤32 concurrent in-flight requests with fast-fail HTTP 503). No complex enterprise SSO or user tables.
No Heavy Neural Judge Latency
Tier 2 uses a sub-3ms heuristic concept cluster and N-gram scorer. It adds zero noticeable latency to your agent, while honestly disclosing its known blind spots.
No Commercial Paywalls
Pure MIT license. No feature locks, no 402 Payment Required traps, and no trial expiration timers.
No Forced Blocking
Use metergate serve --mode observe to start with 0% false-positive risk. Gather proof first, enforce when ready.
04 / PI.DEV HOMAGE
and it can play Trifecta Shield 🎮
An interactive terminal defense mini-game directly in your browser. Move your gateway shield to intercept leaking .env and sk-live packets while letting benign MCP requests pass.
Fig. 01 | TRIFECTA_DEFENDER_TERMINAL
Score: 0 | Intercepted: 0
Controls: Mouse move / Arrow keys [◀ ▶] control the shieldRed = .env leak | Cyan = sk-live key | Green = benign MCP
05 / ZERO-EXFIL TELEMETRY → THE SURPRISE CAPSULE
🎁 Local Zero-Exfil Sensing: Synthesize a Bespoke Surprise Kit
While other tools track you to sell ads, MeterGate's telemetry runs 100% in local memory (outbound traffic is strictly 0 Bytes). By observing your interactive preferences on this page, it synthesizes a bespoke 4-in-1 gift capsule directly on your machine:
Local Telemetry Pulse0 BYTES EXFIL
Inferring your developer persona...
Generated based on your selected install preference, pricing slider, and sandbox actions.