# Polygon — API Agent Score

> Score: 71/100 (Grade: B) | Domain: polygon.io | Rubric: 1.0.0 | Checked: July 24, 2026

Polygon scored 71/100 (B), classified "partially-ready".

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

## Summary

- Overall: 71/100 (B)
- Classification: partially-ready

## Category Scores

- API Design: 87/100 (A)
- Developer Experience: 81/100 (A)
- Agent Discovery: 92/100 (A+)
- Agent Understanding: 58/100 (D)
- Agent Usability: 51/100 (D)

## Check Results

### API Design

- [pass] Auth declared & discoverable — Authentication required (global or on every operation). Investigated: spec 100%, docs 100%.
- [warn] Machine-readable, versioned contract — info.version="1.0.0" set but no versioning scheme (URL / header / media type) detected. Investigated: spec 75%, docs 50%.
- [warn] Schema coverage & depth — High parameter complexity (avg 13.5 params/op + nested params). Investigated: spec 67%, sdk 53%.
- [pass] Security & governance hygiene — No credential-shaped strings detected in spec. Investigated: spec 100%, wellknown 0%.
- [pass] Example coverage — README is present and includes a runnable quickstart. Investigated: sdk 100%, spec 0%.

### Developer Experience

- [pass] Self-service developer portal — Self-service signup at https://massive.com/dashboard/signup; no free tier or sandbox language detected. Investigated: docs 100%.
- [pass] Description completeness — 85% description completeness (target 90%+). Investigated: spec 100%, sdk 98%.
- [fail] Changelog published — No changelog URL or mention found in spec metadata. Investigated: spec 0%, docs 0%, sdk 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] llms.txt present, valid & comprehensive — llms-full.txt reachable at https://polygon.io/llms-full.txt. Investigated: docs 100%, sdk 0%.
- [pass] Registry & SDK presence — Indexed on Context7 (treythomascodes/polygon-client, 269 snippets). Investigated: docs 100%, cli 100%, sdk 67%.
- [warn] Crawlable / AEO — Sitemap present (350 entries) but carries no lastmod values. Investigated: wellknown 50%.
- [skip] Docs reachable, not hard auth-gated — No surface produced evidence for this capability in this run.

### Agent Understanding

- [pass] Machine-readable errors (RFC 9457) — Only 3 distinct 4xx/5xx codes documented (plus 3 "default" catch-all responses). Investigated: docs 100%, spec 50%.
- [fail] Operation purpose clarity — 56% of operations are agent-inferable. Investigated: spec 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 0 surface description(s) with ≥6 tokens available; need at least 2 to compare.

### Agent Usability

- [pass] Pagination documented & consistent — Pagination params detected on 82 list endpoint(s). Investigated: docs 100%, sdk 100%, spec 75%.
- [warn] Sandbox separation — No test-mode flag or sandbox environment is exposed. Investigated: sdk 50%.
- [fail] Idempotency documented — No built-in retry machinery was found; transient failures are not retried. Investigated: sdk 0%.
- [fail] Rate-limit signaling — No rate-limit response headers documented. Investigated: spec 0%, docs 0%.
- [fail] Runnable collection with test scripts — No public Postman workspace discovered for the org. Investigated: platform 0%.

## Executive Summary

Polygon's API program has strong discoverability and a solid machine-readable contract — partners and agents can find and parse the surface with confidence. The urgent gaps are in agent understanding and operational usability: AI agents have no instructions file or clear operation-level semantics to build against, runnable examples are absent, and rate-limit and idempotency behaviors are undocumented, all of which force partners to guess their way through integrations. Prioritize publishing the agent context layer and executable collection first, then layer in changelog and reliability documentation to complete a partner-ready program.