Numbers Online — phone intelligence

online.numbersPublished by numbers.onlineOfficial publisherv1.0.0Updated Oct 24, 2026

Read-only phone intelligence for AI voice agents — line type, risk, DNC, signed receipts.

VerifiedStreamable HTTPWeb executableCommunication & Collaboration Security & Monitoring

Server details

Identifier: online.numbers/numbers-online
Transport: Streamable HTTP
Runtime: Web executable
Trust: Verified
Published: Sep 16, 2026

Security note

MCP servers receive tool arguments from a conversation and may perform external actions. Review what a server can do before you enable it, and give it only the access it needs.

The registry verified that this server's namespace belongs to numbers.online, which also runs its endpoint. That identifies the publisher; it does not make the server's tools safe.

SourceWeft's checks cover whether the listing is complete and the endpoint answered; they do not review the server's code or what its tools do.

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Overview

AI-generated overview

Hosted read-only MCP server giving AI voice agents phone-number intelligence: line type, spam risk, first-party DNC signals and signed receipts.

What you can do: Look up a full phone-number bundle: validity, formatting, line type, range carrier, country, caller name, STIR/SHAKEN verstat, spam signal, DNC signal and a signed receipt
Classify a number deterministically and free of charge: validity, line type, carrier, country and formatting
Read a labeled risk signal for an inbound caller, with verstat passthrough and a first-party do-not-contact signal, without a name dip
Check a first-party do-not-contact preference (suppress, no match or unknown) for a number
Retrieve and verify signed receipts for billable answers
When to use it: Useful when building or operating an AI voice agent that needs to screen inbound callers or sanity-check outbound numbers before spending agent minutes. It suits teams that want a quick, hosted enrichment step rather than running their own telephony data pipeline.
Requirements: Remote Streamable HTTP endpoint; nothing to install. Tool calls need an API key with the mcp use case, sent as an Authorization Bearer header; discovery (initialize, ping, tools/list) works without auth. Network access to the hosted service.

Before you install

The full bundle is metered and billed per call; line_type and dnc_check are free. Outputs are advisory, low-confidence signals, not compliance verdicts, and the DNC signal is first-party only, not a government registry. Receipt IDs act as capabilities and should be treated as sensitive because the number hash can be matched to a candidate number. Raw numbers are hashed rather than stored.

Installation

In SourceWeft

Open Numbers Online — phone intelligence in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/online.numbers%2Fnumbers-online/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "numbers-online-phone-intelligence": {
      "type": "http",
      "url": "https://numbers.online/api/v1/mcp"
    }
  }
}

README

Numbers Online — phone-intelligence MCP server

A hosted, read-only Model Context Protocol server that gives an AI voice agent phone intelligence in a single call: who is this inbound caller, and is this outbound number one to think twice about dialing — before it burns agent minutes.

Endpoint: POST https://numbers.online/api/v1/mcp (Streamable HTTP, JSON-RPC 2.0)
Transport: remote / hosted — nothing to install or run. Point your agent at the URL.
Auth: Authorization: Bearer <api_key> for tool calls; discovery is public.
Docs: https://numbers.online/docs/integrations · Site: https://numbers.online

Positioning. Every output is an advisory, low-confidence supplementary signal. The calling agent keeps every routing and dialing decision and remains responsible for compliance. Nothing here asserts that a call is lawful, unlawful, "safe", or "spam".

Tools

Four read-only tools (all annotated readOnlyHint, idempotentHint). Discover them live with tools/list (no auth required).

Tool	Returns	Billed
`phone_lookup`	Full bundle — validity, formatting, line type, range carrier, country, caller name (CNAM where available), STIR/SHAKEN verstat, a labeled spam signal, first-party DNC signal, signed receipt	bundled per-call
`caller_risk`	Spam signal + verstat + first-party DNC signal + receipt (no name dip)	bundled per-call
`line_type`	Deterministic only — validity, line type (mobile / fixed line / VoIP / …), carrier, country, formatting	free
`dnc_check`	First-party do-not-contact signal + signed receipt	free

About the DNC signal

The DNC signal is first-party, consent-first: it reflects a do-not-contact preference registered and verified by the number's own owner inside Numbers Online. It is not a copy, mirror, or replica of any government or licensed do-not-call registry. The values:

SUPPRESS — the owner registered a do-not-contact preference for this channel.
NO_MATCH — no suppression preference on record (absence of suppression is not consent).
UNKNOWN — the number couldn't be evaluated.

Treat it as a supplementary input to your own TCPA process, never a verdict that a call is lawful. (Reassigned-number status is inherently a carrier/FCC dataset and is intentionally not offered as a first-party signal — there's no reassigned_check tool.)

