Fixture Email

Fixture Email provides a platform for testing email integrations. It offers real inboxes that can send and receive actual email, enabling end‑to‑end testing of email workflows. The service is AI‑native, allowing coding agents to automatically create, manage, and assert on email messages without manual setup. It aims to replace traditional email testing services with a developer‑friendly API and extensive tooling for automated test suites.

Fixture Email is listed with 2 APIs on the APIs.io network. Tagged areas include Company, Email, Testing, and Artificial Intelligence.

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

Fixture Email’s developer surface includes documentation, engineering blog, and 14 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

22.5/100 emerging Agent 22/100 agent aware Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

2 APIs

Company Email Testing Artificial Intelligence

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 22.5/100 · emerging

Contract Quality 5.5 / 21

Developer Ergonomics 2.0 / 17

Access Clarity 4.7 / 17

Operational Transparency 0.0 / 11

Contract Governance 2.2 / 10

Discoverability 5.0 / 9

Regulatory Posture 1.8 / 15

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 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 0 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 0 / 3

MCP Tool Quality 6 / 6

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 Ask about this →
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author Ask about this →
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) Ask about this →
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented) Ask about this →

10 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 26.0 — up to +18.5 composite points Ask about this →
Developer Ergonomics scores 11.9 — up to +17.6 composite points Ask about this →
Access Clarity scores 27.7 — up to +14.5 composite points Ask about this →

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.

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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/fixture-email/apis.yml: open an issue on github.com/api-evangelist/fixture-email 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 →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

APIs 2

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

Fixture Email API

Fixture Email provides a developer API documented at the Docs page.

Fixture Email API

Fixture Email API as documented publicly: 28 operations. Contract generated from the documentation by API Evangelist (2026-11-08); not the provider's own document.

Semantic Vocabularies 1

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

Fixture Email Context

7 classes · 10 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

Fixture Email API Rules

45 rules · 41 error-severity 1 warn-severity 3 info-severity

SPECTRAL

JSON Schema 6

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

GetApiCallbacksResponse

1 properties

JSON SCHEMA

GetApiMailboxesMailboxCancelCleanupResponse

1 properties

JSON SCHEMA

GetApiMailboxesMailboxEnableResponse

2 properties

JSON SCHEMA

GetApiMailboxesMailboxResponse

3 properties

JSON SCHEMA

PostApiAttachmentsUploadResponse

1 properties

JSON SCHEMA

PostApiSendRequest

3 properties

JSON SCHEMA

Security Posture 1

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

Fixture Email Domain Security

TLSv1.3 · DNSSEC · DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

Login

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

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Conformance

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

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: fixture-email
name: Fixture Email
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  probe_state: gated
  source:
  - security
  generated: '2026-11-13'
  method: derived
image: https://fixture.email/og-card.png
description: Fixture Email provides a platform for testing email integrations. It offers real inboxes that can send and receive
  actual email, enabling end‑to‑end testing of email workflows. The service is AI‑native, allowing coding agents to automatically
  create, manage, and assert on email messages without manual setup. It aims to replace traditional email testing services
  with a developer‑friendly API and extensive tooling for automated test suites.
url: https://artifacts.apis.io/fixture-email/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-08 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-08'
modified: '2026-11-08'
tags:
- Company
- Email
- Testing
- Artificial Intelligence
tags_raw:
- Company
- Email
- Testing
- API
- AI
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Spectral
  url: rules/fixture-email-rules.yml
- type: JSONLD
  url: json-ld/fixture-email-context.jsonld
- type: Vocabulary
  url: vocabulary/fixture-email-vocabulary.yml
- type: DataModel
  url: data-model/fixture-email-data-model.yml
- type: Conformance
  url: conformance/fixture-email-conformance.yml
- type: LLMsTxt
  url: llms/fixture-email-llms.txt
- type: WellKnown
  url: well-known/fixture-email-well-known.yml
- type: Hosts
  url: hosts/fixture-email-hosts.yml
- type: Vendors
  url: vendors/fixture-email-vendors.yml
- type: Login
  url: https://fixture.email/login
- type: DomainSecurity
  url: security/fixture-email-domain-security.yml
- type: Website
  url: https://fixture.email/
- type: Documentation
  url: https://fixture.email/docs
- type: Blog
  url: https://fixture.email/blog
- type: TermsOfService
  url: https://fixture.email/terms
- type: PrivacyPolicy
  url: https://fixture.email/privacy
apis:
- name: Fixture Email API
  description: Fixture Email provides a developer API documented at the Docs page.
  humanURL: https://fixture.email/docs
  aid: fixture-email:fixture-email-api-2
- aid: fixture-email:fixture-email-api
  name: Fixture Email API
  description: 'Fixture Email API as documented publicly: 28 operations. Contract generated from the documentation by API
    Evangelist (2026-11-08);

    not the provider''s own document.'
  humanURL: https://fixture.email/docs
  baseURL: https://send.fixture.email
  properties:
  - type: OpenAPI
    url: openapi/_ae-authored/fixture-email-openapi-generated.yml
    x-provenance: generated
  - type: JSONSchema
    url: json-schema/fixture-email-get-api-mailboxes-mailbox-enable-response-schema.json
  - type: JSONSchema
    url: json-schema/fixture-email-get-api-mailboxes-mailbox-response-schema.json
  - type: JSONSchema
    url: json-schema/fixture-email-post-api-send-request-schema.json
  - type: JSONSchema
    url: json-schema/fixture-email-get-api-callbacks-response-schema.json
  - type: JSONSchema
    url: json-schema/fixture-email-post-api-attachments-upload-response-schema.json
  - type: JSONSchema
    url: json-schema/fixture-email-get-api-mailboxes-mailbox-cancel-cleanup-response-schema.json
x-coverage:
  state: gated
  reason: auth-required
  detail: API endpoints require authentication and return 401 for OpenAPI and GraphQL probes.
  evidence:
  - url: https://api.fixture.email/openapi.json
    status: 0
  - url: https://fixture.email/api/graphql
    status: 401
  checked: '2026-11-08'
x-enrichment:
  date: '2026-11-08'
  status: enriched
  artifacts_added: 26
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Fixture Email API — frequently asked questions

Does Fixture Email have an API?

Yes. APIs.io lists 2 APIs from Fixture Email, including Fixture Email API and Fixture Email API.

Is there an OpenAPI specification for the Fixture Email API?

Yes. APIs.io indexes 1 OpenAPI specification for Fixture Email, each linked for download from this page.

How do I authenticate with the Fixture Email API?

Fixture Email uses bearer-token authentication.

Is the Fixture Email API ready for AI agents?

Fixture Email has a Kin Score of 22.5 out of 100 (emerging) and an Agent Readiness score of 21.5 (agent-aware), scored by API Evangelist on 2026-11-13.

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