The best MCP server for sales depends on what your agent should change. OXYGEN puts tables, enrichment, sequences across email, LinkedIn and WhatsApp, a CRM and workflows behind one server, with approvals, credit ceilings and free dry runs, from $49 a month. Apollo and lemlist create sequences and send email, HubSpot, Attio and Salesforce update CRM records, ZoomInfo reads its data, and Instantly runs cold email campaigns.
By Tim Scheuer, Co-founder of Oxygen · Checked October 18, 2026
An MCP server lets an AI agent such as Claude Code, Codex, Cursor or Claude call a sales tool directly: search contacts, enrich a list, update a deal, enroll leads in a sequence. The servers below differ in five ways: how you sign in (OAuth, an API key in a header, or a key inside the URL as on Instantly, HeyReach and Smartlead), which coding agents the vendor documents, what the agent can write, which plan you need, and what each call costs. They also differ in reach. CRM servers write records but run no outreach, ZoomInfo reads data and writes no records, and Apollo, lemlist and Instantly create and start campaigns.
| Tool | Endpoint and sign-in | Claude Code, Codex, Cursor | What an agent can write | Plan needed | Cost per call | Starts at |
|---|---|---|---|---|---|---|
 OXYGENAgentic marketing and sales platform | oxygen-agent.com/mcp; OAuth, or a CLI key for clients without OAuth | Claude Code and Codex: CLI with skills, or MCP; Cursor: the CLI | Tables, enrichment, sequences on email, LinkedIn and WhatsApp, CRM records, workflows | Free plan connects; sending needs a paid plan | Previews and dry runs free; paid steps on credits, under your ceiling | Free plan; paid from $49 a month |
 Apollo.ioContact database with a hosted MCP server | mcp.apollo.io/mcp; OAuth, or a master API key in a header | All three documented | Contacts, accounts, deals, lists, sequences and one-off emails | Any plan; search and enrichment need a work email | Plan credits for enrichment and company search; people search free | Any plan, the Free plan included; no MCP fee |
 lemlistMultichannel sequencer with a hosted MCP server | app.lemlist.com/mcp; OAuth, or an API key in a header | All three documented | Campaigns, steps, leads, contacts, messages and replies, mailboxes | Any paid plan | Enrichment spends lemlist credits; cost per action not stated | Paid plans only: Email $69 a month, Multichannel $109 |
 HubSpotCRM with a remote MCP server | mcp.hubspot.com; OAuth 2.1 with PKCE | None named; any OAuth client with PKCE | Contacts, companies, deals, tickets, activities; marketing content | All accounts; some tools need Pro or Enterprise | No credits; up to 200 search results a page | Every HubSpot account; some tools need Pro or Enterprise |
 AttioCRM with a hosted MCP server | mcp.attio.com/mcp; OAuth only, no API keys | Cursor named; Claude Code and Codex not documented | Records, lists, notes, tasks and comments; no email send | All plans | No credits; reads 100 and writes 25 requests a second | Every plan; the SQL tool not on every plan |
 ZoomInfoB2B data provider with a hosted MCP server | mcp.zoominfo.com/mcp; OAuth, each user signs in | All three documented, with plugins for Claude Code and Codex | Its own GTM Context settings only; no CRM or record writes | A ZoomInfo license | Searches free; 1 bulk data credit per new record enriched | Included with a ZoomInfo license; no MCP surcharge |
 InstantlyCold email platform with a hosted MCP server | mcp.instantly.ai/mcp; API key in a header or in the URL | Cursor documented; Claude Code and Codex not | Campaigns, leads, replies, sending accounts and warm-up | A plan with API access, on all Outbound plans | No MCP fee; no credit cost per call stated | Free with a plan that has API access; plans from $47 a month |
 Salesforce Hosted MCPCRM with hosted MCP servers | api.salesforce.com/platform/mcp/v1, one URL per server; per-user OAuth | Cursor documented; Claude Code and Codex not | Records the user can edit; deletes on a separate server | Enterprise Edition or above, or Developer Edition | Each tool call uses API calls from the daily quota | Enterprise Edition or above; no separate MCP price published |
OXYGEN Agentic marketing and sales platformBest for: GTM teams whose agent should build lists, enrich them, run sequences on email, LinkedIn and WhatsApp, and update a CRM in one workspace.
