Inputs & Authorization

Fideo's Verify and Signals APIs share the same multi-field request schema. You can pass any combination of identifiers (email, phone, name + address, profile URLs, MAIDs, etc.) in a single payload and the platform will return the richest possible intelligence for that identity.

Minimum viable request

Send at least one email, phone, social handle/ID, or a combined name + postal address. More identifiers dramatically improve both match accuracy and the number of Signals/Verify checks we can evaluate.

High-confidence responses depend on both what you send and how you secure each request:

• Multi-field inputs covers every supported field, including hashing requirements, field dependencies (e.g., when names must be paired with postal addresses), platform-specific options like country filters, and guidance on when to send arrays versus single values.
• Authorization explains how to provision API keys in ReadMe, authenticate with Authorization: Bearer {API_KEY} headers, rotate secrets, and isolate your sandbox vs. production traffic.

Why a shared payload?

• Consistency across products. The MultiFieldReq schema defined in our OpenAPI spec is accepted by both POST /verify and POST /signals, so you only have to build one integration.
• Best-match logic. We use deterministic matching when you send exact identifiers (like hashed emails) and probabilistic linking when you provide broader context (like a name plus postal address). Sending multiple identifiers increases match confidence and unlocks more downstream checks.
• Optional country filtering. Signals supports request-time countries and excludedCountries lists so you can gate results by geography without changing your Verify implementation.

If you are migrating from FullContact, the payloads are nearly identical. The few Fideo-specific differences are called out in the tables on the following pages.