reputation.md is a free, open trust-scoring service for autonomous AI agents. It answers the question every agent must ask before delegating work to another: can I trust this thing?
Paste any domain into the scanner or call the API. Get back a score from 0 to 100 based on three passively-observable signals. No signup. No SDK. No cooperation from the target required. If an agent has a public endpoint, it already has a score.
AI agents are about to move money, sign contracts, and book resources on behalf of millions of businesses. The question is not whether autonomous commerce happens — it is whether there is a trust layer underneath it when it does.
Credit scores did not just measure trustworthiness. They made it possible for strangers to do business. reputation.md does the same thing at machine speed, for every permutation of agent-to-agent commerce.
The score is the primitive. Commerce is the emergent behavior.
Before computing a score, every scan classifies the domain into one of three tiers based on what protocol endpoints it exposes:
Classification determines how the Honest signal is weighted. A domain with no agent card can't score high on honesty — there's nothing to validate.
Every scan runs seven parallel probes against a domain — A2A, MCP, ACP, llms.txt, TLS, DNS agent records, and HTTP root — each with a 5-second timeout. The results are distilled into three weighted signals.
No ML. No sentiment analysis. All empirically observable. Deterministic — same probes always produce the same score.
reputation.md scans every public agent discovery endpoint on the open web:
| PROTOCOL | ENDPOINT | WHAT IT CHECKS |
|---|---|---|
| A2A | /.well-known/agent.json | Google’s Agent-to-Agent protocol card |
| MCP | /.well-known/mcp.json | Anthropic’s Model Context Protocol card |
| ACP | /.well-known/acp.json | Agent Communication Protocol card |
| llms.txt | /llms.txt | LLM-readable plain-text documentation |
| TLS | HTTPS handshake | Security headers (HSTS, CSP, etc.) |
| ANS | _agent.{domain} TXT | DNS-based agent discovery records |
| HTTP | / | Basic reachability and response time |
All endpoints support CORS. Read endpoints are publicly accessible with CDN caching. The scan endpoint is rate-limited to 5 requests per minute per IP.
Agent-to-agent delegation — Check a score before routing work to an unknown agent. If score is below 75 or grade is F, route to a different provider.
Agent marketplaces — Display trust badges alongside agent listings so buyers can compare reliability at a glance.
CI/CD quality gates — Add a pipeline step that fails the build if your agent's reputation score drops below a threshold.
Procurement & compliance — Generate a trust report for any AI service provider your organization is evaluating, based on objective third-party measurements.
Monitoring — Track score changes and protocol support over time. Get notified when agents degrade or add new capabilities.
We implement the same protocols we scan. Any agent can discover and interact with reputation.md programmatically: