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AI and buying signals

MCP servers for B2B prospecting: 37 vendors checked (2026)

2026-11-09 · 9 min read · Adam Axelsson, founder of Revexa

Most large B2B data and sales tools now run an official MCP server, so Claude, ChatGPT, Cursor or your own agent can search companies and people, enrich contacts and read buying signals from a chat. Of the 37 vendors we checked, 35 have or had one. Twenty are listed in Claude's connector directory, among them Apollo, ZoomInfo, Clay, Lusha, Crustdata, Crunchbase, Leadfeeder and Seamless. A handful can also send: Apollo, Hunter, Instantly, lemlist, Smartlead and Seamless send email or start sequences, and Gojiberry sends LinkedIn messages. Vibe Prospecting, one of the first prospecting connectors in Claude, shuts down on 2 December 2026.

Updated 9 November 2026. Every row below is checked against the vendor's own documentation, help center or listing on that day, with the source linked. Revexa runs a free MCP server for company-level buying signals and builds Leo, so we are not neutral; Revexa sits in the signals group below, in alphabetical order.

What an MCP server does for prospecting

The Model Context Protocol (MCP) is an open standard that lets an AI assistant call outside tools. Connect a prospecting server, and the assistant can do things it can't do on its own:

  • look up which companies are hiring or raised money this week;
  • find the right people at those companies;
  • verify an email address;
  • in some cases, start a sequence or send a message.

The server decides what the assistant may do. Most are read-only or only write to your own CRM or lists. A few can send, and those are the ones to set up with care.

Contact and company data

Search and enrich companies and people. None of these send messages.

ToolFinds companiesFinds peopleSignalsIn Claude's directoryCost to useSource
ClayYesYesResearch: funding, hiring trends, tech stack, executive changesYes500 free credits on first connect, then plan credits; drafts only, sending needs a custom FunctionClay
CognismYesYesIntent topics, event filtersNo (custom connector)Standard or Pro plans; 1 credit per revealed contactCognism
CoresignalYesYesFunding and job data as filtersNoCredits per call (search 20, email 10)Coresignal
CrustdataYesYesJob postings, headcount, funding, web traffic, LinkedIn postsYesCredits per callCrustdata
FindymailYesYesNoNo"API & MCP access" on all plans; 10 free creditsFindymail
LushaYesYes26 dated signal types, including funding, hiring surges and job changesYesSame credits as the API; "does not send messages or add anyone to sequences"Lusha
ProspeoYesYesNoNo1 credit per search page or emailProspeo
ZoomInfoYesYesIntent, scoops, funding, hiring, executive and job changesYesZoomInfo license; search free, enrichment uses creditsZoomInfo

People Data Labs has no official MCP server that we could find.

Buying signals and intent

Tell you which companies have a reason to talk now.

ToolWhat it watchesIn Claude's directoryCost to useSource
6senseKeyword intent, buying stage, website visitsThe vendor says yes (beta enrollment)Revenue Marketing license6sense
BuiltWithTechnology added and removedNoAPI credits; guest lookups or plans from $295BuiltWith
Common RoomWebsite visits, job changes, intent, product usageYesIncluded in all plans, from $2,500 a month billed yearlyCommon Room
CrunchbaseFunding rounds, acquisitions and predictionsYesAll accounts can connect; data tokens per fieldCrunchbase
DemandbaseAccount intent, buying groups, engagementThe vendor says yesEnabled through your account team; 1 credit per recordDemandbase
HarmonicFunding, net-new companies from saved searchesYes100 requests a day at no cost with a Harmonic accountHarmonic
Leadfeeder (Dealfront)Website visits and ICP fitYesPaid plans with API accessLeadfeeder
Revexa (ours)Swedish companies hiring B2B salespeople, startups hiring sales, the week's B2B funding roundsNo (custom connector)Free, no account or keyRevexa
TheirStackHiring from job posts, technographicsThe vendor says yesAPI credits, plans from $49 a monthTheirStack

Sending and sequences

These can act. Check how each one asks before it sends.

ToolWhat it can doFinds leadsIn Claude's directorySource
AmplemarketLaunches sequences ("starts sending") and enrolls leadsYesNoAmplemarket
ApolloSends one-off emails, adds contacts to sequences; also finds leads by hiring and funding signalsYesYesApollo
GojiberrySends LinkedIn messages, activates campaigns, reads intent signalsYesNoGojiberry
HunterStart-Sequence "begins sending real emails"; finds emails and companies, funding and hiring signalsYesNoHunter
InstantlyCreates and activates campaigns, adds leads, repliesNot confirmedNoInstantly
lemlistStarts campaigns, sends messages and replies, LinkedIn steps; searches a B2B databaseYesNolemlist
OutreachCreates sequences and enrolls prospects; no direct send toolOwn data onlyYesOutreach
Seamless.AISends email and bulk email with confirmation (Connect license); job-change signalsYesYesSeamless
SmartleadSends email "only after you confirm"Not confirmedThe vendor says yesSmartlead
UnifyApproving an enrollment starts sending; finds companies and people through its agentYesYesUnify

Salesloft's listing shows only search tools, and we could not verify sending for Salesforce's beta server.

