Return Path
Return Path is an email-deliverability and inbox-intelligence brand that pioneered sender reputation, inbox-placement monitoring, and email fraud protection for marketers and email senders. Founded in 1999 and backed by Sapphire Ventures and Union Square Ventures, Return Path was acquired by Validity in 2019 and now ships as the Validity Everest email-success platform; returnpath.com 301-redirects to validity.com. The platform draws on signals from billions of global mailboxes to measure inbox placement, sender reputation, and deliverability across major mailbox providers. The Return Path product line's surviving API surface is the Everest API at api.everest.validity.com — 170 published operations across inbox placement, sender reputation and Sender Score, blocklist and spam-trap monitoring, DMARC infrastructure reporting, engagement analytics, list validation and certification. Validity publishes no OpenAPI, but it does publish a complete public Postman collection at developer.everest.validity.com, which is the machine-readable contract this profile is built from.
Return Path is listed with 11 APIs on the APIs.io network, including Account Services API, Apps & Integrations API, Certification API, and 8 more. Tagged areas include Company, MarTech, Email, Email Deliverability, and Email Marketing.
The Return Path catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.
Return Path’s developer surface includes engineering blog, support, documentation, API reference, authentication, and 29 more developer resources.
Kin Score
Kin Score
How this is scored →scored 2026-11-06 · rubric v0.27.0
It updates itself when the score changes. Paste this where you link to your API docs:
<a href="https://apis.io/providers/return-path/"><img src="https://apis.io/badge/return-path/card.svg" alt="Return Path on APIs.io — Kin Score by API Evangelist"></a>Other styles, a README pill and a shields.io endpoint are on the badge page.
- MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
- Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
- 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 - Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
- Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)
- Contract Quality scores 24.9 — up to +18.8 composite points
- Access Clarity scores 50.0 — up to +10.0 composite points
- Contract Governance scores 18.2 — up to +9.8 composite points
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.
APIs 11
Individual APIs this provider publishes, each with its own machine-readable definition.
Return Path Account Services API
The Account Services API from Return Path — 13 operation(s) for account services.
Return Path Apps & Integrations API
The Apps & Integrations API from Return Path — 12 operation(s) for apps & integrations.
Return Path Certification API
The Certification API from Return Path — 2 operation(s) for certification.
Return Path Competitive Intel API
The Competitive Intel API from Return Path — 7 operation(s) for competitive intel.
Return Path Engagement API
The Engagement API from Return Path — 35 operation(s) for engagement.
Return Path Inbox Placement API
The Inbox Placement API from Return Path — 17 operation(s) for inbox placement.
Return Path Infrastructure (DMARC) API
The Infrastructure (DMARC) API from Return Path — 10 operation(s) for infrastructure (dmarc).
Return Path Legacy API (1.0) API
The Legacy API (1.0) API from Return Path — 6 operation(s) for legacy api (1.0).
Return Path List Validation API
The List Validation API from Return Path — 6 operation(s) for list validation.
Return Path Reputation API
The Reputation API from Return Path — 18 operation(s) for reputation.
Return Path View Time Optimization API
The View Time Optimization API from Return Path — 4 operation(s) for view time optimization.
Scroll for all 11
Agent Skills 3
Packaged agent skills for driving this provider's APIs from an AI assistant.
Diagnose an inbox placement drop
AGENT SKILLSet up and monitor sender reputation
AGENT SKILLReturn Path API pricing
Pricing Plans 1
Published pricing tiers and plan structures.
Rate Limits 1
Documented rate limits and quota policies.
Return Path Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals for API financial operations.
Return Path Finops
FINOPSEvent Specifications 1
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Return Path Webhooks
ASYNCAPISpectral Rules 1
Spectral governance rulesets for linting and validating these APIs.
Return Path API Rules
SPECTRALOpenAPI Overlays 1
Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.
Return Path Everest Api Overlay
DERIVEDSecurity Posture 4
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Return Path Trust Center
SOC 2 Type 2, ISO/IEC 27001, ISO/IEC 27701, GDPR, CCPA, EU-US Data Privacy Framework, Microsoft SSPA, Standard Contractual Clauses
SECURITYResources
Get Started 2
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 2
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 9
Authentication, authorization, and security posture
Scroll for all 9
Operate 4
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 2
The organization behind the API
Other 2
Properties that don't map to a standard resource type
Source (apis.yml)
Return Path API — frequently asked questions
Does Return Path have an API?
Yes. APIs.io lists 11 APIs from Return Path, including Return Path Account Services API, Return Path Apps & Integrations API and Return Path Certification API, and 8 more.
Is there an OpenAPI specification for the Return Path API?
Yes. APIs.io indexes 11 OpenAPI specifications for Return Path, each linked for download from this page.
How do I authenticate with the Return Path API?
Return Path uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Return Path Authentication.
Is the Return Path API ready for AI agents?
Return Path has a Kin Score of 46.9 out of 100 (developing) and an Agent Readiness score of 33.2 (agent-ready), scored by API Evangelist on 2026-11-06.
Work with this as data
Every provider here is available over the APIs.io API and to AI agents over MCP.