aid: numbers-online
name: Numbers Online
description: 'Numbers Online is a phone-number trust and intelligence service operated by Evergrow Management Pte.
  Ltd. of Singapore. It runs a free public reverse phone lookup with a community-driven, advisory spam-risk score,
  paid number verification for people and businesses, and a B2B API keyed on a single E.164 primitive: parsing and
  validation, single and batch lookup (line type, range carrier, CNAM, STIR/SHAKEN verstat and a low-confidence
  spam signal), signed inbound caller intelligence with Ed25519 receipts, an outbound pre-call do-not-contact scrub
  and call-provenance enrollment, consent-first list scrubbing, a ClearIP-compatible SBC/SIP redirect decision,
  a multi-tenant MSP control plane, and a hosted read-only MCP server plus Vapi/Retell webhooks for AI voice agents.
  The 56-operation REST API is published as an OpenAPI 3.0.3 contract at /api/spec, with an llms.txt, an A2A agent
  card at /.well-known/agent-card.json, markdown mirrors of the docs, and a self-service free tier with no card.'
image: https://numbers.online/android-chrome-512x512.png
url: https://raw.githubusercontent.com/api-evangelist/numbers-online/refs/heads/main/apis.yml
x-type: company
x-source: harvest:a2a-registry
x-tier: enriched
x-tier-reason: harvest
specificationVersion: '0.20'
created: '2026-09-19'
modified: '2026-09-19'
tags:
- Phone Intelligence
- Caller ID
- CNAM
- Reverse Phone Lookup
- Spam Detection
- Do Not Call
- Telephony
- STIR/SHAKEN
- MCP
- agent-native
- Compliance
- Company
apis:
- aid: numbers-online:numbers-online-phone-intelligence-api
  name: Numbers Online Phone Intelligence API
  description: 'One REST API over a single E.164 primitive: parse and validate numbers, single and bulk lookup (line
    type, range carrier, CNAM, STIR/SHAKEN verstat and a supplementary spam signal), signed inbound caller intelligence
    with single-use receipts, outbound pre-call do-not-contact scrub and call-provenance enrollment, consent-first
    list scrubbing, prepaid accounts and key lifecycle, a ClearIP-compatible SBC/SIP redirect decision, operator
    HMAC signing, a signed FCC robocall-mitigation evidence bundle, and a multi-tenant MSP control plane. Keys are
    self-service (POST /api/v1/account/signup), sent as X-API-Key or Authorization: Bearer; the free tier is rate-limited
    and unbilled, the standard tier is prepaid per dip.'
  image: https://numbers.online/android-chrome-512x512.png
  humanURL: https://numbers.online/docs
  baseURL: https://numbers.online
  tags:
  - Phone Intelligence
  - Caller ID
  - CNAM
  - Do Not Call
  - Telephony
  properties:
  - type: OpenAPI
    url: openapi/numbers-online-openapi.yml
  - type: OpenAPI
    name: Provider-hosted OpenAPI 3.0.3 (source of truth)
    url: https://numbers.online/api/spec
  - type: Documentation
    url: https://numbers.online/docs
  - type: APIReference
    url: https://numbers.online/docs
  - type: GettingStarted
    url: https://numbers.online/developers
  - type: Guides
    url: https://numbers.online/docs/integrations
  - type: Authentication
    url: authentication/numbers-online-authentication.yml
  - type: Conventions
    url: conventions/numbers-online-conventions.yml
  - type: Idempotency
    url: conventions/numbers-online-conventions.yml
  - type: ErrorCatalog
    url: errors/numbers-online-problem-types.yml
  - type: RateLimits
    url: rate-limits/numbers-online-rate-limits.yml
  - type: Plans
    url: plans/numbers-online-plans-pricing.yml
  - type: Lifecycle
    url: lifecycle/numbers-online-lifecycle.yml
  - type: ChangeLog
    url: changelog/numbers-online-changelog.yml
  - type: DataModel
    url: data-model/numbers-online-data-model.yml
  - type: Conformance
    url: conformance/numbers-online-conformance.yml
  - type: Overlay
    url: overlays/numbers-online-openapi-overlay.yaml
  - type: AgenticAccess
    url: agentic-access/numbers-online-agentic-access.yml
  - type: LLMsTxt
    url: https://numbers.online/llms.txt
  - type: AgentSkill
    url: skills/_index.yml
  - type: Pricing
    url: https://numbers.online/pricing
  - type: SignUp
    url: https://numbers.online/developers
- aid: numbers-online:numbers-online-mcp-server
  name: Numbers Online MCP Server
  description: A hosted, stateless, read-only Model Context Protocol server (JSON-RPC 2.0 over Streamable HTTP,
    protocol 2025-06-18) at POST https://numbers.online/api/v1/mcp for AI voice agents (Vapi, Retell, Pipecat, LiveKit).
    initialize, ping and tools/list are public; tools/call requires an API key with the mcp use case. Live tools/list
    returns phone_lookup, line_type, caller_risk and dnc_check, each annotated readOnlyHint/idempotentHint. Every
    output is a supplementary, low-confidence signal; the calling agent keeps every routing and dialing decision.
