Full lookup for a single number: registration status plus the public identity of the account when registered — ACI (Account Identifier UUID), PNI (Phone Number Identifier, usually PNI:<uuid>), optional plaintext profile metadata (identityKey, unrestrictedUnidentifiedAccess, capabilities, badges), a machine status (found / not_found / timeout / ...), a human-readable message, and durationMs. fieldsEncrypted=true for strangers indicates that display name / about / avatar are withheld by Signal's end-to-end profile encryption (not a tool limitation). Use this when you need identity enrichment, not just a yes/no.

API Features

Stable identifiers (ACI/PNI) Returns ACI and PNI UUIDs you can use for deduplication, linking, and identity resolution

Public profile metadata When available, returns identityKey, unrestrictedUnidentifiedAccess, capabilities, and badges

Clear registration status registered plus machine status (found / not_found / timeout / ...) and a human-readable message

Privacy-aware fieldsEncrypted=true honestly reflects that name/about/avatar are not available without a shared profile key

Live API Demo

GET /api/project/signal/user-info

API Response (JSON)

{}

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If you encounter API issues or need other API requirements, please contact us.

Use Cases

Identity resolution: use stable ACI/PNI UUIDs to deduplicate and link records
Contact enrichment: append Signal identity metadata to CRM records
Risk and trust scoring: leverage registration status and capabilities in fraud or quality checks
Lead scoring: combine registration status with identity data before outreach

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Get Signal Identity by Number

API Features

Live API Demo

API Response (JSON)

Use Cases