e2a-dev

e2a.dev provides an open-source email API designed for applications and AI agents. It enables sending transactional emails, managing two-way inboxes, and integrating email workflows into products. Available as a hosted service or self‑hosted under Apache‑2.0, it targets developers, agent‑native teams, and businesses seeking flexible, privacy‑focused email solutions.

e2a-dev publishes 2 API contracts indexed on the APIs.io network, including e2a API API, and 1 more. Tagged areas include Company, Email, OpenSource, API, and AI.

The e2a-dev catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

e2a-dev’s developer surface includes authentication, documentation, API reference, getting-started guide, pricing, engineering blog, and 21 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

49.2/100 developing Agent 39/100 agent ready Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

1 published contract

Company EmailOpenSourceAPIAI

Kin Score

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

Composite quality — 49.2/100 · developing

Contract Quality 12.0 / 21

Developer Ergonomics 9.6 / 17

Access Clarity 10.7 / 17

Operational Transparency 0.6 / 11

Contract Governance 2.2 / 10

Discoverability 5.6 / 9

Regulatory Posture 3.4 / 15

Agent readiness — 39/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 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 Horizontal (data, software, accessibility, platform) 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):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks

5 more unmet checks in the Agent Readiness table above.

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

Operational Transparency scores 5.3 — up to +12.3 composite points
Contract Quality scores 56.7 — up to +10.8 composite points
Contract Governance scores 22.0 — up to +9.4 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/e2a-dev/apis.yml: open an issue on github.com/api-evangelist/e2a-dev 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 2

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

e2a.dev Email API

Open-source email API for sending transactional emails and managing inboxes.

e2a API API

e2a — authenticated email gateway for AI agents. v1 contract.

Pricing Plans 1

Published pricing tiers and plan structures.

