Best B2B data API and MCP server for AI agents

Six B2B data providers offer both an API and an official MCP server an agent can call. Apollo suits buyers who want a large established database, phone numbers and SOC 2 today, with MCP on every plan. Leadsets suits agent builders who want flat monthly pricing, SDKs and honest email labels, but has no phones yet. ZoomInfo, Lusha, Wiza and Clay fit narrower needs.

Facts about other products checked on 2026-11-09 · sources listed below

Product	Best for	Starting price	Pricing model	API / MCP	Phone numbers
Apollo	Large database, phones and SOC 2 today	Free; Basic $59/seat/mo monthly ($49 annual)	Per-seat credits, expire each cycle	REST + `mcp.apollo.io` on every plan	Yes (5 credits)
Leadsets	Agent builders wanting flat cost and SDKs	Free 1,000 records once; Solo $29/mo	Flat monthly, fair-use limits	REST + `mcp.leadsets.ai` on every plan, TS/Python SDKs	Not yet
ZoomInfo (GTM.ai)	Enterprise data depth, usage-based access	Free 1,000 data credits; pay as you go from $20	Data and AI credits, expire after 12 months	REST + `mcp.zoominfo.com`, licence required	Direct dials; mobile on Enterprise
Lusha	Phones and emails with API on every plan	Free 40 credits/mo; Starter $49.90/mo monthly	Credits, 1 charged per request	REST + MCP on every plan	Yes (5 credits)
Wiza	Pay-per-result lookups from LinkedIn URLs	API credits $0.025 each, min $50	Prepaid credits, charged on data returned	REST + `mcp.wiza.co`	Yes (5 credits)
Clay	Visual workflows across many providers	Free; Launch $167/mo annual ($185 monthly)	Data credits plus actions	MCP (plans not published); Tables API Enterprise	Yes, from Launch

How we compared

We checked each vendor's public pages on 2026-11-09 and kept only tools that offer both a public API and an official MCP server an agent can call. All six qualify. Leadsets is our product, so read our placement with that in mind; we have tried to state where others fit better.

We scored fit for one job: an AI agent calling a data source directly, without a human clicking through a dashboard. The criteria:

Agent access. An official remote MCP server and a REST API, and which plans include them. If you are new to the protocol, see what an MCP server is.
Cost behaviour in loops. Agents retry, paginate and hit empty results. We looked at what is charged, whether misses cost anything and whether credits expire.
Coverage. Vendor-stated database size and whether phone numbers are available.
Verification transparency. Whether uncertain emails are labelled separately from valid ones.
Developer tooling. SDKs, published rate limits and retry support.
Compliance today. SOC 2 and GDPR status as stated by each vendor.

The order below reflects fit for this category, not overall product quality.

The shortlist, in order of fit

1. Apollo

Apollo offers an official remote MCP server at mcp.apollo.io and native connectors in Claude, ChatGPT and Perplexity on any plan, including Free, at no extra cost. Its MCP can search and enrich people and companies, create contacts, build sequences and report on campaigns. Apollo publishes API rate limits (for example 200 requests a minute on general endpoints and 1,000 on enrichment for paid plans) and has an official CLI with an agent skill. Apollo says it has 240M+ contacts and 30M+ companies, sells phone numbers (5 credits each) and is SOC 2 Type II and ISO 27001 certified. It ranks first because it covers the widest set of criteria today. Trade-offs: pricing is per seat, unused credits expire each cycle, plan access to the API is stated inconsistently on its own pages, and no language SDKs are published.

2. Leadsets

Leadsets is built as an agent data source first: a remote MCP server at mcp.leadsets.ai with eight tools, the same tools over REST, and TypeScript and Python SDKs with idempotency keys and Retry-After headers. Paid plans are flat monthly prices (Solo $29, Pro $99, Team $399, Max $999) with no credits, and records count only when data comes back. Every email is labelled verified, catch-all, unknown or invalid, and get_usage lets the agent check remaining limits for free. It also includes company website and careers page scraping as a units add-on. It sits below Apollo because it has no phone numbers yet, SOC 2 Type I is planned with a Q3 2027 target rather than done, and it does not publish a headline record count.

3. ZoomInfo (GTM.ai)

ZoomInfo runs an official MCP server at mcp.zoominfo.com for Claude, ChatGPT, Perplexity, Cursor, Codex and VS Code Copilot, plus an API and CLI sold through GTM.ai. GTM.ai Free gives 1,000 data credits and 1,000 AI credits at signup with no card, expiring after 12 months; pay as you go data credits are $0.38 each at the $1,000 spend tier. ZoomInfo says it has 410M+ contact profiles and 135M+ direct dial numbers, and lists ISO 27001, ISO 27017, ISO 27701 and an AICPA SOC report. It places third because MCP requires a licence, rate limits are not published, mobile data is Enterprise only and main platform pricing is not published.

