resent-one

Email and SMS for developers and enterprise SaaS. Send campaigns and transactional mail, automate journeys, and track delivery from one workspace. Start free with Resent. Resent email API with REST, SMTP relay, SDKs, and signed webhooks. Idempotent sends, delivery events, and 300 free emails a day. Start free—no card.

resent-one is listed with 1 API on the APIs.io network. Tagged areas include Company, Email, SMS, Messaging, and SaaS.

resent-one’s developer surface includes engineering blog, documentation, pricing, signup flow, support, changelog, and 12 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

32.3/100 thin Agent 27/100 agent aware Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

1 API

Company Email SMS MessagingSaaS

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 32.3/100 · thin

Contract Quality 0.0 / 21

Developer Ergonomics 4.5 / 17

Access Clarity 12.4 / 17

Operational Transparency 3.5 / 11

Contract Governance 0.0 / 10

Discoverability 5.8 / 9

Regulatory Posture 4.6 / 15

Agent readiness — 27/100 · agent aware

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

Regulatory Posture applies to this provider. Its tags matched the Telecommunications regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link

6 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Developer Ergonomics scores 26.2 — up to +14.8 composite points
Contract Governance scores 0.0 — up to +12.0 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/resent-one/apis.yml: open an issue on github.com/api-evangelist/resent-one to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

Resent Email API

Resent email API with REST, SMTP relay, SDKs, and signed webhooks. Idempotent sends, delivery events, and 300 free emails a day.

Pricing Plans 1

Published pricing tiers and plan structures.

Resent One Plans Pricing

5 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Resent One Rate Limits

0 limits

RATE LIMITS

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Resent One Authentication

0 schemes

SECURITY

Resent One Domain Security

TLSv1.3 · DMARC

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Resent One Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

SignUp

SignUp

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

Support

Support

StatusPage

StatusPage

ChangeLog

ChangeLog

Commercial 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 3

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Leadership

Leadership

Source (apis.yml)

aid: resent-one
name: resent-one
description: Email and SMS for developers and enterprise SaaS. Send campaigns and transactional mail, automate journeys, and
  track delivery from one workspace. Start free with Resent. Resent email API with REST, SMTP relay, SDKs, and signed webhooks.
  Idempotent sends, delivery events, and 300 free emails a day. Start free—no card.
url: https://artifacts.apis.io/resent-one/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-31 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-31'
modified: '2026-10-31'
image: https://resent.one/api/branding/logo?v=1784710648835
tags:
- Company
- Email
- SMS
- Messaging
- SaaS
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Plans
  url: plans/resent-one-plans-pricing.yml
- type: LLMsTxt
  url: llms/resent-one-llms.txt
- type: WellKnown
  url: well-known/resent-one-well-known.yml
- type: Hosts
  url: hosts/resent-one-hosts.yml
- type: Vendors
  url: vendors/resent-one-vendors.yml
- type: Leadership
  url: https://resent.one/company/leadership/
- type: DomainSecurity
  url: security/resent-one-domain-security.yml
- type: Website
  url: https://resent.one/
- type: Blog
  url: https://resent.one/blog/
- type: DeveloperPortal
  url: https://resent.one/features/email-api/
- type: Documentation
  url: https://resent.one/features/email-api/
- type: Pricing
  url: https://resent.one/pricing/
- type: SignUp
  url: https://resent.one/account/register/
- type: TermsOfService
  url: https://resent.one/legal-notice/
- type: PrivacyPolicy
  url: https://resent.one/legal/privacypolicy/
- type: Support
  url: https://resent.one/contact/
- type: StatusPage
  url: https://resent.one/contact/
- type: ChangeLog
  url: https://resent.one/releases/
apis:
- aid: resent-one:email-api
  name: Resent Email API
  description: Resent email API with REST, SMTP relay, SDKs, and signed webhooks. Idempotent sends, delivery events, and 300
    free emails a day.
  humanURL: https://resent.one/features/email-api/
  baseURL: https://api.resent.one
  tags:
  - Email
  - SMS
  - Transactional
  properties: []
x-coverage:
  state: unreadable
  reason: no-machine-readable-spec
  detail: No public OpenAPI or other machine-readable spec found despite API documentation page.
  evidence:
  - url: https://api.resent.one/openapi.json
    status: 200
  checked: '2026-10-31'
x-enrichment:
  date: '2026-10-31'
  status: enriched
  artifacts_added: 25
  pass: modular-v1
  engine: identity=oss,contract=oss,surfaces=oss,docs=oss,regulatory=oss

resent-one API — frequently asked questions

Does resent-one have an API?

Yes. APIs.io lists 1 API from resent-one, including Resent Email API.

How do I authenticate with the resent-one API?

resent-one documents its authentication (0 schemes). The details are profiled on APIs.io as Resent One Authentication.

How much does the resent-one API cost?

APIs.io lists 5 pricing plans for resent-one, with each plan's price, limits and inclusions under Pricing Plans on this page.

Is the resent-one API ready for AI agents?

resent-one has a Kin Score of 32.3 out of 100 (thin) and an Agent Readiness score of 27.2 (agent-aware), scored by API Evangelist on 2026-10-31.

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