NeverBounce

NeverBounce is an email verification and list cleaning service — a ZoomInfo company — that validates individual email addresses in real time and cleans bulk lists by checking syntax, mailbox existence, role addresses, disposable addresses, catch-all domains, and deliverability to reduce bounce rates for marketing, sales, and transactional senders. The NeverBounce v4 REST API at https://api.neverbounce.com/v4.2/ provides ten published operations covering single email checks (/single/check), bulk list jobs (create, parse, start, status, results, search, delete, download), account credit info, and the Proof-of-Engagement confirmation used by the browser widget, with JSON responses over HTTPS. Authentication uses a per-integration API key (format `secret_xxxx...`) passed as the `key` parameter in the query string or request body; `public_` keys drive the JavaScript widget and cannot call the standard API. Application errors — including authentication failure and throttling — are returned with an HTTP 200 and a `status` field rather than a 4xx, which is the defining runtime quirk of this API.

NeverBounce publishes 4 APIs on the APIs.io network, including Account API, Jobs API, Single API, and 1 more. Tagged areas include Email Verification, Email Validation, Email Hygiene, Deliverability, and Marketing.

The NeverBounce catalog on APIs.io includes 1 event-driven AsyncAPI specification.

NeverBounce’s developer surface includes authentication, CLI, changelog, documentation, API reference, getting-started guide, pricing, and 29 more developer resources.

🌐 Visit website 📡 Source on GitHub

62.6/100 strong ▬ flat Agent 49/100 agent ready Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0

AccessPaidSelf serveFree trial

5 APIs 1 MCP Servers

Email Verification Email ValidationEmail HygieneDeliverability MarketingList CleaningData QualityZoomInfo

Kin Score

Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0

Composite quality — 62.6/100 · strong

Contract Quality 15.7 / 25

Developer Ergonomics 10.8 / 20

Access Clarity 15.3 / 20

Operational Transparency 10.6 / 13

Contract Governance 2.0 / 12

Discoverability 8.2 / 10

Agent readiness — 49/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 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

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/neverbounce: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 5

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

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Rate Limits 1

Documented rate limits and quota policies.