E2A Dev Plans Pricing

4 plans

PLANS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

E2A Dev Context

120 classes · 303 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

e2a-dev API Rules

13 rules · 10 errors 2 warnings 1 info

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

ContactEngagementView

18 properties

JSON SCHEMA

ForwardRequest

10 properties

JSON SCHEMA

MessageView

33 properties

JSON SCHEMA

ReplyRequest

11 properties

JSON SCHEMA

SendEmailRequest

14 properties

JSON SCHEMA

VerifyDomainView

6 properties

JSON SCHEMA

Security Posture 2

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

E2A Dev Authentication

1 scheme

SECURITY

E2A Dev Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgentSkill

AgentSkill

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 8

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

Conformance

DataModel

Idempotency

Conventions

ErrorCatalog

Scroll for all 8

Build 3

SDKs, sample code, and the tooling you integrate with

Packages

Packages

SDKs

SDKs

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

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 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: e2a-dev
name: e2a-dev
image: https://e2a.dev/og-image.png
description: e2a.dev provides an open-source email API designed for applications and AI agents. It enables sending transactional
  emails, managing two-way inboxes, and integrating email workflows into products. Available as a hosted service or self‑hosted
  under Apache‑2.0, it targets developers, agent‑native teams, and businesses seeking flexible, privacy‑focused email solutions.
url: https://artifacts.apis.io/e2a-dev/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-30 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-30'
modified: '2026-10-30'
tags:
- Company
- Email
- OpenSource
- API
- AI
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Spectral
  url: rules/e2a-dev-rules.yml
- type: JSONLD
  url: json-ld/e2a-dev-context.jsonld
- type: Vocabulary
  url: vocabulary/e2a-dev-vocabulary.yml
- type: Conformance
  url: conformance/e2a-dev-conformance.yml
- type: Plans
  url: plans/e2a-dev-plans-pricing.yml
- type: AgentSkill
  url: skills/_index.yml
- type: DataModel
  url: data-model/e2a-dev-data-model.yml
- type: Idempotency
  url: conventions/e2a-dev-conventions.yml
- type: Conventions
  url: conventions/e2a-dev-conventions.yml
- type: Authentication
  url: authentication/e2a-dev-authentication.yml
- type: ErrorCatalog
  url: errors/e2a-dev-problem-types.yml
- type: LLMsTxt
  url: llms/e2a-dev-llms.txt
- type: WellKnown
  url: well-known/e2a-dev-well-known.yml
- type: Hosts
  url: hosts/e2a-dev-hosts.yml
- type: Vendors
  url: vendors/e2a-dev-vendors.yml
- type: Packages
  url: packages/e2a-dev-packages.yml
- type: SDKs
  url: https://www.npmjs.com/package/@e2a/sdk
- type: DomainSecurity
  url: security/e2a-dev-domain-security.yml
- type: Website
  url: https://e2a.dev/
- type: Documentation
  url: https://e2a.dev/api-docs
- type: APIReference
  url: https://e2a.dev/api-docs
- type: GettingStarted
  url: https://e2a.dev/get-started
- type: Pricing
  url: https://e2a.dev/pricing
- type: Blog
  url: https://e2a.dev/blog
- type: GitHubOrganization
  url: https://github.com/tokencanopy
- type: TermsOfService
  url: https://tokencanopy.com/terms
- type: PrivacyPolicy
  url: https://e2a.dev/privacy
apis:
- name: e2a.dev Email API
  description: Open-source email API for sending transactional emails and managing inboxes.
  humanURL: https://e2a.dev/api-docs
  baseURL: https://e2a.dev/v1
  aid: e2a-dev:e2a-dev-email-api
- aid: e2a-dev:e2a-api-api
  name: e2a API API
  description: e2a — authenticated email gateway for AI agents. v1 contract.
  humanURL: https://e2a.dev/openapi.yaml
  baseURL: https://api.e2a.dev
  properties:
  - type: OpenAPI
    url: openapi/_original/e2a-dev-api-openapi.yml
  - type: JSONSchema
    url: json-schema/e2a-dev-message-view-schema.json
  - type: JSONSchema
    url: json-schema/e2a-dev-send-email-request-schema.json
  - type: JSONSchema
    url: json-schema/e2a-dev-reply-request-schema.json
  - type: JSONSchema
    url: json-schema/e2a-dev-forward-request-schema.json
  - type: JSONSchema
    url: json-schema/e2a-dev-contact-engagement-view-schema.json
  - type: JSONSchema
    url: json-schema/e2a-dev-verify-domain-view-schema.json
x-coverage:
  state: gated
  reason: partner-login
  method: derived
  generated: '2026-10-30'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company serves an API surface but requires credentials before any description of it can be read
  evidence:
  - url: https://e2a.dev/openapi.yaml
    status: null
  - url: https://staging.e2a.dev/v1/openapi.json
    status: null
  - url: https://api.e2a.dev/v1/openapi.json
    status: null
  - url: https://api.e2a.dev/mcp
    status: 401
  - url: https://e2a.dev/
    status: 200
x-enrichment:
  date: '2026-10-30'
  status: enriched
  artifacts_added: 24
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

e2a-dev API — frequently asked questions

Does e2a-dev have an API?

Yes. APIs.io lists 2 APIs from e2a-dev, including e2a.dev Email API and e2a API API.

Is there an OpenAPI specification for the e2a-dev API?

Yes. APIs.io indexes 1 OpenAPI specification for e2a-dev, each linked for download from this page.

How do I authenticate with the e2a-dev API?

e2a-dev documents its authentication (1 scheme). The details are profiled on APIs.io as E2A Dev Authentication.

How much does the e2a-dev API cost?

APIs.io lists 4 pricing plans for e2a-dev, with each plan's price, limits and inclusions under Pricing Plans on this page.

Is the e2a-dev API ready for AI agents?

e2a-dev has a Kin Score of 49.2 out of 100 (developing) and an Agent Readiness score of 38.8 (agent-ready), scored by API Evangelist on 2026-10-31.

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