com.postalrefPublished by postalref.comOfficial publisherv0.2.0Updated Nov 2, 2026
USPS package barcodes, service type codes and mailing terms, each cited to its USPS source.
Answers USPS mailing questions — package barcodes, service type codes, terms and PostalPro documents — each cited to its USPS source passage.
Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.
Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.
Read https://sourceweft.com/mcp/com.postalref%2Fpostalref/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.Add this to your client's mcpServers config.
{
"mcpServers": {
"postalref": {
"type": "http",
"url": "https://postalref.com/mcp"
}
}
}Decode a barcode
Read a package barcode or tracking number (IMpb): its layout, each field's digits and meaning, whether the check digit holds, and the service type code's row in the USPS list, each with the passage that says so.
barcoderequiredLook up a code
Look up a USPS code: its row as USPS prints it in the newest edition that lists it, the codes its cells name, the editions that list it and its history, each row with its passage id. A code is found without the marks USPS prints around it and in a row USPS prints for several codes: 750 finds *750, 858 finds 858 and the dropped 858**, and 13 finds PTR's row 01 / 13. Two digits are also tried as three: 55 finds PTR's 55, then STC's 055.
coderequiredtableCompare two editions
What changed in a code table or document between two editions: each code added, removed or changed and each changed section, rated editorial, additive or breaking, with who rated it.
tocodefromlimitsubjectrequiredseveritySearch codes and terms
Search the codes, terms, banner texts, specs and documents postalref models, by one index: names and codes whose key is the query's first, then those that start with it, then those with words that start with its words, then codes whose row has its words. A term hit carries its kind (mail-class, extra-service, service, program, system, file, identifier, document, facility, container, role or term) and its tier (core, or reference: only in Publication 32, the glossary of July 2013, with that date). A query of 20 or more digits comes back as one to decode.
limitqueryrequiredDefine a USPS term
What USPS means by a name or abbreviation: each registry entry it names, in the order search ranks them, with its kind and tier, the USPS words that define it and the page they're on, its other names, postalref's own explanation where it has one, and postalref's page about it.
namerequiredlimitRead a USPS document
Read a revision of a modeled USPS document page by page, as extracted, to quote it: a quote cites the revision's sha256, the PDF page and the words exactly.
findpagepagesdocumentrequiredrevisionSearch PostalPro documents
Search every document on PostalPro by title and file name, with its page and newest file. postalref models a few of them; those carry a slug for read_source.
limitqueryrequiredtopic72% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
Publish an icon in the registry entry.
Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.
A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.