    Billed $0.015 per tool call on the standard tier.
  image: https://numbers.online/android-chrome-512x512.png
  humanURL: https://numbers.online/docs/integrations/ai-voice-agents-mcp
  baseURL: https://numbers.online/api/v1/mcp
  tags:
  - MCP
  - agent-native
  - Phone Intelligence
  properties:
  - type: MCPServer
    url: mcp/numbers-online-mcp.yml
  - type: MCPServer
    url: https://numbers.online/api/v1/mcp
  - type: Documentation
    url: https://numbers.online/docs/integrations/ai-voice-agents-mcp
  - type: ToolCrosswalk
    url: mcp/numbers-online-tool-crosswalk.yml
  - type: GitHubRepository
    url: https://github.com/numbers-online/numbers-online-mcp
  - type: Authentication
    url: authentication/numbers-online-authentication.yml
  - type: AgentCard
    url: a2a/numbers-online-a2a.yml
  - type: RateLimits
    url: rate-limits/numbers-online-rate-limits.yml
  - type: Plans
    url: plans/numbers-online-plans-pricing.yml
- aid: numbers-online:numbers-online-a2a-agent
  name: Numbers Online A2A Agent
  description: An Agent-to-Agent (A2A protocolVersion 0.3.0, JSONRPC) endpoint at POST https://numbers.online/api/v1/a2a
    exposing four read-only skills — phone_lookup, line_type, caller_risk and dnc_check — the same capabilities
    as the MCP tools. Discovered via the provider-served agent card at /.well-known/agent-card.json (also /.well-known/agent.json
    and /api/agent-card). Bearer API key with the mcp use case; anonymous message/send returns 401 missing_key and
    GET returns 405. This endpoint is not described in the OpenAPI.
  image: https://numbers.online/android-chrome-512x512.png
  humanURL: https://numbers.online/docs
  baseURL: https://numbers.online/api/v1/a2a
  tags:
  - A2A
  - agent-native
  - Phone Intelligence
  properties:
  - type: AgentCard
    url: a2a/numbers-online-a2a.yml
  - type: AgentCard
    url: https://numbers.online/.well-known/agent-card.json
  - type: Documentation
    url: https://numbers.online/docs
  - type: ToolCrosswalk
    url: mcp/numbers-online-tool-crosswalk.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://numbers.online/
- type: DomainSecurity
  url: security/numbers-online-domain-security.yml
- type: AgenticAccess
  url: agentic-access/numbers-online-agentic-access.yml
- type: Authentication
  url: authentication/numbers-online-authentication.yml
- type: DeveloperPortal
  url: https://numbers.online/developers
- type: Documentation
  url: https://numbers.online/docs
- type: APIReference
  url: https://numbers.online/docs
- type: GettingStarted
  url: https://numbers.online/developers
- type: Pricing
  url: https://numbers.online/pricing
- type: SignUp
  url: https://numbers.online/developers
- type: Login
  url: https://numbers.online/login
- type: TermsOfService
  url: https://numbers.online/terms
- type: PrivacyPolicy
  url: https://numbers.online/privacy
- type: About
  url: https://numbers.online/about
- type: Trust
  url: https://numbers.online/trust
- type: GitHubOrganization
  url: https://github.com/numbers-online
- type: LLMsTxt
  url: https://numbers.online/llms.txt
- type: AgentCard
  url: a2a/numbers-online-a2a.yml
- type: AgentCard
  url: https://numbers.online/.well-known/agent-card.json
  name: Provider-served A2A agent card (protocolVersion 0.3.0)
- type: WellKnown
  url: well-known/numbers-online-well-known.yml
- type: LLMsTxt
  url: llms/numbers-online-llms.txt
- type: Packages
  url: packages/numbers-online-packages.yml
- type: Overlay
  url: overlays/numbers-online-openapi-overlay.yaml
- type: Conformance
  url: conformance/numbers-online-conformance.yml
- type: ErrorCatalog
  url: errors/numbers-online-problem-types.yml
- type: Lifecycle
  url: lifecycle/numbers-online-lifecycle.yml
- type: Deprecation
  url: lifecycle/numbers-online-lifecycle.yml
  name: Frozen-permanent-alias deprecation posture, stated in the OpenAPI at /api/spec
- type: Conventions
  url: conventions/numbers-online-conventions.yml
- type: Idempotency
  url: conventions/numbers-online-conventions.yml
  name: Idempotency-Key on lookup, batch lookup, scrub and SBC redirect (at-most-once billing; coverage partial)
- type: RateLimits
  url: rate-limits/numbers-online-rate-limits.yml
- type: Plans
  url: plans/numbers-online-plans-pricing.yml
- type: ChangeLog
  url: changelog/numbers-online-changelog.yml
- type: ChangeLog
  url: https://numbers.online/api/spec
  name: Version changelog table inside the OpenAPI description
- type: DataModel
  url: data-model/numbers-online-data-model.yml
- type: AgentSkill
  url: skills/_index.yml
- type: AgentSkill
  url: skills/numbers-online-inbound-caller-intelligence.md
  name: Assess an inbound caller and file a receipt-backed report
- type: AgentSkill
  url: skills/numbers-online-outbound-precall-scrub.md
  name: Scrub a destination before dialing and enrol your caller ID
- type: AgentSkill
  url: skills/numbers-online-pbx-caller-id.md
  name: Label inbound calls on a PBX or softphone
- type: AgentSkill
  url: skills/numbers-online-key-lifecycle.md
  name: Sign up, fund and rotate API keys safely
- type: AgentSkill
  url: skills/numbers-online-msp-tenants.md
  name: Run multi-tenant customers under one prepaid balance
- type: DataSubjectRequest
  url: https://numbers.online/opt-out
- type: NoticeAndAction
  url: https://numbers.online/opt-out
- type: Guides
  url: https://numbers.online/docs/integrations
- type: AgentInstructions
  url: https://numbers.online/ai-agents
- type: Support
  url: https://numbers.online/concierge
x-enrichment:
  date: '2026-09-19'
  status: enriched
  artifacts_added: 31
  pass: local-v3