Reference
USMail.ai MCP
Quick answer
MCP is available now on the app. Agents use the human account (env login + short session token). Account + prepaid meter. A human still approves. Standalone API keys later.
Availability
Live means you can use it on the app after you register and fund. It does not mean an open server on the public internet. Planned means do not invent it yet.
| Capability | Now | Notes |
|---|---|---|
| Public docs (this site) | Yes | Indexable; accurate description |
| Human account + prepaid meter | Live | Required path for using the platform |
| MCP server for agents | Live | Production and lab. Same path as the portal |
| Standalone REST/API keys for AI | Planned | Not available yet — do not invent endpoints |
What this is
MCP is Model Context Protocol for this platform. An agent prepares print-to-mail jobs on the same production path as the portal. It is not a second product. It is not USPS.
The agent can upload documents and lists, set options, request proof, read status, and leave a draft. It stops there. You still open the app. English capabilities: Tools reference.
Mixed Name and Company lists are valid. After ingest, read the digested rows — not only the column map. Details: Tools reference.
Why a human still approves
Physical mail cannot be unsent once we produce it. Certified Mail is proof when you select it. The meter spends real postage. An agent can assemble a clean job and still be wrong about the recipient, the class, or the date.
You are the last check. Approve on the app is the spend. Until you confirm, the job is a draft. After you confirm, production starts. That gate is the product, not a temporary limit.
Agents prepare. They do not run card deposits. They do not approve production mail, including Certified. If you wait for the agent to press produce, the job stays a draft.
Same production path
One backend. Portal jobs and agent jobs share it. We print, insert, apply postage, and deliver the pieces to USPS. Cutoffs and tracing match the portal. How it works →
Certified Mail and Certificate of Mailing when you configure them on the job. Not for postcards. Never same-day. Flagged Certified addresses cannot still-mail. Certified →
CASS and NCOA run on the production path. Tracing on qualifying First-Class letters and postcards is not tracking and is not Certified proof. Address verification →
Documents and postcards. Statement or invoice jobs use uploaded files and lists. We do not generate bills inside a core or ERP. You still approve each job.
Not a public mail API
There is no open server for anonymous tool calls. There is no free public mailbox for agents. The agent uses the human account from environment variables. Credentials stay in env. Never in the prompt. Never in a public repo.
A session token is not a standalone API key. Standalone API keys are planned. They are not the path now. Do not invent endpoints. Do not invent hostnames or add commands. Do not paste an install string from a blog.
Auth and the meter: Auth & billing. Account practices: Security.
Flow
A human registers. A human funds the meter in the app. You put credentials in env. The agent logs in for a session token and calls tools. Then you approve on the app. Approve debits the meter and starts production. Then we produce and hand off to USPS.
Six steps, with failure notes: Getting started →
Not included
- Public free MCP mailing
- Unauthenticated public MCP
- Standalone API keys outside the meter (planned later)
- Live hostnames / install strings (issued with access)
- Agent card deposits
- Agent approve of production mail
Production mail is not free. Insufficient balance blocks production. There is no silent overdraft.
FAQ
What is the USMail.ai MCP?
A Model Context Protocol integration so AI agents can prepare print-to-mail jobs on the same production path as the portal. Account plus prepaid meter. Login returns a short session token. A human on the app approves.
Is it available now?
Yes. MCP is available now on the app. Account + prepaid meter required. Agent uses env login and a short session token. A human on the app approves. Not an unauthenticated public endpoint. Get started.
How does billing work for MCP?
Account + prepaid meter. A human funds the meter in the app. Approve on the app debits it. Agents do not run card deposits. Standalone API keys are planned later. Production mail is not free. Auth & billing →
Do agents use a different mail pipeline than humans?
No. One production path for portal and MCP. We print, insert, apply postage, and deliver the pieces to USPS. Certified options when selected. A human still approves.
Why does a human still approve?
Physical mail cannot be unsent once we produce it. The meter spends real postage. Certified Mail is proof when selected. An agent can assemble a clean job and still be wrong about the recipient, the class, or the date. Approve on the app is the last check and the spend.
Are mixed Name and Company lists valid?
Yes. Mixed files are valid. Some rows have a person and a company. Some have only a name (the name is the company). Empty company on those name-only rows is correct. After ingest, read the digested rows. Column maps alone are not proof the company values arrived. Tools reference →
Is this a public unauthenticated mail API?
No. MCP is not a public unauthenticated endpoint. The agent uses the human account from environment variables and a short session token. Do not invent hostnames or add commands.
Get MCP access
Account + meter required for MCP enablement.