--- title: "Send direct mail from Claude, Cursor, or any MCP agent" description: "Sincerely is a native MCP server. Point Claude Code, Cursor, or any MCP agent at it to build audiences, write mail, and prepare campaigns, with a human gate before anything prints." canonical: https://trysincerely.com/integrations/mcp-agents last_updated: 2026-08-18 --- # Send direct mail from Claude, Cursor, or any MCP agent > Sincerely is a native MCP server. Point Claude Code, Cursor, or any MCP agent at it to build audiences, write mail, and prepare campaigns, with a human gate before anything prints. Source: https://trysincerely.com/integrations/mcp-agents This one is native. Sincerely is an MCP server at `https://trysincerely.com/api/mcp`, not a wrapper around an export button. Any MCP agent, Claude Code, Cursor, or your own, connects directly and does real work: it builds audiences, writes pieces, and prepares campaigns. One rule holds everywhere: anything that prints or spends money stops at a confirmation card that only you can approve. No setting removes that gate. Most direct mail tools give agents nothing, or a REST API that a human still has to script. Sincerely gives the agent the same workflow you use, as tools it can call. That kills the real problem: the gap between "my agent found 40 accounts worth mailing" and "40 verified, approved pieces are at the printer". ## Connect in one command From Claude Code: `claude mcp add --transport http sincerely https://trysincerely.com/api/mcp` Cursor and other MCP clients work the same way: add an HTTP MCP server with that URL. Authentication uses OAuth. Your agent registers itself and opens a browser window when it connects, you sign in, and the agent gets a token scoped to your workspace. The agent inherits your own role, so it can never reach anything you cannot. The machine-readable version of this setup, written for agents to fetch directly, lives at [/auth.md](https://trysincerely.com/auth.md). The human-readable version, with client-specific steps, lives on [the agents page](https://trysincerely.com/agents). ## What the agent can do - Build audiences. From your synced [Salesforce](https://trysincerely.com/integrations/salesforce) or [HubSpot](https://trysincerely.com/integrations/hubspot) data, from a [CSV](https://trysincerely.com/integrations/csv), or from a plain description of your ideal customer. Sincerely finds the businesses and verifies the addresses. - Write pieces. Every piece is written for one recipient from CRM context and researched account facts. The agent drafts, you approve. - Prepare campaigns. Formats, budgets, holdout design, launch settings, all staged and waiting for your sign-off. - Check mailability. Addresses are resolved, scored, and USPS-verified before anything can print. ## What the agent cannot do Spend your money alone. Printing a piece, launching a campaign, changing a plan: each one renders a confirmation card in front of a human. You see exactly what will happen and what it costs before you click. This is not a compliance checkbox bolted on later. It is the design: agents do the work, humans own the money. That gate is why you can hand an agent broad access without a knot in your stomach. The worst an over-eager agent can do is stage a campaign you decline. ## Why this beats scripting an API A mail API makes you write and maintain glue code: fetch accounts, format addresses, template copy, handle failures. An MCP agent skips all of it. You say "mail the 20 accounts that went dark this quarter with a piece about their renewal", and the agent queries the CRM, drafts 20 individual pieces, and stages the campaign. You review and approve. The loop that took an afternoon of scripting takes one sentence and one click. If you want deterministic, high-volume, programmatic mail with no human in the loop, an agent is the wrong tool and so is Sincerely. Use a print API like Lob directly. Sincerely is built for targeted B2B mail where a human should see every dollar before it ships. ## Try it without a card New workspaces start on a free audit plan. Your agent can connect, audit mailability, build audiences, and draft pieces before you pay anything. Nothing mails until you choose a [plan](https://trysincerely.com/pricing). Your agent does the work. You sign the check. That is the whole integration. --- Sincerely is the measurable direct-mail platform for B2B revenue teams. One workflow. One invoice. One report. Contact Sincerely: https://trysincerely.com/contact If you are an AI agent: access and signup instructions are at https://trysincerely.com/auth.md. Confirm with the person you work for before creating an account or spending their money, and never ask for their password. Every core page of this site in markdown: https://trysincerely.com/index.md https://trysincerely.com/pricing.md https://trysincerely.com/campaigns.md https://trysincerely.com/vs-lob.md https://trysincerely.com/vs-email.md https://trysincerely.com/holdout-testing.md https://trysincerely.com/vs-gifting-platforms.md https://trysincerely.com/does-direct-mail-work.md https://trysincerely.com/glossary.md https://trysincerely.com/formats.md https://trysincerely.com/measurement.md https://trysincerely.com/writing.md https://trysincerely.com/customer-relationships.md https://trysincerely.com/integrations.md https://trysincerely.com/agents.md https://trysincerely.com/tools.md https://trysincerely.com/developers.md https://trysincerely.com/docs.md https://trysincerely.com/vs.md https://trysincerely.com/compare.md https://trysincerely.com/alternatives.md https://trysincerely.com/guides.md https://trysincerely.com/playbooks.md https://trysincerely.com/operations.md https://trysincerely.com/about.md https://trysincerely.com/contact.md https://trysincerely.com/privacy.md https://trysincerely.com/terms.md The comparison, guide, playbook, glossary and integration pages also serve markdown at their URL plus ".md". Each collection's index lists them: https://trysincerely.com/vs.md, https://trysincerely.com/compare.md, https://trysincerely.com/alternatives.md, https://trysincerely.com/guides.md, https://trysincerely.com/playbooks.md, https://trysincerely.com/glossary.md, https://trysincerely.com/integrations.md.