# NeverBounce

**Canonical:** https://apis.io/providers/neverbounce/  
**Website:** https://www.neverbounce.com  
**APIs profiled:** 5

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.

## Kin Score — 62.6 / 100 (strong)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 62.6).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 62.9 |
| Governance | 16.7 |
| Contract Governance | 16.7 |
| Operational Transparency | 81.6 |
| Developer Ergonomics | 54.2 |
| Commercial Clarity | 76.3 |
| Access Clarity | 76.3 |

## Agent readiness — 48.8 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | documented |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | documented |
| OpenAPI Examples | verified |
| Rate Limit Signal | documented |
| Event Surface Described | yes |
| Agent Skills | derived |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Self-serve signup with published per-credit pricing — onboarding: self-serve, pricing: paid, trial: yes (confidence: high).

## APIs (5)

- **NeverBounce API v4** — RESTful JSON API for email verification. Provides single email verification (`/single/check`), bulk job verification (`/jobs/create`, `/jobs/parse`, `/jobs/start`, `/jobs/status...
- **NeverBounce Account API** — Account credit balances and job counts by state.
- **NeverBounce Jobs API** — Bulk list verification jobs — create, parse, start, status, results, search, delete, download.
- **NeverBounce Single API** — Real-time verification of a single email address.
- **NeverBounce POE API** — Proof of Engagement. Server-side confirmation that a verification produced by the browser JavaScript widget genuinely came from NeverBounce, using the transaction_id and confirm...

## MCP servers (1)

- **NeverBounce Developer Docs MCP**

## Agentic access (1)

- **Neverbounce Agentic Access** — 10 operations · 5 acting

## Security (2)

- **Neverbounce Authentication** — apiKey · 1 scheme
- **Neverbounce Domain Security** — TLSv1.3 · HSTS · DMARC

## Plans (1)

- **Neverbounce Plans Pricing**

## Tags

Email Verification, Email Validation, Email Hygiene, Deliverability, Marketing, List Cleaning, Data Quality, ZoomInfo

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/neverbounce/). Scores are computed from the provider's own public artifacts under a published rubric.