Spark Mail (Readdle)

Spark Mail, developed by Readdle, is a smart email client focused on helping users achieve inbox zero and stay organized. It offers features like a focused inbox, snoozing, smart notifications, and powerful search across iOS, macOS, Android, and Windows platforms, aiming to boost productivity for personal and professional communication.

Spark Mail (Readdle) is listed with 1 API on the APIs.io network. Tagged areas include Email, Productivity, iOS, macOS, and Android.

Spark Mail (Readdle)’s developer surface includes support, pricing, documentation, engineering blog, and 9 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

26.6/100 thin Agent 3/100 human only Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

1 API

Email Productivity iOS macOS Android

Kin Score

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

Composite quality — 26.6/100 · thin

Contract Quality 0.0 / 21

Developer Ergonomics 2.8 / 17

Access Clarity 10.7 / 17

Operational Transparency 1.2 / 11

Contract Governance 1.9 / 10

Discoverability 4.9 / 9

Regulatory Posture 3.7 / 15

Agent readiness — 3/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 0 / 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 0 / 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 0 / 5

Registration Without a Human 0 / 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):

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
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
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

12 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 16.7 — up to +16.7 composite points
Operational Transparency scores 10.5 — up to +11.6 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/readdle-spark/apis.yml: open an issue on github.com/api-evangelist/readdle-spark 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.

Spark Mail API

Spark Mail provides email client features and AI-powered reply capabilities. Documentation is available at the guides page.

Pricing Plans 1

Published pricing tiers and plan structures.

Readdle Spark Plans Pricing

4 plans

PLANS

Security Posture 2

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

Readdle Spark Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Readdle Spark Vulnerability Disclosure

no policy recorded

SECURITY

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Conformance

Conformance

Access & Security 3

Authentication, authorization, and security posture

Security

Security

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 4

Pricing, plans, and the legal terms of use

Plans

TermsOfService

PrivacyPolicy

Pricing

Company 2

The organization behind the API

Blog

Blog

Website

Website

Other 1

Properties that don't map to a standard resource type

Hosts

Hosts

Source (apis.yml)

aid: readdle-spark
name: Spark Mail (Readdle)
image: https://cdn-rdstaticassets.readdle.com/assets/spark/spark3/common/share-banner/default.png?1793018697
description: Spark Mail, developed by Readdle, is a smart email client focused on helping users achieve inbox zero and stay
  organized. It offers features like a focused inbox, snoozing, smart notifications, and powerful search across iOS, macOS,
  Android, and Windows platforms, aiming to boost productivity for personal and professional communication.
url: https://raw.githubusercontent.com/api-evangelist/readdle-spark/refs/heads/main/apis.yml
x-type: company
x-source: harvest:new-submission
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-27 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-27'
modified: '2026-10-27'
tags:
- Email
- Productivity
- iOS
- macOS
- Android
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Plans
  url: plans/readdle-spark-plans-pricing.yml
- type: Security
  url: security/readdle-spark-vulnerability-disclosure.yml
- type: Conformance
  url: conformance/readdle-spark-conformance.yml
- type: Hosts
  url: hosts/readdle-spark-hosts.yml
- type: TermsOfService
  url: https://sparkmailapp.com/legal/terms
- type: Support
  url: https://sparkmailapp.com/help
- type: PrivacyPolicy
  url: https://sparkmailapp.com/legal/privacy-web
- type: Pricing
  url: https://sparkmailapp.com/pricing
- type: Documentation
  url: https://sparkmailapp.com/guides/ai-email-reply
- type: Blog
  url: https://sparkmailapp.com/blog
- type: VulnerabilityDisclosure
  url: security/readdle-spark-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/readdle-spark-domain-security.yml
- type: Website
  url: https://sparkmailapp.com/
apis:
- name: Spark Mail API
  description: Spark Mail provides email client features and AI-powered reply capabilities. Documentation is available at
    the guides page.
  humanURL: https://sparkmailapp.com/guides/ai-email-reply
  baseURL: null
  aid: readdle-spark:spark-mail-api
x-submission-probe: 200, 2026-10-26
x-coverage:
  state: unreadable
  reason: no-machine-readable-spec
  detail: The provider's documentation pages are HTML without any published OpenAPI, AsyncAPI, GraphQL, gRPC, or WSDL specifications.
  evidence:
  - url: https://sparkmailapp.com/guides/ai-email-reply
    status: 200
  checked: '2026-10-27'
x-enrichment:
  date: '2026-10-27'
  status: enriched
  artifacts_added: 12
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Spark Mail (Readdle) API — frequently asked questions

Does Spark Mail (Readdle) have an API?

Yes. APIs.io lists 1 API from Spark Mail (Readdle), including Spark Mail API.

How much does the Spark Mail (Readdle) API cost?

APIs.io lists 4 pricing plans for Spark Mail (Readdle), with each plan's price, limits and inclusions under Pricing Plans on this page.

Is the Spark Mail (Readdle) API ready for AI agents?

Spark Mail (Readdle) has a Kin Score of 26.6 out of 100 (thin) and an Agent Readiness score of 3.1 (human-only), scored by API Evangelist on 2026-10-31.

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