InboxTrue

InboxTrue provides email verification services, allowing users to validate email addresses individually or in bulk, even on catch‑all domains. The platform returns a verdict and supporting signals, offering free single checks and up to 1,000 free bulk validations each month. It targets developers and businesses needing reliable email hygiene for sign‑ups, newsletters, and outreach, emphasizing privacy and accuracy.

InboxTrue publishes 2 API contracts indexed on the APIs.io network: Email API and Zeroclick API. Tagged areas include Company, Email Verification, Software-as-a-Service, and Developer Tools.

The InboxTrue catalog on APIs.io includes 1 Spectral governance ruleset.

InboxTrue’s developer surface includes authentication, getting-started guide, documentation, signup flow, and 16 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

42.5/100 developing Agent 43/100 agent ready Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemium

1 published contract

Company Email Verification Software-as-a-Service Developer Tools

Kin Score

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

Composite quality — 42.5/100 · developing

Contract Quality 11.3 / 21

Developer Ergonomics 7.3 / 17

Access Clarity 9.0 / 17

Operational Transparency 1.3 / 11

Contract Governance 1.9 / 10

Discoverability 4.9 / 9

Regulatory Posture 2.8 / 15

Agent readiness — 43/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 6 / 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 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

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/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/inboxtrue-com/"><img src="https://apis.io/badge/inboxtrue-com/card.svg" alt="InboxTrue on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Raise your score.

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 →
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 →
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 →
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too Ask about this →
Agent Skills +5 pts — skills artifact present, graded by who authored it Ask about this →

4 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 53.2 — up to +11.7 composite points Ask about this →
Operational Transparency scores 11.9 — up to +11.5 composite points Ask about this →
Developer Ergonomics scores 42.9 — up to +11.4 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.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

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/inboxtrue-com/apis.yml: open an issue on github.com/api-evangelist/inboxtrue-com 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 3

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)

Dynamic Client Registration

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

APIs 2

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

InboxTrue Email API

The Email API from InboxTrue — 1 operation(s) for email.

InboxTrue Zeroclick API

The Zeroclick API from InboxTrue — 1 operation(s) for zeroclick.

InboxTrue API pricing

Prices published by InboxTrue, read 2026-11-12 from inboxtrue.com/#pricing.

Plan	Price
Free	$0/ month
1,000–49,000 validations	$3.40
50,000–99,000 validations	$2.98
100,000–249,000 validations	$2.55
250,000–499,000 validations	$2.13
500,000–999,000 validations	$1.70
1,000,000+ validations	$1.45

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

InboxTrue Plans Pricing

7 plans

PLANS

Spectral Rules 1

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

InboxTrue API Rules

46 rules · 44 error-severity 1 warn-severity 1 info-severity

SPECTRAL

Security Posture 2

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

InboxTrue Authentication

1 scheme

SECURITY

InboxTrue Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access (API Evangelist recommendations) 1

Recommended x-agentic-access execution contracts for AI agents.

InboxTrue Agentic Access

2 operations · 1 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

DeveloperPortal

DeveloperPortal

SignUp

SignUp

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Spectral

ErrorCatalog

Conformance

Webhooks

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: inboxtrue-com
name: InboxTrue
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-13'
  method: derived
image: https://inboxtrue.com/brand/inboxtrue-social.png
description: InboxTrue provides email verification services, allowing users to validate email addresses individually or in
  bulk, even on catch‑all domains. The platform returns a verdict and supporting signals, offering free single checks and
  up to 1,000 free bulk validations each month. It targets developers and businesses needing reliable email hygiene for sign‑ups,
  newsletters, and outreach, emphasizing privacy and accuracy.
url: https://artifacts.apis.io/inboxtrue-com/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-12 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-12'
modified: '2026-11-12'
tags:
- Company
- Email Verification
- Software-as-a-Service
- Developer Tools
tags_raw:
- Company
- EmailVerification
- API
- SaaS
- DeveloperTools
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/inboxtrue-com-agentic-access.yml
- type: Plans
  url: plans/inboxtrue-com-plans-pricing.yml
- type: Spectral
  url: rules/inboxtrue-com-rules.yml
- type: Authentication
  url: authentication/inboxtrue-com-authentication.yml
- type: ErrorCatalog
  url: errors/inboxtrue-com-problem-types.yml
- type: Conformance
  url: conformance/inboxtrue-com-conformance.yml
- type: LLMsTxt
  url: llms/inboxtrue-com-llms.txt
- type: WellKnown
  url: well-known/inboxtrue-com-well-known.yml
- type: Hosts
  url: hosts/inboxtrue-com-hosts.yml
- type: Vendors
  url: vendors/inboxtrue-com-vendors.yml
- type: Webhooks
  url: https://inboxtrue.com/webhooks
- type: TermsOfService
  url: https://inboxtrue.com/terms
- type: GettingStarted
  url: https://inboxtrue.com/#developers
- type: DeveloperPortal
  url: https://api.inboxtrue.com</code
- type: GitHubOrganization
  url: https://github.com/inboxtrue
- type: DomainSecurity
  url: security/inboxtrue-com-domain-security.yml
- type: Website
  url: https://inboxtrue.com/
- type: Documentation
  url: https://inboxtrue.com/docs
- type: SignUp
  url: https://inboxtrue.com/register
- type: PrivacyPolicy
  url: https://inboxtrue.com/privacy
apis:
- aid: inboxtrue-com:inboxtrue-com-email-api
  name: InboxTrue Email API
  description: The Email API from InboxTrue — 1 operation(s) for email.
  humanURL: https://agents.inboxtrue.com/openapi.json
  baseURL: https://agents.inboxtrue.com
  tags:
  - Email
  properties:
  - type: OpenAPI
    url: openapi/inboxtrue-com-email-api-openapi.yml
- aid: inboxtrue-com:inboxtrue-com-zeroclick-api
  name: InboxTrue Zeroclick API
  description: The Zeroclick API from InboxTrue — 1 operation(s) for zeroclick.
  humanURL: https://agents.inboxtrue.com/openapi.json
  baseURL: https://agents.inboxtrue.com
  tags:
  - Zeroclick
  properties:
  - type: OpenAPI
    url: openapi/inboxtrue-com-zeroclick-api-openapi.yml
x-enrichment:
  date: '2026-11-12'
  status: nochange
  artifacts_added: 0
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

InboxTrue API — frequently asked questions

Does InboxTrue have an API?

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

Is there an OpenAPI specification for the InboxTrue API?

Yes. APIs.io indexes 2 OpenAPI specifications for InboxTrue, each linked for download from this page.

How do I authenticate with the InboxTrue API?

InboxTrue documents its authentication (1 scheme). The details are profiled on APIs.io as InboxTrue Authentication.

How much does the InboxTrue API cost?

InboxTrue publishes its prices; its Free plan is $0/ month as of 2026-11-12. APIs.io lists 7 pricing plans for InboxTrue, with each plan's price, limits and inclusions under Pricing on this page.

Is the InboxTrue API ready for AI agents?

InboxTrue has a Kin Score of 42.5 out of 100 (developing) and an Agent Readiness score of 43.1 (agent-ready), scored by API Evangelist on 2026-11-13.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/inboxtrue-com"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/inboxtrue-com/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/inboxtrue-com/evidence"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.