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Signup

Signup

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

MCPServer

AgentSkill

LLMsTxt

LlmsText

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Components

Conventions

ErrorCatalog

DataModel

Conformance

Lifecycle

Webhooks

Scroll for all 7

Build 5

SDKs, sample code, and the tooling you integrate with

Packages

SDKs

CLI

ToolCrosswalk

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 5

Status, limits, changes, and where to get help

Deprecation

StatusPage

ChangeLog

RateLimits

Support

Commercial 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

PrivacyPolicy

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: neverbounce
name: NeverBounce
description: NeverBounce is an email verification and list cleaning service — a ZoomInfo company — that validates individual
  email addresses in real time and cleans bulk lists by checking syntax, mailbox existence, role addresses, disposable addresses,
  catch-all domains, and deliverability to reduce bounce rates for marketing, sales, and transactional senders. The NeverBounce
  v4 REST API at https://api.neverbounce.com/v4.2/ provides ten published operations covering single email checks (/single/check),
  bulk list jobs (create, parse, start, status, results, search, delete, download), account credit info, and the Proof-of-Engagement
  confirmation used by the browser widget, with JSON responses over HTTPS. Authentication uses a per-integration API key (format
  `secret_xxxx...`) passed as the `key` parameter in the query string or request body; `public_` keys drive the JavaScript
  widget and cannot call the standard API. Application errors — including authentication failure and throttling — are returned
  with an HTTP 200 and a `status` field rather than a 4xx, which is the defining runtime quirk of this API.
type: Index
accessModel:
  pricing: paid
  onboarding: self-serve
  trial: true
  try_now: false
  public: true
  label: Self-serve signup with published per-credit pricing
  confidence: high
  source:
  - authentication
  - plans/neverbounce-plans-pricing.yml
  - https://www.neverbounce.com/pricing
  generated: '2026-08-13'
  method: searched
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/neverbounce.png
tags:
- Email Verification
- Email Validation
- Email Hygiene
- Deliverability
- Marketing
- List Cleaning
- Data Quality
- ZoomInfo
url: https://raw.githubusercontent.com/api-evangelist/neverbounce/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-08-13'
specificationVersion: '0.23'
apis:
- aid: neverbounce:v4-api
  name: NeverBounce API v4
  description: RESTful JSON API for email verification. Provides single email verification (`/single/check`), bulk job verification
    (`/jobs/create`, `/jobs/parse`, `/jobs/start`, `/jobs/status`, `/jobs/results`, `/jobs/search`, `/jobs/delete`, `/jobs/download`),
    account credit info, and Proof-of-Engagement (`/poe/confirm`) endpoints. GET and POST are interchangeable; PUT and DELETE
    are unsupported. Authentication uses a per-integration API key (`secret_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx`) passed via
    the `key` query/body parameter.
  humanURL: https://developers.neverbounce.com/docs/api-getting-started
  baseURL: https://api.neverbounce.com/v4
  tags:
  - Email Verification
  - REST
  - JSON
  - Deliverability
  properties:
  - type: Documentation
    url: https://developers.neverbounce.com/docs/api-getting-started
  - type: APIReference
    url: https://developers.neverbounce.com/reference/getting-started
  - type: Verifying an Email
    url: https://developers.neverbounce.com/docs/verifying-an-email
  - type: Verifying a List
    url: https://developers.neverbounce.com/docs/verifying-a-list
  - type: GitHub SDKs
    url: https://github.com/NeverBounce
- aid: neverbounce:neverbounce-account-api
  name: NeverBounce Account API
  description: Account credit balances and job counts by state.
  humanURL: https://developers.neverbounce.com/reference/account-info
  baseURL: https://api.neverbounce.com/v4
  tags:
  - Account
  properties:
  - type: OpenAPI
    url: openapi/neverbounce-account-api-openapi.yml
  - type: Overlay
    url: overlays/neverbounce-account-overlay.yaml
- aid: neverbounce:neverbounce-jobs-api
  name: NeverBounce Jobs API
  description: Bulk list verification jobs — create, parse, start, status, results, search, delete, download.
  humanURL: https://developers.neverbounce.com/reference/jobs
  baseURL: https://api.neverbounce.com/v4
  tags:
  - Job
  tags_raw:
  - Jobs
  properties:
  - type: OpenAPI
    url: openapi/neverbounce-jobs-api-openapi.yml
  - type: Overlay
    url: overlays/neverbounce-jobs-overlay.yaml
  - type: Webhooks
    url: asyncapi/neverbounce-webhooks.yml
- aid: neverbounce:neverbounce-single-api
  name: NeverBounce Single API
  description: Real-time verification of a single email address.
  humanURL: https://developers.neverbounce.com/reference/single-check
  baseURL: https://api.neverbounce.com/v4
  tags:
  - Single
  properties:
  - type: OpenAPI
    url: openapi/neverbounce-single-api-openapi.yml
  - type: Overlay
    url: overlays/neverbounce-single-overlay.yaml
- aid: neverbounce:neverbounce-poe-api
  name: NeverBounce POE API
  description: Proof of Engagement. Server-side confirmation that a verification produced by the browser JavaScript widget
    genuinely came from NeverBounce, using the transaction_id and confirmation_token the widget issues.
  humanURL: https://developers.neverbounce.com/reference/widget-poe-confirm
  baseURL: https://api.neverbounce.com/v4
  tags:
  - POE
  - Widget
  properties:
  - type: OpenAPI
    url: openapi/neverbounce-poe-api-openapi.yml
  - type: Overlay
    url: overlays/neverbounce-poe-overlay.yaml
common:
- type: AgenticAccess
  url: agentic-access/neverbounce-agentic-access.yml
- type: DomainSecurity
  url: security/neverbounce-domain-security.yml
- type: Authentication
  url: authentication/neverbounce-authentication.yml
- type: Packages
  url: packages/neverbounce-packages.yml
- type: SDKs
  url: packages/neverbounce-packages.yml
- type: CLI
  url: cli/neverbounce-cli.yml
- type: Components
  url: components/neverbounce-components.yml
- type: Conventions
  url: conventions/neverbounce-conventions.yml
- type: ErrorCatalog
  url: errors/neverbounce-problem-types.yml
- type: DataModel
  url: data-model/neverbounce-data-model.yml
- type: Conformance
  url: conformance/neverbounce-conformance.yml
- type: Lifecycle
  url: lifecycle/neverbounce-lifecycle.yml
- type: Deprecation
  url: lifecycle/neverbounce-lifecycle.yml
- type: StatusPage
  url: https://status.neverbounce.com
- type: ChangeLog
  url: changelog/neverbounce-changelog.yml
- type: Plans
  url: plans/neverbounce-plans-pricing.yml
- type: RateLimits
  url: rate-limits/neverbounce-rate-limits.yml
- type: Webhooks
  url: asyncapi/neverbounce-webhooks.yml
- type: MCPServer
  url: mcp/neverbounce-mcp.yml
- type: ToolCrosswalk
  url: mcp/neverbounce-tool-crosswalk.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/neverbounce-llms.txt
- type: LlmsText
  url: https://developers.neverbounce.com/llms.txt
- type: LinkedIn
  url: https://www.linkedin.com/company/neverbounce
- type: Website
  url: https://www.neverbounce.com
- type: Documentation
  url: https://developers.neverbounce.com/
- type: DeveloperPortal
  url: https://developers.neverbounce.com/
- type: APIReference
  url: https://developers.neverbounce.com/reference/getting-started
- type: GettingStarted
  url: https://developers.neverbounce.com/docs/api-getting-started
- type: GitHubOrganization
  url: https://github.com/NeverBounce
- type: Pricing
  url: https://www.neverbounce.com/pricing
- type: Signup
  url: https://app.neverbounce.com/register
- type: Support
  url: https://www.neverbounce.com/contact
- type: Blog
  url: https://www.neverbounce.com/blog
- type: TermsOfService
  url: https://www.neverbounce.com/terms-of-use
- type: PrivacyPolicy
  url: https://www.zoominfo.com/legal/privacy-policy
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 26
  pass: local-v1

NeverBounce

Kin Score

APIs 5

NeverBounce API v4

NeverBounce Account API

NeverBounce Jobs API

NeverBounce Single API

NeverBounce POE API

Open Collections 5

API Collection

NeverBounce API v4 Account API

NeverBounce API v4 Account Jobs API

NeverBounce API v4 Account Single API

NeverBounce API v4

MCP Servers 1

NeverBounce Developer Docs MCP

Pricing Plans 1

Neverbounce Plans Pricing

Rate Limits 1

Neverbounce Rate Limits

Event Specifications 1

Neverbounce Webhooks

Security Posture 2

Neverbounce Authentication

Neverbounce Domain Security

Agentic Access 1

Neverbounce Agentic Access

Resources