CRMs and web research

  • CRMs:
    • HubSpot, Salesforce (beta), Attio and Pipedrive have official servers that read and write your own CRM records.
    • They don't find new companies.
    • HubSpot says its Claude connector needs a paid Claude plan.
  • Web research:
    • Exa searches the web for companies and people, with a free tier.
    • Apify runs thousands of scrapers.
    • Bright Data scrapes and searches, with 5,000 free requests a month.
    • None of the three has dedicated signal tools, and none sends.

Closed and closing

  • Vibe Prospecting (Explorium) is available until 2 December 2026. Its MCP server, its app and Explorium's API (AgentSource) close with it. Unused credits are refunded within 30 days, and data is deleted by 31 December. See Vibe Prospecting alternative.
  • Trigify closed on 22 October 2026 after HubSpot hired the team, and its MCP server went with it. See Trigify alternatives.

How to choose

  • To build lists with emails and phone numbers: Apollo, ZoomInfo, Lusha or Crustdata. They are all in Claude's directory and sell on credits.
  • To know who to call this week:
    • Crunchbase or Harmonic for funding;
    • TheirStack for hiring and tech;
    • Leadfeeder for website visits;
    • Common Room, 6sense or Demandbase if you already pay for them.
  • To send from the chat: Apollo, Hunter, lemlist, Instantly, Smartlead or Seamless. Turn on every confirmation the tool offers, and test on your own address first.
  • To start for free:
    • Hunter's free plan (50 credits a month);
    • Harmonic's 100 daily requests;
    • Exa's free tier;
    • Bright Data's 5,000 requests;
    • Revexa's signal server.
  • To have an agent do the whole job: Gojiberry runs signals, messages and campaigns from the chat. Leo by Revexa, ours, does the same in its own app, iMessage and Slack, and asks for your approval before anything is sent; Revexa's MCP server covers only the signals.

Setting one up

  • Claude:
    • Customize → Connectors → + Add → Add custom connector, then enter the server URL.
    • Custom connectors work on every plan, and the Free plan allows one.
    • On Team and Enterprise, an Owner adds them under Organization settings → Connectors.
    • A tool call may take up to 240 seconds.
    • Source: Claude help, checked 9 November 2026.
  • ChatGPT:
    • Go to chatgpt.com/plugins, select +, then Add custom MCP server, and finish with Create as a plugin.
    • Your plan and workspace settings decide whether custom servers are allowed.
    • Source: OpenAI.
  • Claude Code: claude mcp add --transport http <name> <url>, then /mcp to sign in.
  • Cursor: .cursor/mcp.json with { "mcpServers": { "<name>": { "url": "<url>" } } }.

Directory connectors connect in one click. Everything else is added by URL, and some servers need an API key in a request header.

Frequently asked questions

What is the best MCP server for B2B prospecting?

It depends on the job:

  • Contact data in Claude's directory: Apollo, ZoomInfo and Lusha.
  • Buying signals: Crunchbase, Harmonic, TheirStack and Leadfeeder.
  • Sending from the chat: Apollo, lemlist, Instantly, Smartlead and Seamless.

All were checked on 9 November 2026.

Which prospecting MCP servers can send emails or LinkedIn messages?

Email:

  • Apollo (one-off emails and sequences);
  • Hunter (sequences);
  • Instantly and lemlist (campaigns and replies);
  • Smartlead (after you confirm);
  • Seamless (with its Connect license).

LinkedIn messages: Gojiberry.

Sequences: Amplemarket and Unify launch sequences that send.

Is there a free MCP server for B2B leads?

Several have free tiers:

  • Hunter (50 credits a month);
  • Harmonic (100 requests a day with an account);
  • Exa (free tier);
  • Bright Data (5,000 requests a month).

Revexa's server is free with no account. It returns Swedish companies hiring B2B salespeople, startups hiring sales and the week's B2B funding rounds, at company level.

What replaces Vibe Prospecting in Claude?

For contact data in Claude's directory, Apollo, ZoomInfo, Lusha, Crustdata and Clay are the closest. For buying signals, Crunchbase, Harmonic and Leadfeeder. If you used Vibe to build lists that you then contacted, an agent that finds the buyer and writes to them may save the export step. See Vibe Prospecting alternative.

Which ChatGPT plans can add custom MCP servers?

OpenAI's documentation says account and workspace policies decide it. Check your workspace settings, and in Business or Enterprise, ask your admin.