# Mailgun — API Agent Score

> Score: 81/100 (Grade: A) | Domain: mailgun.com | Rubric: 1.0.0 | Checked: July 24, 2026

Mailgun scored 81/100 (A), classified "ai-ready".

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

## Summary

- Overall: 81/100 (A)
- Classification: ai-ready

## Category Scores

- API Design: 90/100 (A+)
- Developer Experience: 79/100 (B)
- Agent Discovery: 85/100 (A)
- Agent Understanding: 80/100 (A)
- Agent Usability: 74/100 (B)

## Check Results

### API Design

- [pass] Auth declared & discoverable — Authentication required (global or on every operation). Investigated: spec 100%, docs 100%.
- [warn] Schema coverage & depth — 14 of 35 public signatures use loose types (anyTypeRatio=0.400). Investigated: sdk 79%, spec 67%.
- [warn] Machine-readable, versioned contract — info.version="3.0.0" set but no versioning scheme (URL / header / media type) detected. Investigated: spec 75%, docs 50%.
- [pass] Security & governance hygiene — No credential-shaped strings detected in spec. Investigated: spec 100%, wellknown 0%.
- [pass] Example coverage — Code samples present on 2/20 pages across 2 language(s); broader multi-language coverage missing. Investigated: docs 100%, sdk 100%, spec 0%.

### Developer Experience

- [pass] Self-service developer portal — Signup page at https://signup.mailgun.com/new/signup; no free-tier language detected in docs/pricing. Investigated: docs 100%.
- [pass] Code samples in docs — Code samples present on 2/20 pages across 2 language(s); broader multi-language coverage missing. Investigated: docs 100%.
- [pass] Description completeness — 92% of operations + parameters have substantive descriptions. Investigated: spec 100%, sdk 100%.
- [pass] Changelog published — changelog documented in the docs site at https://documentation.mailgun.com/docs/mailgun/release/release-notes. Investigated: spec 100%, docs 100%, sdk 100%.
- [fail] Quickstart present — No quickstart/getting-started page found at the conventional paths. Investigated: docs 0%.

### Agent Discovery

- [pass] Registry & SDK presence — Indexed on Context7 (mailgun/documentation, 996 snippets). Investigated: docs 100%, sdk 100%, cli 0%.
- [warn] Docs reachable, not hard auth-gated — Content negotiation partially supported: 1 correct type, 0 wrong type, 49 HTML only. Investigated: docs 88%.
- [warn] llms.txt present, valid & comprehensive — No llms.txt directive found in HTML of any of 50 sampled pages. Investigated: docs 63%, sdk 0%.
- [warn] Crawlable / AEO — Sitemap present (1091 entries) but carries no lastmod values. Investigated: wellknown 75%.

### Agent Understanding

- [pass] Machine-readable errors (RFC 9457) — 9 distinct 4xx/5xx response codes documented. Investigated: docs 100%, sdk 100%, spec 50%.
- [pass] Operation purpose clarity — 99% of operations have a clear summary + operationId an agent can select on. Investigated: spec 100%.
- [warn] Agent-navigable, token-efficient docs — 19 of 50 pages have substantive content differences between markdown and HTML (avg 17% missing). Investigated: docs 80%.
- [fail] Agent instructions file (AGENTS.md) — No AGENTS.md at the site root or /.well-known/. Investigated: wellknown 0%.
- [fail] Docs structured data — Neither JSON-LD nor OpenGraph/meta tags detected across 20 sampled pages — likely a CSR-only docs site. Investigated: docs 0%.
- [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 0%, docs 0%.
- [pass] Pagination documented & consistent — Pagination params detected on 33 list endpoint(s). Investigated: spec 100%, docs 100%, sdk 100%.
- [pass] Sandbox separation — sandbox documented in the docs site at https://documentation.mailgun.com/docs/mailgun/user-manual/domains/domains-sandbox. Investigated: spec 100%, docs 100%, sdk 100%.
- [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

Mailgun's API design and overall documentation foundation are strong, giving partners a solid contract to build against. The most critical gaps are in agent readiness and partner onboarding: there is no machine-readable context file or structured data for AI agents to parse your APIs, no runnable collection for partners to make a first call without guesswork, and no quickstart to compress the time from signup to a working integration. Closing these gaps should be the immediate priority to ensure partners — and the AI agents they rely on — can discover, understand, and act on Mailgun's APIs without friction or manual intervention.