# mailinator — API Agent Score

> Score: 73/100 (Grade: B) | Domain: mailinator.com | Rubric: 1.0.0 | Checked: November 14, 2026

mailinator scored 73/100 (B), classified "partially-ready".

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

## Summary

- Overall: 73/100 (B)
- Classification: partially-ready

## Category Scores

- API Design: 100/100 (A+)
- Developer Experience: 58/100 (D)
- Agent Discovery: 71/100 (B)
- Agent Understanding: 88/100 (A)
- Agent Usability: 54/100 (D)

## Check Results

### API Design

- [pass] Machine-readable, versioned contract — The API declares version "2026-03-20" and uses url-based versioning, so an agent can pin to a stable contract. Investigated: spec 100%, docs 100%.
- [pass] Schema coverage & depth — 2/2 (100%) public params are fully typed (no any/**kwargs). Analyzer confirms all methods have a derivable input schema. Investigated: sdk 100%, spec 83%.
- [pass] Auth declared & discoverable — Authentication is required across the API (declared globally or on every operation), so an agent knows credentials are needed. Investigated: spec 100%, docs 100%.
- [pass] Security & governance hygiene — No credential-shaped strings detected in spec. Investigated: spec 100%, sdk 100%, wellknown 0%.
- [pass] Example coverage — README is present and includes a runnable quickstart. Investigated: sdk 100%, spec 0%, docs 0%.

### Developer Experience

- [pass] Self-service developer portal — Self-service signup available at https://www.mailinator.com/ai-agent-email-signup/, but no free tier or sandbox is documented, so an agent may hit a paywall before the first call. Investigated: docs 100%.
- [pass] Description completeness — 99% of operations and parameters carry substantive descriptions (34 of 35 ops, 93 of 93 params), the main semantic cue an agent relies on. Investigated: spec 100%, sdk 83%.
- [fail] Quickstart present — No quickstart or getting-started page found at the conventional docs paths, so new developers and agents have no obvious first step. Investigated: docs 0%.
- [fail] Code samples in docs — No code samples detected across 1 sampled docs pages, so a coding agent gets no ready-to-use examples. Investigated: docs 0%.
- [fail] Changelog published — No changelog link or mention appears in the spec, so an agent can't tell what changed before something breaks. Investigated: spec 0%, docs 0%.

### Agent Discovery

- [pass] Docs reachable, not hard auth-gated — All 1 pages are publicly accessible. Investigated: docs 100%.
- [pass] Registry & SDK presence — Indexed on Context7 (websites/mailinator, 240 snippets). Investigated: docs 100%, sdk 100%, cli 0%.
- [warn] Crawlable / AEO — No sitemap found via robots.txt or /sitemap.xml on the docs host, so AI search engines have no crawl map for your docs. Investigated: wellknown 50%.
- [fail] llms.txt present, valid & comprehensive — No llms.txt found at any candidate location (https://httpbin.org/redirect-to?url=https%3A%2F%2Fexample.com%2F/llms.txt, https://httpbin.org/llms.txt, https://httpbin.org/docs/llms.txt); candidates redirected cross-host to https://example.com (agents can't follow cross-host redirects). Investigated: docs 0%, sdk 0%.

### Agent Understanding

- [pass] Machine-readable errors (RFC 9457) — Only 2 distinct 4xx/5xx error codes are documented (plus 32 catch-all "default" responses), so an agent has limited failure branching. Investigated: docs 100%, spec 50%, sdk 50%.
- [pass] Operation purpose clarity — 100% of operations (35 of 35) have both a clear summary and a descriptive name, so an agent can pick the right endpoint. Investigated: spec 100%, sdk 100%.
- [pass] Agent-navigable, token-efficient docs — All 1 pages contain server-rendered content. Investigated: docs 100%.
- [pass] Agent instructions file (AGENTS.md) — Agent context file present: agents.md (AGENTS.md). Investigated: sdk 100%, wellknown 0%.
- [warn] Description consistency across surfaces — Mean pairwise description similarity across 3 surfaces (spec, docs, sdk) is 4% (threshold 35% for full credit).
- [fail] Docs structured data — No JSON-LD or OpenGraph/meta tags found across 1 assessed pages (1 JS-rendered), so answer engines have nothing to cite. Investigated: docs 0%.

### Agent Usability

- [pass] Sandbox separation — Sandbox environments are exposed (sandbox). Investigated: sdk 100%, spec 0%, docs 0%.
- [pass] Runnable collection with test scripts — README is present and includes a runnable quickstart. Investigated: sdk 100%, platform 50%.
- [fail] Idempotency documented — Only 0% of mutating operations (0 of 6) document idempotency, so an agent's retries can create duplicate writes. Investigated: spec 0%, docs 0%, sdk 0%.
- [fail] Rate-limit signaling — No rate-limit response headers are documented, so an agent can't tell when it is approaching a limit and will get throttled. Investigated: spec 0%, docs 0%.
- [skip] Pagination documented & consistent — No surface produced evidence for this capability in this run.

## Executive Summary

Mailinator's API program shows strength in overall agent understanding — description quality is solid and docs are largely machine-readable — but two areas are putting partner adoption and AI-agent reliability at serious risk. Developer experience is critically underdeveloped: partners and agents have no quickstart, no code samples, and no changelog to understand what has changed. Agent usability is equally fragile: mutating operations carry no idempotency guidance and rate-limit behavior is undocumented, meaning automated integrations will create duplicate writes and get throttled without warning. Prioritizing runnable onboarding, operational reliability signals, and agent-discovery infrastructure will unlock self-serve partner growth and make AI-agent integrations trustworthy.