# Circle — API Agent Score

> Score: 66/100 (Grade: C) | Domain: circle.com | Rubric: 1.0.0 | Checked: July 24, 2026

Circle scored 66/100 (C), classified "partially-ready".

[View full report](https://www.postman.com/ai/ai-ready-apis/company/circle)
[All organizations](https://www.postman.com/ai/ai-ready-apis/llms.txt)

## Summary

- Overall: 66/100 (C)
- Classification: partially-ready

## Category Scores

- API Design: 97/100 (A+)
- Developer Experience: 48/100 (F)
- Agent Discovery: 60/100 (C)
- Agent Understanding: 68/100 (C)
- Agent Usability: 62/100 (C)

## Check Results

### API Design

- [pass] Auth declared & discoverable — Authentication required (global or on every operation). Investigated: spec 100%, docs 100%.
- [warn] Schema coverage & depth — 17/17 (100%) public params are fully typed (no any/**kwargs). Analyzer confirms all methods have a derivable input schema. Investigated: sdk 99%, spec 76%.
- [warn] Machine-readable, versioned contract — info.version="1.0.0" set but no versioning scheme (URL / header / media type) detected. Investigated: spec 86%, docs 72%.
- [pass] Security & governance hygiene — No credential-shaped strings detected in spec. Investigated: spec 100%, wellknown 0%.
- [pass] Example coverage — 100% example coverage across params + responses. Investigated: spec 100%, sdk 100%.

### Developer Experience

- [pass] Description completeness — 44% description completeness. Investigated: spec 100%, sdk 100%.
- [fail] Self-service developer portal — No signup page detected across conventional paths (/signup, /sign-up, /register, /get-started, /console/signup, /dashboard/signup, /try, /try-free, /free, /free-trial, /start, /start-free). Investigated: docs 0%.
- [fail] Changelog published — No changelog URL or mention found in spec metadata. Investigated: spec 0%, docs 0%.
- [skip] Quickstart present — No surface produced evidence for this capability in this run.
- [skip] Code samples in docs — No surface produced evidence for this capability in this run.

### Agent Discovery

- [pass] Registry & SDK presence — Indexed on Context7 (rsta2/circle, 216 snippets). Investigated: docs 100%, wellknown 100%, sdk 92%, cli 0%, mcp 0%.
- [warn] Crawlable / AEO — Sitemap present (2432 entries) but carries no lastmod values. Investigated: wellknown 50%.
- [fail] llms.txt present, valid & comprehensive — No /llms-full.txt found at the candidate origins. Investigated: docs 0%, sdk 0%.
- [skip] Docs reachable, not hard auth-gated — No surface produced evidence for this capability in this run.

### Agent Understanding

- [warn] Operation purpose clarity — 86% of operations are agent-inferable (target 90%+). Investigated: spec 94%.
- [warn] Machine-readable errors (RFC 9457) — Single base error "null" present, but only 1 subclass found; a richer hierarchy lets consumers catch narrowly. Investigated: sdk 50%, spec 0%, docs 0%.
- [fail] Agent instructions file (AGENTS.md) — No AGENTS.md at the site root or /.well-known/. Investigated: wellknown 0%.
- [skip] Agent-navigable, token-efficient docs — No surface produced evidence for this capability in this run.
- [skip] Docs structured data — No surface produced evidence for this capability in this run.
- [skip] Description consistency across surfaces — Only 1 surface description(s) with ≥6 tokens available; need at least 2 to compare.

### Agent Usability

- [pass] Idempotency documented — Built-in retry machinery is present (grep-derived). Investigated: sdk 100%, spec 39%, docs 39%.
- [pass] Sandbox separation — Sandbox environments are exposed (sandbox). Investigated: sdk 100%, spec 0%, docs 0%.
- [warn] Runnable collection with test scripts — No test scripts found in the workspace's collections. Investigated: platform 50%.
- [fail] Rate-limit signaling — No rate-limit response headers documented. Investigated: spec 0%, docs 0%.
- [fail] Pagination documented & consistent — No pagination on list endpoints. Investigated: spec 0%, docs 0%.

## Executive Summary

Circle's API design is a genuine strength — the machine-readable contract and schema quality give partners and their agents a solid foundation to build against. The two areas that most threaten partner-program growth are developer experience and agent discoverability: there is no self-service portal, no published changelog, and no machine-readable discovery artifacts (llms.txt, AGENTS.md) that would let partners and AI agents find and understand the API without a sales conversation. Prioritizing a branded, always-in-sync documentation portal and filling the agent-readability gaps will unlock self-serve onboarding and make Circle's APIs accessible to the AI-powered tools partners already use.