OXYGEN runs one hosted MCP server at oxygen-agent.com/mcp over one workspace: tables, enrichment waterfalls across 17 email providers, sequences that mix email, LinkedIn and WhatsApp, a CRM with a deals pipeline, and workflows. Previews and dry runs are free. Paid steps, sequence launches and CRM syncs ask for approval and stop at a credit ceiling you set. In Claude Code and Codex the oxygen CLI with its skills is the main route, and Codex connects to MCP with ?toolset=core.
Apollo.io Contact database with a hosted MCP serverBest for: Teams that want contact data, CRM records and sequences behind one server, with all three coding agents documented.
Apollo's hosted MCP server at mcp.apollo.io/mcp signs in with OAuth, and headless clients can send a master API key in a header; scoped keys are rejected. Its docs cover Claude, Claude Code, Codex, Cursor, ChatGPT and Perplexity. An agent can search people and companies, enrich them on credits, create contacts, accounts and deals, create sequences, add contacts to them and send one-off emails. There are no destructive tools such as bulk delete, and the connection costs nothing extra on any plan.
lemlist Multichannel sequencer with a hosted MCP serverBest for: Teams that run outreach in lemlist and want the agent to build, start and pause campaigns there.
lemlist hosts its server at app.lemlist.com/mcp, with OAuth or an API key in a header, and an optional ?bucket= filter that trims the tools it advertises. Its setup docs cover Claude Code, Codex, Cursor, Claude, ChatGPT and Grok. An agent can create campaigns, edit sequence steps, start or pause them, add and enrich leads, search a database of 450M+ leads, send messages and replies, and buy domains and mailboxes. Tools that send, delete, spend credits or change campaigns ask for confirmation first.
HubSpot CRM with a remote MCP serverBest for: Teams on the HubSpot CRM that want the agent to read and update contacts, companies and deals directly.
HubSpot's remote MCP server at mcp.hubspot.com has been generally available to all HubSpot accounts since April 2026. It signs in with OAuth 2.1 and PKCE, and custom clients need an MCP connector app on the new developer platform. Agents create and update contacts, companies, deals, tickets, line items, products and activities, query CRM data in an SQL style, and manage segments, pipelines, marketing emails and pages. Actions follow the user's permissions, and write tools generally ask for confirmation.
Attio CRM with a hosted MCP serverBest for: Teams on Attio that want the agent to search records, notes and calls and keep the CRM current.
Attio's server at mcp.attio.com/mcp signs in with OAuth only, with no API keys, and acts as the user with their workspace permissions. Its 48 tools search and read records, lists, notes, meetings, call recordings and emails, run reports and read-only SQL, and create or update records, list entries, notes, tasks and comments. Reads run without asking, writes ask for confirmation in most clients, and the server cannot send email or delete records. It is available on every plan.
ZoomInfo B2B data provider with a hosted MCP serverBest for: Teams with a ZoomInfo license that want its contacts, intent and account research inside the agent.
ZoomInfo's server at mcp.zoominfo.com/mcp signs each user in with OAuth, through ZoomInfo credentials or SSO, and scopes every call to that user. Its docs cover Claude, Claude Code and Codex through plugins or an add command, Cursor, ChatGPT and others. An agent searches companies, contacts, intent and scoops for free, enriches up to 25 records a call on bulk data credits, and runs account research on AI action credits. It writes no CRM or ZoomInfo records; write-back goes through the ZoomInfo API.
Instantly Cold email platform with a hosted MCP serverBest for: Teams that send cold email from Instantly and want the agent to run campaigns, leads and replies there.
Instantly's server at mcp.instantly.ai/mcp signs in with an API v2 key only: in a header, which it recommends, or inside the URL path. Its quickstart covers Claude Desktop, Cursor and n8n; Claude Code, Codex and ChatGPT have no steps. Each tool maps to an API v2 endpoint, so an agent can create, pause and activate campaigns, add and move leads, reply to and forward emails, verify emails, and manage sending accounts and warm-up. It comes free with a subscription that has API access.
