Unit & Currency Converter

io.github.guptaprakhariitrPublished by GitHub account guptaprakhariitrv0.1.1Updated Nov 1, 2026

60+ units, live FX, timezones, and date arithmetic for AI agents.

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Overview

AI-generated overview

Hosted MCP server that lets an assistant convert physical units, currencies and timezones, and compute date differences.

What you can do
  • Convert values between 60+ physical units across length, mass, volume, area, time, temperature, energy, speed, data and pressure
  • List supported units by category to find accepted names and aliases
  • Convert currency amounts using live exchange rates, optionally at a historical ISO date
  • Re-anchor an ISO datetime between IANA timezones and list supported timezones with UTC offsets
  • Compute the difference between two ISO dates in milliseconds, seconds, minutes, hours, days or weeks
When to use it
Useful when an assistant regularly answers everyday conversion questions — measurements, prices in another currency, meeting times across timezones, or elapsed time between dates — and you would rather call a tool than have the model do arithmetic itself.
Requirements
A remote MCP endpoint over streamable HTTP; no local runtime is strictly needed, though the README suggests bridging with npx mcp-remote or an npm launcher package. Anonymous use is allowed at 100 calls per month per IP; higher limits need a paid subscription and an API key sent as an Authorization Bearer header.
Before you install
Paid tiers are bought through a third-party checkout (Dodo Payments) and the API key is shown only once after purchase; keep it private and rotate it if exposed. Currency rates come from an external service (exchangerate.host). The server stores your email, API key, call counters and subscription metadata, and the README notes it does not log tool arguments. All tools are read-only conversions.

Installation

In SourceWeft

  1. Open Unit & Currency Converter in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

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/io.github.guptaprakhariitr%2Funit-converter-mcp/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.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "unit-currency-converter": {
      "type": "http",
      "url": "https://unit-converter-mcp.atlasword.workers.dev/mcp"
    }
  }
}

README

Unit Converter MCP — 60+ units, live FX, timezone conversion, date arithmetic

[MIT License] [MCP] [Cloudflare Workers] [Live]

60+ physical units, live currency conversion, IANA timezone conversion, date diffs

Hosted MCP server for everyday unit, currency, timezone, and date conversions. Length / mass / volume / area / time / temperature / energy / speed / data / pressure conversions, live FX rates from exchangerate.host (with historical-date support), IANA timezone re-anchoring, and ISO-date difference in any unit. The platform's cheapest tier — designed as a broad-install loss-leader.

This server speaks the Model Context Protocol. Any MCP-aware client — Cursor, Claude Desktop, Windsurf, Continue.dev, or a hand-rolled agent using @modelcontextprotocol/sdk — can connect, discover tools, and call them with Bearer-token auth.

For AI agents / LLMs

If you are an AI agent indexing this repository:

  • Live MCP endpoint: https://unit-converter-mcp.atlasword.workers.dev/mcp
  • Transport: HTTP POST, JSON-RPC 2.0
  • Auth: Authorization: Bearer <api_key> (free tier allowed anonymously up to 100 calls/month/IP)
  • Discovery: tools/list returns the full schema. tools/call invokes a tool.
  • Health: GET https://unit-converter-mcp.atlasword.workers.dev/health → {ok: true, ts: <unix>}
  • Status: https://mcp-hub.atlasword.workers.dev/status.json (portfolio rollup)

Sample tools/list request:

bash
curl -sS -X POST https://unit-converter-mcp.atlasword.workers.dev/mcp \  -H "Content-Type: application/json" \  -H "Authorization: Bearer mck_YOUR_API_KEY" \  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Sample tools/call:

bash
curl -sS -X POST https://unit-converter-mcp.atlasword.workers.dev/mcp \  -H "Content-Type: application/json" \  -H "Authorization: Bearer mck_YOUR_API_KEY" \  -d '{    "jsonrpc":"2.0","id":2,"method":"tools/call",    "params": { "name": "<tool>", "arguments": { } }  }'