4. Lusha

Lusha's MCP server connects over OAuth with guides for Claude, ChatGPT, n8n and Cursor, and an API key is available on every plan including Free. It sells phones (5 credits) and emails (1 credit), claims SOC 2 Type II and several ISO certifications, and says it has 515M+ verified contacts. For agents, two details matter: a minimum of 1 credit is charged per request even when no data comes back, and Free and Starter keys are limited to 100 requests a day.

5. Wiza

Wiza offers an official remote MCP server at mcp.wiza.co (OAuth or API key) for ChatGPT, Claude and Codex. Prepaid API credits cost $0.025 each with a 2,000-credit minimum, and Wiza says they are deducted only when data is returned. It sells phones and says it has 850M+ contacts. It places fifth because its subscription pricing lists API access on the Team plan, with one-off credits as the self-serve route, and emails are labelled only valid or risky.

6. Clay

Clay has an official MCP for Claude, ChatGPT and Codex that exposes its data providers and research agents, though plan availability is not published. Clay says it aggregates 50+ built-in providers through waterfalls. It is a strong fit if you want a visual table and workflow builder, but as a directly called API it is thinner: the Tables API is Enterprise only and rate limits are not published.

Which tool suits which buyer

You need phone numbers or SOC 2 today: Apollo, Lusha or ZoomInfo. Leadsets is not a fit here yet.
You want predictable cost for high-volume agent runs: Leadsets, with flat plans and visible limits. See plans and limits.
You already run ZoomInfo or need its depth: GTM.ai gives agents usage-based access without seat fees.
You enrich from LinkedIn URLs occasionally: Wiza's prepaid credits suit low, irregular volume.
You want a visual builder and many providers in one place: Clay.

For a side-by-side with the top placement, read Leadsets vs Apollo.

Example: an agent run with misses

Maya Chen at Northwind Analytics asks Claude to find heads of RevOps at 300 companies that look like Stackfold and Parcelry. The agent probes filters, paginates and enriches. Suppose 60 lookups return nothing.

On Lusha, each of those 60 requests still costs at least 1 credit.
On Leadsets, the 60 misses use no records but count as requests, which are capped at five times the record allowance.
Wiza and Clay both say they do not charge when no result comes back.

The agent then verifies emails. A catch-all address is not a confirmed mailbox; see what a catch-all email is. Leadsets returns it labelled catch-all so Maya can send at lower volume. Wiza would label it risky. Check how your chosen tool reports these before an agent sends to them.

What to check before you connect one

Plan access. Confirm MCP and API are on the plan you will buy, not only on trial or Enterprise.
Rate limits and retries. Agents need predictable 429 behaviour. Leadsets documents this in its MCP setup guide and limits docs.
Credit expiry. Apollo credits expire each cycle; GTM.ai credits after 12 months.
Compliance evidence. Ask for SOC 2 reports where needed. Leadsets publishes its current status on its compliance page.

Questions and answers

What is a B2B data MCP server?

It is a Model Context Protocol server that exposes B2B data tools, such as people search, enrichment and email verification, to an AI agent. The agent calls the tools directly from Claude, ChatGPT, Cursor or another MCP client instead of a person exporting lists from a dashboard.

Which B2B data providers have an official MCP server?

As of 2026-11-09, Apollo, Leadsets, ZoomInfo, Lusha, Wiza and Clay each publish an official MCP server. Plan availability differs: Apollo and Leadsets include MCP on every plan, ZoomInfo requires a GTM.ai or Enterprise licence, and Clay does not publish which plans include it.

Which B2B data API for agents includes phone numbers?

Apollo, Lusha and Wiza sell phone numbers, each at 5 credits per number by their own pricing. ZoomInfo says it has 135M+ direct dials, with mobile data on GTM.ai Enterprise, and Clay offers phone enrichment from its Launch plan. Leadsets does not offer phone numbers yet.

Is there a B2B data API for AI agents without credits?

Leadsets charges flat monthly prices (Solo $29, Pro $99, Team $399, Max $999) with no credits, using fair-use limits per five hours and per week. The other tools in this comparison use credits, actions or per-seat allowances.

Do empty results cost credits in agent workflows?

It depends on the vendor. Lusha charges a minimum of 1 credit per request even with no data, while Wiza and Clay say nothing is charged when no result comes back. Leadsets counts records only when data returns, though every call counts toward a separate request limit.

Which B2B data APIs are SOC 2 certified?

Apollo, Lusha, Wiza and Clay each state SOC 2 Type II or Type 2, and ZoomInfo lists an AICPA SOC report and ISO certifications. Leadsets is not SOC 2 certified yet; Type I readiness is underway with a target of Q3 2027.

Sources · checked 2026-11-09

Prices and features change. If something here is out of date, email support@leadsets.ai and we'll fix it.

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