_done email verifier API
The email verifier API from _done -- 1 operation. POST /verify takes one email address and returns a deliverability verdict (valid/risky/invalid), splits username and domain, and flags free-provider domains and role accounts. Verified 2026-09-03: the spec resolves, an invented control path 404s, and an unpaid POST /verify answers 402 -- the x402 door works as the catalog describes. Submitted by the provider via apis.io/add (1a293a63); the build gate parked it as a curated-record collision and it was merged by hand, which is the designed path.
_done email verifier API is one of 28 APIs that _done publishes on the APIs.io network, described by a machine-readable OpenAPI specification.
Tagged areas include Email Verification. The published artifact set on APIs.io includes an OpenAPI specification and API documentation.
This API exposes 1 operation across 1 path, and defines 4 schemas. It is described by OpenAPI 3.1.0, at version 1.0.0.
Requests are made against a single base URL, https://email-verifier.underscoredone.com.
Metadata
The identity and technical contract details declared by the specification.
Authentication & Security 1
_done email verifier API declares
1 security scheme
for authenticating requests.
An API key is passed in the header as SIGN-IN-WITH-X (siwx).
siwx— CAIP-122 wallet signature for repeat access after payment
Paths & Operations 1
Across 1 path, the API surfaces 1 operation — 1 POST. Each is listed below with its method, path, parameters, and response codes.
Schemas 4
The contract defines 4 schemas that model the data the API accepts and returns. The most detailed are Response (7 properties), ValidationError (5 properties), Request (1 property), HTTPValidationError (1 property). Each schema is shown below with its type and property counts.
Specification
The full machine-readable OpenAPI contract behind this narrative.
Source
More from _done 12
Other APIs _done publishes across the network.
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