# Numbers Online

**Canonical:** https://apis.io/providers/numbers-online/  
**Website:** https://numbers.online/  
**APIs profiled:** 2

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.

## Kin Score — 60.4 / 100 (strong)

Scored 2026-10-09 under rubric 0.23.0. Trend: flat (+0.0 from 60.4).

| Facet | Score |
|---|---|
| Discoverability | 75.0 |
| Contract Quality | 48.5 |
| Contract Governance | 18.2 |
| Operational Transparency | 60.5 |
| Developer Ergonomics | 56.5 |
| Access Clarity | 84.2 |

Regulatory layer — **Horizontal (data, software, accessibility, platform)**: 37.3 (matched via fallback).

## Agent readiness — 49.7 (agent-native)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | documented |
| Auth Clarity | bearer |
| Idempotency | verified |
| Error Semantics | verified |
| OpenAPI Examples | verified |
| Rate Limit Signal | verified |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | conformant |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## APIs (17)

- **Numbers Online MCP Server** — 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 agen...
- **Numbers Online A2A Agent** — 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 a...
- **Numbers Online Account API** — Self-service API account: signup, balance, usage, credit top-ups, and the key lifecycle. Account-management endpoints require an account-level key with the 'manage' use case (ev...
- **Numbers Online Community reporting API** — Key-gated spam/scam reporting — the give-to-get half of the community sensor (receipt-gated, tags-only, lane-scoped supplementary signals)
- **Numbers Online Inbound API** — Inbound caller-intelligence lookup for operators, PBX, and softphones
- **Numbers Online Lookup API** — Number lookup: line type, range carrier, CNAM, verstat, and a supplementary spam signal
- **Numbers Online MCP API** — Model Context Protocol server for AI voice agents (Vapi, Retell, Pipecat, LiveKit): read-only phone-intelligence tools over Streamable HTTP
- **Numbers Online MSP API** — Multi-tenant control plane: per-tenant sub-keys, usage rollups, and suppression lists for MSPs and PBX resellers
- **Numbers Online Outbound API** — Outbound pre-call checks (scrub + call-provenance) and number enrollment for spoofing-defense
- **Numbers Online Parsing API** — Phone number parsing and validation endpoints
- **Numbers Online PBX API** — Plain-text caller-id lookup for header-less PBX integrations (FreeSWITCH mod_cidlookup and similar)
- **Numbers Online Receipts API** — Signed, privacy-safe lookup receipts (Ed25519) — verifiable "checked as of T" evidence
- **Numbers Online Reference API** — Reference data and examples
- **Numbers Online SBC / SIP API** — SIP redirect-server decisions for session border controllers (Kamailio, OpenSIPS, dSIPRouter, Sansay, Oracle/Acme Packet, ProSBC) via the operator-run shim recipe, plus an FCC r...
- **Numbers Online System API** — Operational endpoints (health checks)
- **Numbers Online Trust API** — Contact-suppression preference lookups
- **Numbers Online Webhooks API** — AI-voice-agent webhook adapters (Retell inbound, Vapi custom tool) over the same lookup backend

## MCP servers (1)

- **Numbers Online MCP Server** — Numbers Online operates ONE hosted, stateless, read-only MCP server at POST https://numbers.online/api/v1/mcp (JSON-RPC 2.0 over Streamable HTTP; the provider and Vapi call the ...

## Agentic access (1)

- **Numbers Online Agentic Access** — 56 operations · 35 acting · 3 human-in-the-loop

## Security (2)

- **Numbers Online Authentication** — apiKey/http · 3 schemes
- **Numbers Online Domain Security** — TLSv1.3

## Plans (1)

- **Numbers Online Plans Pricing**

## Tags

Phone Intelligence, Caller ID, CNAM, Reverse Phone Lookup, Spam Detection, Do Not Call, Telephony, STIR/SHAKEN, MCP, Agent-Native, Compliance, Company, A2A

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/numbers-online/). Scores are computed from the provider's own public artifacts under a published rubric.