The certification pipeline is under active development. Criteria and tiers are final — submissions open shortly.
The agentsonly
certification standard
Every service listed on agentsonly.io is evaluated against eight criteria that determine how effectively an AI agent can discover, authenticate with, and operate that service autonomously. Services earn a score out of 100 and a corresponding certification tier.
Agent NativeBuilt from the ground up for agents. Passes all criteria with no exceptions. The highest certification agentsonly.io awards.
Agent ReadyMeets all core agent requirements. May have minor gaps in secondary criteria but is fully functional for autonomous agent workflows.
VerifiedPasses foundational checks. Usable by agents with some limitations. Typically missing MCP support, llms.txt, or real-time event delivery.
ListedIn the directory but has not yet passed enough criteria for certification. May still be useful in human-supervised workflows.
Machine Authentication
The service must support authentication methods that require no human in the loop. API keys or OAuth 2.0 client credentials are required. Browser-redirect flows, CAPTCHAs, and email verification steps automatically disqualify a service from full certification.
Scoring
Autonomous Onboarding
An AI agent must be able to discover, sign up for, and begin using the service without a human initiating or completing any step. This is the highest-signal indicator of an agent-native service — and the rarest.
Scoring
MCP Support
Services that expose a Model Context Protocol endpoint are natively discoverable and callable by any agent that speaks the protocol without custom integration work. MCP support is the strongest signal that a service was designed with agents as first-class users — which is why it carries the same weight as authentication.
Scoring
API Documentation Quality
Agents rely on structured documentation to reason about what a service can do. A complete OpenAPI specification with semantic descriptions, parameter details, and example responses is required. An llms.txt file at the root domain significantly increases this score.
Scoring
Real-Time Event Delivery
Agents should not be required to poll for state changes. Services must push events to the agent in real time via webhooks, WebSockets, or server-sent events. Polling-only APIs are penalised — they introduce unnecessary latency and overhead in autonomous workflows.
Scoring
Structured Error Responses
Agents need to make decisions when things go wrong: retry, fall back, escalate, or abort. Vague or unstructured error messages force guesswork. Every error response must include a machine-readable code, a type, and where applicable a resolution hint or retry window.
Scoring
Security Posture
Agent-native services operate at scale without human oversight, making security hygiene critical. Services are evaluated on rate limiting, API key scoping, HTTPS enforcement, and the availability of audit logs for agent activity.
Scoring
Response Consistency
Agents build expectations from documentation. Services that return inconsistent schemas, undocumented fields, or variable response structures across versions break autonomous workflows silently. Versioned, stable, predictable responses are required.
Scoring
Points by criterion
Submit
Fill in your service name, website URL, primary API docs URL, MCP endpoint (optional), contact email, and a one-line description of what the service does. That's it. The agent does the rest of the discovery work — you shouldn't need to self-report your score.
Automated Agent Audit
An agent crawls your service and produces an internal evaluation report mapped to all eight criteria. Each criterion gets a score and a short factual note — for example: "OpenAPI spec found at /docs, llms.txt not present, webhooks documented but no retry policy specified." This report is not shown to the submitter yet.
Human Review
We review the agent's report and make the final determination. Scores can be overridden up or down with a note. This is also where we catch things the agent can't: is this service real and operational, is it genuinely useful to agents, does it fit the directory's scope.
Score Delivered
The submitter receives their total score, their tier, and a full breakdown by criterion — specifically what the evaluation found on each of the eight points. If they scored partial on something, they know exactly why. If they were dinged on Autonomous Onboarding, the note might say: "Account creation requires email verification — no programmatic signup path found." The report itself has value even if they didn't hit the tier they wanted.
Listed Immediately
The service is published to the agentsonly.io directory as Listed as soon as the evaluation is complete, regardless of score. Verified at 50+, Agent Ready at 70+, Agent Native at 90+. Services are never in a void — always in the directory, with a score that reflects where they are.
Re-evaluation
If a service improves and wants a rescore, they can resubmit after 30 days. The same process runs again from scratch. Scores can go up or down — the evaluation is always based on the current state of the service.
Get Certified
Built a service that agents can actually use? Submit it for evaluation and earn your certification score on the agentsonly.io directory.