Show HN: Scan your AI agents for dangerous capabilities

Deny-by-default enforcement, human approvals, and a cryptographically signed audit trail

So your agent runs only what it's granted and provably can't approve its own work. Your agents keep running in their existing framework (LangChain, Claude SDK, CrewAI). MakerChecker sits in front of every tool call as a checkpoint and behind it as a signed ledger: an agent acts only through a role, runs only the skills it was granted, cannot exceed its limits, and cannot approve its own work.

Scan your agent for dangerous capabilities

Find what your agent can already do on its own, classified by risk. No install, nothing leaves your machine:

npx @makerchecker/scan .

It flags every consequential action - deleting data, moving money, running shell commands, exfiltrating secrets - names each against the real incident it resembles, and can write the governance code for you with --fix.

→ packages/scan

Embed governance in your code

Import the controls and wrap any tool. The agent can now only run what its role was granted - a call it isn't allowed is denied before it executes:

npm i @makerchecker/embedded

import { createGovernor, GovernanceDeniedError } from "@makerchecker/embedded";

const gov = createGovernor()
  .defineSkill("place-order@1", { riskTier: "high" })
  .defineRole("agent")
  .defineRole("risk-desk")
  .grant("risk-desk", "place-order@1")
  // the agent is NOT granted it - deny by default
  .defineAgent("trader", "agent");

// Wrap your tool once. Now the agent structurally can't fire it.
const placeOrder = gov.governedTool("trader", "place-order@1",
  (order) => broker.submit(order)
);

try {
  await placeOrder({ symbol: "BTC", qty: 10 });
} catch (err) {
  if (err instanceof GovernanceDeniedError)
    console.log(err.code); // "skill_not_granted"
}

High-risk skills go to a separate role, so an agent can never approve its own work - and every decision, allowed or denied, commits to a signed audit log.

→ packages/embedded

Self-hosted server with audit trail

Step 2 already writes a signed log. When auditors need a durable, queryable, tamper-evident record - plus a human-approval inbox and a review console - run the self-hosted server:

docker compose up

Every decision is Ed25519-signed and hash-chained: change any row and verification breaks. Export a bundle and anyone verifies it offline - no database, no trust in the process that produced it.

→ full server setup below

Three independent packages

These are three independent packages - mc scan, @makerchecker/embedded, and the server - that enforce the same controls and write the same signed audit format. Adopt any one on its own.

Runnable examples

Runnable examples of agents doing consequential work behind a human gate:

• Pharmacovigilance case processing - an agent triages adverse-event reports, but a medical reviewer signs before an expedited 15-day regulatory report transmits. examples/pv-icsr-processing
• Medical-device (MDR) complaint triage - a regulatory officer decides reportability behind a gate before draft reports are generated. examples/mdr-reportability-triage
• Oncology patient access - an agent handles benefit matching but is blocked from submitting copay enrollments without a specialist signing. examples/oncology-patient-access
• Daily cash reconciliation - a finance agent reconciles transactions but locks at exception gates until a cash officer signs off. examples/daily-cash-reconciliation

Drop-in connectors

Drop-in connectors govern the tools you already have:

• LangChain → packages/connector-langchain
• Claude Agent SDK → packages/connector-claude-agent
• TypeScript / Python SDKs → packages/sdk · packages/sdk-python

When you run the server, the SDK's governedTool routes each call through a proxy session for centralized authorization and recording:

import { createClient, governedTool, GovernanceDeniedError } from "@makerchecker/sdk";

const client = createClient({
  baseUrl: "http://localhost:3000",
  apiKey: "mk_..."
});

const { session } = await client.proxy.openSession({ label: "recon-run" });

const match = governedTool(
  client,
  session.id,
  "recon-preparer", // agent whose role grants are evaluated
  "txn-match@1",    // skillRef: name@version
  (input) => matchTxns(input),
);

await match({ statement, ledger }); // throws GovernanceDeniedError if denied
await client.proxy.closeSession(session.id);

Full gateway with approval inbox

Run the full gateway when you need centralized enforcement across many agents, a human-approval inbox, and a review console. docker compose up brings up Postgres, the server on localhost:3000, and a seeded demo, printing two API keys - an admin key (your agent authenticates runs) and an officer key (a human reviewer approves gated actions).

The seeded pharmacovigilance flow parks at a medical-review gate where the requester is refused as its own approver:

export H='authorization: Bearer mk_...'       # admin key
export OFFICER='authorization: Bearer mk_...' # officer key

curl -X POST localhost:3000/api/flows/pv-icsr-processing/runs \
  -H "$H" -H 'content-type: application/json' -d '{}'

curl localhost:3000/api/approvals -H "$H"

# The requester cannot approve their own run - rejected with 403
curl -X POST localhost:3000/api/approvals/<id>/decision \
  -H "$H" -H 'content-type: application/json' \
  -d '{"decision":"approved","reason":"self-approval attempt"}'

# A separate officer signs; only now does the action proceed
curl -X POST localhost:3000/api/approvals/<id>/decision \
  -H "$OFFICER" -H 'content-type: application/json' \
  -d '{"decision":"approved","reason":"Seriousness confirmed; file 15-day expedited ICSRs."}'

curl localhost:3000/api/audit/verify -H "$H"

Full setup, Kubernetes/Helm, and running with live models: docs/quickstart.md.

Tamper-evident audit log

Every decision and tool call commits to a hash-chained log - each event a SHA-256 over the RFC 8785 canonical JSON of the event, chained through prev_hash from genesis and Ed25519-signed. Change any row and verification breaks. Anyone can verify an exported bundle offline - no database, and no trust in the process that produced it:

npx @makerchecker/proof-verifier verify bundle.json

Spec: docs/audit-spec.md.

Package overview

Licensing

• Server, Web, Shared: AGPL-3.0. mc scan, embedded, SDKs, connectors, examples: Apache-2.0 - embed them in closed-source agents freely.
• Commercial (non-copyleft) licensing: hello@makerchecker.ai.

Contributing: CONTRIBUTING.md · Security: SECURITY.md · Code of Conduct: CODE_OF_CONDUCT.md