Connect

Any MCP client (Claude Desktop, Claude Code, IDEs)

Add a remote server pointing at the endpoint. Example mcp.json fragment:

json

{  "mcpServers": {    "numbers-online": {      "type": "streamable-http",      "url": "https://numbers.online/api/v1/mcp",      "headers": { "Authorization": "Bearer YOUR_API_KEY" }    }  }}

{  "mcpServers": {    "numbers-online": {      "type": "streamable-http",      "url": "https://numbers.online/api/v1/mcp",      "headers": { "Authorization": "Bearer YOUR_API_KEY" }    }  }}

A key needs the mcp use case. initialize, ping, and tools/list work without auth (capability discovery); tools/call is fail-closed and requires the key.

Vapi

Register Numbers Online as an MCP tool — the transport literal is shttp (see integrations/mcp/vapi-mcp-tool.json). A Vapi custom-function-tool alternative lives at integrations/vapi/numbers-online-tool.json.

Retell

Point your agent's call_inbound webhook at the drop-in config in integrations/retell/inbound-webhook.json. It always returns HTTP 200 within Retell's budget (fail-open) so a slow lookup never keeps the caller ringing.

Full walkthrough: docs/ai-voice-agents.md.

Quick smoke test

bash

# discover tools (no auth)curl -s https://numbers.online/api/v1/mcp \  -H 'content-type: application/json' \  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
# call a tool (needs an mcp-scoped key)curl -s https://numbers.online/api/v1/mcp \  -H "Authorization: Bearer $KEY" -H 'content-type: application/json' \  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"phone_lookup","arguments":{"number":"+14155552671"}}}'

# discover tools (no auth)curl -s https://numbers.online/api/v1/mcp \  -H 'content-type: application/json' \  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
# call a tool (needs an mcp-scoped key)curl -s https://numbers.online/api/v1/mcp \  -H "Authorization: Bearer $KEY" -H 'content-type: application/json' \  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"phone_lookup","arguments":{"number":"+14155552671"}}}'

Runnable reference clients (zero-dependency) are in examples/ — Node and Python.

Signed receipts (verifiable "checked as of T" evidence)

Every billable answer can carry a receipt_id and an Ed25519 response_signature. Fetch the receipt later — no API key required, the id is the capability:

No raw phone number is stored — only number_hash = sha256(E.164). Verify with the public key at GET https://numbers.online/api/v1/publickey. A receipt is verifiable evidence that a status was checked at a point in time — not proof that dialing was lawful. Treat a receipt id as sensitive (a phone number is a small keyspace, so the hash is bindable to a candidate number).

Privacy

Raw phone numbers are never logged or stored; they are hashed (sha256). The MCP path is read-only and stateless. Privacy policy: https://numbers.online/privacy

Pricing

The full bundle is metered as one bundled per-call dip (validation + line type + risk + first-party DNC in a single call). line_type and dnc_check are free. See https://numbers.online for current rates.

Developer: Evergrow · Product: Numbers Online · Contact: [email protected] · License: MIT

Source: README.md at commit 3d9cec4

Tools

phone_lookup

Phone number intelligence

Return a supplementary, low-confidence intelligence bundle for a phone number: validity, formatting, line type, range carrier, country, caller name (CNAM, where available), STIR/SHAKEN verstat (supply the call's verstat to fold it into the spam signal), a labeled spam signal, and a first-party do-not-contact (DNC) signal — a suppression preference registered by the number's own owner, never a copy of any government registry. Advisory only — the agent keeps every routing and dialing decision.

Parametersnumberrequiredverstatmax_cache_age_seconds

line_type

Line type

Return only the deterministic fields for a number — validity, line type (mobile / fixed line / VoIP / …), range carrier, country, and formatting. No paid dip; a free, fast classification a voice agent can call before deciding to enrich.

Parametersnumberrequired

caller_risk

Caller risk signal

Return a labeled, low-confidence risk read for an inbound caller: a spam signal (0–100, higher = riskier), verstat passthrough, and a first-party do-not-contact (DNC) signal — without a name dip. A supplementary input to the agent's own policy, never a verdict on whether to accept or reject the call. Supply the call's STIR/SHAKEN verstat to fold it into the signal — a failed validation raises the risk.

Parametersnumberrequiredverstat

dnc_check

Do-not-contact supplementary signal

Return a first-party do-not-contact signal (suppress / no_match / unknown) for a number, sourced ONLY from suppression preferences registered and verified by the number's own owner inside Numbers Online — never a copy of any government or licensed do-not-call registry. "suppress" = the owner asked not to be contacted on this channel; "no_match" = no suppression preference on record (absence of suppress is not consent); "unknown" = the number could not be evaluated. Comes with a signed receipt recording the status "as of T". Advisory input to the agent's own process — it does not assert that a call is lawful.

Parametersnumberrequired

Version history

v1.0.0LatestSep 16, 2026

Score

100% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.