Early Access — Free for founding teams

Secure your AI agents. Prove what they did.

estoppl intercepts every AI agent tool call, enforces guardrails, and produces a tamper-evident audit trail. Set up in 2 minutes. No credit card required.

Get Started Free Book a Demo

See it in action

Watch estoppl intercept Stripe MCP tool calls in Cursor, block a $50,000 invoice from the cloud dashboard, and log every action with a signed audit trail.

One platform to secure, monitor, and verify AI agent actions

AI agents call APIs, execute code, and move money. estoppl gives you control over what they can do — and proof of what they did.

Org-Wide Dashboard

Monitor every agent in real time. Event feeds, decision badges, request/response inspection, and compliance exports.

Custom Policy Rules

Block lists, allow lists, amount thresholds, rate limits, and custom conditional rules on any field. Per-agent overrides.

Human Review

High-risk tool calls pause until a human approves or denies. One-click approve/deny via email, Slack, webhook, or dashboard.

Cryptographic Audit Trail

Every tool call signed with Ed25519 and hash-chained. Tamper-evident. Download verifiable receipts and compliance exports.

Attestation Header

Every forwarded request carries an X-Estoppl-Attestation header. Upstream servers verify governance before processing.

Remote Kill Switch

Block a tool or shut down an agent from the dashboard. Every proxy picks up the change within 5 seconds.

estoppl dashboard showing tool call events with ALLOW, BLOCK, and HUMAN_REQUIRED decisions

How it works

estoppl sits between your AI agents and the tools they call. Every action is intercepted, evaluated against policy, signed, and synced to the cloud for org-wide visibility and verification.

Your Agents

Agent 1

Agent 2

Agent 3

estoppl proxy

Policy evaluation·Ed25519 signing·Attestation header

Allowed calls forwarded

MCP Server A

MCP Server B

MCP Server C

Blocked calls never reach upstream

Every event synced

estoppl Cloud

Dashboard

Alerting

Kill switch

WORM

Verification API

Read the full architecture →

Built for the teams deploying AI agents

Security Teams

“How do I prevent AI agents from exfiltrating data or calling unauthorized APIs?”

Custom policy rules block or require human approval for any tool call based on the tool name, arguments, or amount. Per-agent overrides let you lock down risky agents without affecting others.

Compliance Teams

“How do I prove to auditors what our AI agents did — and didn't do?”

Ed25519 signed, hash-chained audit trail. Download verifiable receipts per event or export the full trail. Offline verification via CLI. Built for SEC 17a-4 and EU AI Act Article 14.

Engineering Teams

“How do I add guardrails without changing code or slowing down development?”

Run estoppl wrap to auto-detect and wrap all your MCP servers. Zero code changes. Sub-millisecond overhead. Get Slack notifications when a tool call needs human approval.

Platform Teams

“How do I verify that agents calling our APIs are authorized?”

Every forwarded request carries an X-Estoppl-Attestation header. Your API checks it with one GET request — confirming the agent, user, and policy decision before processing.

Get started

estoppl CloudFree during Early Access

For teams

✓Dashboard with real-time event monitoring
✓Custom policy rules and human review
✓Kill switch — block any tool in seconds
✓Email and Slack notifications with one-click approve/deny
✓Compliance exports and verifiable receipts

Get Started Free

Open Source

For developers

Full proxy with guardrails, signed audit trail, and local dashboard. Apache 2.0. No account required.

npmnpm install -g estoppl

Homebrewbrew tap estoppl/tap && brew install estoppl

View on GitHub