aid: callsign
name: CallSign
description: >-
  Callsign is a digital trust platform for fraud prevention, authentication, and
  identity intelligence. Its Intelligence Engine combines behavioral biometrics,
  device fingerprinting, telco intelligence, and threat ensembling with an
  orchestration layer that applies dynamic interventions across customer
  journeys - login and access, online payments, account creation, and Zero Trust
  network access - to recognize and authenticate users passively. The
  Authentication Suite (Callsign One) delivers passwordless, low-friction
  authentication, and the platform targets account takeover, social engineering
  and scams, malware and bots, SIM swap, call divert, and synthetic identity.
  Callsign integrates via REST APIs and web and mobile SDKs, and is certified to
  ISO/IEC 27001 with SOC 2 attestation. Added to the API Evangelist network from
  the Accel portfolio and enriched from Callsign's public developer surface.
url: https://raw.githubusercontent.com/api-evangelist/callsign/refs/heads/main/apis.yml
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://www.callsign.com/media/general-images/in-page-images/_1200x630_crop_center-center_none/Homepage-Account-login-access-person-with-phone-content-1640x1200.jpg
x-type: company
x-source: vc-portfolio
x-backed-by:
- accel
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-18'
tags:
- Company
- Ai
- Identity
- Authentication
- Fraud Prevention
- Behavioral Biometrics
- Security
- Fintech
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: http://www.callsign.com
- type: DeveloperPortal
  url: https://www.callsign.com/developers
- type: Documentation
  url: https://docs.callsign.com/
- type: APIReference
  url: https://docs.callsign.com/
- type: Authentication
  url: https://docs.callsign.com/auth
- type: Support
  url: https://support.callsign.com
- type: Blog
  url: https://www.callsign.com/news
- type: TermsOfService
  url: https://www.callsign.com/terms-of-use
- type: PrivacyPolicy
  url: https://www.callsign.com/privacy-notice
- type: Compliance
  url: https://www.callsign.com/security-and-compliance
- type: TrustCenter
  url: security/callsign-trust-center.yml
- type: Security
  url: security/callsign-vulnerability-disclosure.yml
- type: VulnerabilityDisclosure
  url: security/callsign-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/callsign-domain-security.yml
- type: SecurityTxt
  url: well-known/callsign-security.txt
- type: WellKnown
  url: well-known/callsign-well-known.yml
- type: LLMsTxt
  url: llms/callsign-llms.txt
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence