Resend API

https://resend.com · v1.5.0 · 83 operations · 154 schemas

Resend scores an F (27) — the lowest in this analysis. Most operations have no examples, no error documentation, weak operationIds, and very short descriptions. Pagination is the lone bright spot at 100. For a developer-focused email API, this is surprising — but Resend is also the youngest company on this list, and OpenAPI investment typically lags behind hand-written docs.

Category breakdown

Examples0

Semantics34

Intent29

Error Handling0

Parameters63

Pagination100

Key findings

All 83 operations and 154 schemas lack examples
78 of 83 operations have missing or very short descriptions
All 83 operations omit error response documentation
All 83 operations have missing or poor operationIds
148 of 154 schemas have no description

What Resend should fix

This spec needs a comprehensive overhaul. Prioritize: descriptions on all operations, examples for the most common ones (send email, create domain, create API key), and error responses everywhere.
Add real operationIds — `sendEmail` instead of whatever the spec currently generates.
Describe the 148 schemas currently lacking descriptions, especially the email object and domain configuration objects.
Document standard errors: rate limits, invalid sender, unverified domain. These are the failures agents will see most.

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