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MCP Per Diem in Claude Code

Statutory travel allowances on the rate tables the tax authorities publish, and the trips you priced with them. It prices one business trip against a bundled rate table and shows the arithmetic that produced the number: the allowance per day, the partial-day fraction the scheme's own ladder gave, every deduction for a meal somebody else paid for, and the total in the scheme's own currency. Three schemes ship with it, the Polish delegation regulation at home and per country, the HMRC benchmark scale rates for travel inside the UK, and the US GSA CONUS standard M&IE with the lodging cap. Start and end are instants rather than wall clocks, so a trip across a clock change is 23 or 25 hours, and the Polish 24-hour period and the US calendar day give different and equally correct answers to the same trip. Trips can be saved under a name with a TRIP-YYYY-NNNN id, listed with a total per currency, reported per scheme and per month, and handed to the expense tracker as ready-made expense_add arguments. The tables are files inside the package rather than a feed, so the same trip priced twice gives the same answer, and every rate carries its authority, instrument, source URL and effective date.

`claude mcp add per-diem` at user scope is the right level: rate tables and saved trips are per person, not per repository, and the five free trips a month are counted once for the machine rather than once per project. Nothing here touches the network, so it works the same on a plane as at a desk.

What you get in Claude Code

You sayTool
What is the per diem for 58 hours in Krakow, leaving Tuesday at 8am, with breakfast provided on the first day and two hotel nights?perdiem_calc
Price the same trip under the HMRC benchmark rates instead.perdiem_calc
Save that as the Krakow audit trip and show me what I have claimed this quarter.trip_record

A destination that is not in the bundled table is refused by name rather than priced at a neighbour's rate. Measured through a real client on 2026-09-05: asked for a Polish per diem for Oman, the model called perdiem_calc, got back the server's own refusal (Poland domestic plus 34 countries abroad are bundled, so a missing country means not verified here rather than no rate exists), called perdiem_rates to check the coverage for itself, and then said plainly that it would not guess a number. An earlier build of this server answered that same trip with Romania's EUR 42.00 diet, because "romania".includes("oman") is true; the fallback is a prefix match now. In the same session a 58-hour Krakow trip came back at PLN 258.75, PLN 123.75 of diets plus PLN 135.00 of lodging ryczalt, with the arguments assembled from the prose unprompted.

Install it in Claude Code

The file is .mcp.json, and the key inside it is mcpServers.

ScopePath
local (default)~/.claude.json, this project only
project.mcp.json at the repository root
user~/.claude.json, every project
claude mcp add per-diem -- npx -y @theluckystrike/mcp-per-diem
claude mcp list    # health-check it before the first prompt

# or --scope project, committed to .mcp.json for the team

No restart. The entry is picked up in the next session, and `/mcp` reconnects one on demand.

The npm publish of @theluckystrike/mcp-per-diem is pending; until then use the .mcpb bundle or a clone and build from the latest release.

No install: the hosted endpoint

There is no hosted endpoint for this one yet. MCP Per Diem runs locally over stdio with the config above, which is also the only form in which it reads and writes files on your own disk. Three of the servers in this collection are served at https://mcp.zovo.one/mcp/<name> over MCP streamable HTTP: time-tracker, price-tracker and invoice.

Claude Code notes worth knowing first

The `--` is load-bearing: it separates Claude Code's own options, such as --transport, --env and --scope, from the command that runs the server. And the default scope is local, private to you and to the directory you ran it in, so adding it in the wrong folder leaves the tools absent with no error at all.

Free: Rate lookups and calculations are unlimited on every tier, on all three schemes: the tables are public regulation, and metering the reading of a regulation would be charging for the tax authority's work rather than for this server's. 5 trips saved a calendar month, counted by start date, and unlimited trip lists. Pro is $19 once, verified offline.

Questions

Which scope should I use for MCP Per Diem?

Local, the default, writes ~/.claude.json and is private to you and that directory. --scope project writes .mcp.json at the repository root, shared through version control. --scope user loads it everywhere.

Why did my first prompt ignore the server?

Measured, not documented: of three fresh projects, one first prompt made zero tool calls although initialize answered in 1.05 seconds. Run claude mcp list once first: it prints Connected, and the next run used the tool.

Can I use MCP Per Diem without installing anything?

Not yet. MCP Per Diem runs locally over stdio, which is also how it reads and writes files on your disk. The hosted endpoints at https://mcp.zovo.one/mcp currently cover time-tracker, price-tracker and invoice.

Related

MCP Per Diem in detail · The same server in Claude Desktop and Cursor · Every server in Claude Code · Guides · Claude Code docs · Buy Pro