Let Agents In

Agent readiness · Payments and billing

polar.sh

10 of 16 measurable points under formula 9.2, measured on 2026-08-12. 15 checks exist; each is one HTTP request with a published rule, so every sentence below can be rerun and argued with.

A · Discovery

  • PASS
    Answers an agent user-agentAnswered 200 to LetAgentsIn/1.0 (+https://letagentsin.com/methodology)
  • PASS
    llms.txt publishedllms.txt and llms-full.txt present at https://polar.sh/llms.txt and https://polar.sh/llms-full.txt, and the 12 links we sampled across both files all answer
  • PASS
    Docs readable without JavaScript10,767 characters of text without JS, on https://polar.sh/docs/api-reference/oauth2/request-token rather than on https://polar.sh/docs/introduction
  • PASS
    On-demand agents not blockedExplicitly allowed: ChatGPT-User, Perplexity-User
  • N/A
    Paths robots.txt points at answerrobots.txt names no concrete path, only patterns or nothing, so there is no claim to check
  • PASS
    No punishing crawl delayNo Crawl-delay applies to the agents we check

B · Agent entry

  • FAIL
    Agent entry pointNone of the 9 known agent entry paths returns a file rather than your page shell
  • PASS
    OAuth dynamic client registrationregistration_endpoint published, but none of the 3 advertised grants (authorization_code, web, refresh_token) finishes without a person at a browser
  • FAIL
    MCP surfaceMCP mentioned 3x in your own files, but nothing answered at mcp.polar.sh, mcp.polar.sh/mcp, mcp.polar.sh/v1/mcp, api.polar.sh/mcp, /mcp or /api/mcp

C · Registration

  • FAIL
    No CAPTCHA in the signup HTMLturnstile appears in the signup page's server HTML
  • PASS
    Signup reachable without a browserForm renders in server HTML at https://polar.sh/signup

D · Provisioning

  • FAIL
    Programmatic key provisioningNone of the 7 provisioning phrases appears in the 6 documents we read
  • PASS
    Free tier or no-card trial stated in textFree tier or no-card signals at https://polar.sh/resources/pricing: "Starter Free", "free Starter plan"

E · Integration

  • PASS
    Typed SDK on the registry@polar-sh/sdk@0.49.0 ships types, matched from the registry by who publishes it rather than by a link on your site
  • PASS
    Machine-readable API descriptionDocs serve markdown to machines, at https://polar.sh/docs/introduction

Tell me when this changes

The failures here are the kind nobody notices. An edge rule that starts refusing agents changes nothing a person sees in a browser, so the first sign is usually an integration that quietly stopped working. We rescan weekly and write only when a verdict moves.

This page is the newest scan we hold for polar.sh and changes when we rescan. It is not a judgement of the product: we measure whether an unattended run can get through, not whether the thing is any good. The whole corpus is published as JSON and CSV.

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