Instantly website · Oxygen vs Instantly: the full comparison
Salesforce Hosted MCP CRM with hosted MCP serversBest for: Teams on Salesforce Enterprise Edition that want the agent to query and update records with each user's own access.
Salesforce runs hosted MCP servers for Enterprise Edition and above, plus Developer Edition, at api.salesforce.com/platform/mcp/v1, with one URL per server. Each user signs in with OAuth and PKCE through an External Client App, and the agent inherits that user's object, field and sharing access. Standard servers read records, create and update them, or delete them, and admins can build custom servers from Apex actions, Flows and named queries. Every server starts disabled until an admin turns it on.
| If you need | Pick |
|---|---|
| One server for data, sequences, CRM and workflows, under approvals and credit ceilings | OXYGEN |
| Contact data, sequences and one-off emails from one server | Apollo.io |
| An agent that builds and starts lemlist campaigns | lemlist |
| Read and update the HubSpot CRM from the agent | HubSpot |
| Search and update Attio records, notes and call recordings | Attio |
| ZoomInfo contacts, intent and research, read-only | ZoomInfo |
| Salesforce records, with each user's own access | Salesforce Hosted MCP |
An MCP server is a vendor's endpoint that an AI agent connects to through the Model Context Protocol. For sales, it turns the tool's actions into calls the agent can make: search people, enrich a list, update a deal, enroll leads in a sequence. Most sales vendors host theirs at a URL, and you sign in with OAuth or an API key.
Add the server's URL in the client and sign in: claude mcp add --transport http in Claude Code, codex mcp add in Codex, or the MCP settings in Cursor. Apollo, lemlist and ZoomInfo document all three. For OXYGEN, the main route in Claude Code and Codex is the oxygen CLI with its skills; Codex connects to MCP with ?toolset=core, and in Cursor the tested route is the CLI in the terminal.
Yes, on some servers. Apollo's sends one-off emails and adds contacts to sequences, lemlist's starts campaigns and sends messages and replies after a confirmation, and Instantly's replies to and forwards emails. OXYGEN enrolls leads into sequences that mix email, LinkedIn and WhatsApp; enrolling never sends, and starting needs an approval and a cap on live sends. Attio's server sends no email, and ZoomInfo's writes no records.
It depends on the server. lemlist asks before tools that send, delete, spend credits or change campaigns, Attio asks before writes in most clients, and Instantly documents no server-side approval. ZoomInfo admins can set credit limits per user. In OXYGEN, previews and dry runs are free, and paid runs, sequence launches and CRM syncs need an approval with a credit ceiling; a run that hits the ceiling skips the remaining items instead of spending more.
MCP suits chat clients and quick lookups, because the client lists the tools and handles sign-in. A CLI suits coding agents doing longer jobs in a terminal: it imports large files, runs in scripts and CI, and comes with skills that teach the agent its commands. OXYGEN offers both, and its docs make the CLI the main route for Claude Code and Codex; large files go through the CLI, not through MCP prompts.
A key inside the URL can end up in logs, shell history and shared config files. Instantly accepts one in the URL path and recommends a header instead, and HeyReach and Smartlead put the key in the connection URL. OXYGEN, Apollo, lemlist, HubSpot, Attio, ZoomInfo and Salesforce sign users in with OAuth through the browser, so no key sits in a config file. If you must use a key, send it in a header with the narrowest scope the vendor allows.
HubSpot and Salesforce run their own servers: HubSpot's at mcp.hubspot.com for every account, and Salesforce's hosted servers for Enterprise Edition and above. OXYGEN's server works on its own CRM, which syncs both ways with HubSpot. It has no Salesforce sync, so a Salesforce team should connect Salesforce's own server for CRM records.
We make OXYGEN, so it comes first and you should read this as an interested list. The other tools are the ones teams compare most often when they pick a MCP server for sales. Each one is described from its own website, pricing page and docs, checked on the dates below; OXYGEN's facts and prices come from the product and its live price list. Prices are the cheapest self-serve plan each vendor lists.
The products named here are trademarks of their owners and are not affiliated with OXYGEN. Something out of date? Tell us.