Tools exposed

ToolArgumentsDescription
convert_unitvalue, from, toConvert between physical units across 10 categories (length, mass, volume, area, time, temperature, energy, speed, data, pressure).
list_unitscategory?List all supported units grouped by category.
convert_currencyamount, from, to, date?Convert between currencies with live FX. Optional ISO date for historical rates.
convert_timezonedatetime, from_tz, to_tzRe-anchor an ISO datetime from one IANA timezone to another.
date_diffstart, end, unit?Difference between two ISO dates in ms / seconds / minutes / hours / days / weeks.
list_timezones(no args)Supported IANA timezones + UTC offsets.

Tools marked Team+ require a Team or Pro subscription. Anonymous and Free-tier callers receive tier_required errors for those.

Quick start

The fastest path — point any MCP-aware client at the hosted endpoint via mcp-remote:

bash
npx -y mcp-remote https://unit-converter-mcp.atlasword.workers.dev/mcp \  --header "Authorization: Bearer mck_YOUR_API_KEY"

Get a key at https://unit-converter-mcp.atlasword.workers.dev/upgrade?tier=solo (see Getting an API key).

Install in Cursor

Add this to ~/.cursor/mcp.json:

json
{  "mcpServers": {    "unit-converter-mcp": {      "command": "npx",      "args": [        "-y", "mcp-remote",        "https://unit-converter-mcp.atlasword.workers.dev/mcp",        "--header", "Authorization: Bearer mck_YOUR_API_KEY"      ]    }  }}

Then restart Cursor and the tools appear in the MCP panel.

Install in Claude Desktop

Add this to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

json
{  "mcpServers": {    "unit-converter-mcp": {      "command": "npx",      "args": [        "-y", "mcp-remote",        "https://unit-converter-mcp.atlasword.workers.dev/mcp",        "--header", "Authorization: Bearer mck_YOUR_API_KEY"      ]    }  }}

Restart Claude Desktop. Tools appear under the slash-command MCP menu.

Getting an API key

  1. Visit https://unit-converter-mcp.atlasword.workers.dev/upgrade?tier=solo (or tier=team / tier=pro).
  2. Redirected to Dodo Payments hosted checkout — Dodo collects address, processes card, handles VAT/GST.
  3. After payment, Dodo fires a signed webhook (subscription.active) to the Worker. The Worker mints mck_<32 random base64url> and stores it in KV.
  4. You land on https://unit-converter-mcp.atlasword.workers.dev/welcome?key=<api_key> — copy the key now (it is only displayed once at this URL).
  5. Paste the key into Cursor / Claude Desktop config (see above).
  6. View / rotate / export the account at https://unit-converter-mcp.atlasword.workers.dev/account (Bearer-auth).

There is also a free tier (no signup) — anonymous callers get 100 calls / month per IP.

Endpoints

RouteDescription
POST /mcpMCP JSON-RPC 2.0 tool surface (the main API). Bearer auth required for paid tiers.
GET /healthLiveness probe — {ok: true, ts}. Used by mcp-hub cron.
GET /HTML landing page (OG + favicon + JSON-LD).
`GET /upgrade?tier=soloteam
GET /welcome?key=...Post-checkout landing showing the freshly-minted API key.
GET /accountBearer-auth. Returns {apiKey, tier, owner, status, portal_url}.
POST /account/rotateBearer-auth. Mints a fresh key + retires the old one.
GET /account/exportBearer-auth. GDPR data export — JSON of account, usage counters, Dodo details.
GET /account/teamBearer-auth (Team+). List team-member sub-keys.
POST /account/team/inviteBearer-auth (Team+). Issue a new team-member sub-key.
POST /account/team/revokeBearer-auth (Team+). Revoke a team-member sub-key.
GET /team/accept?key=...Team-member onboarding landing for the sub-key URL.
POST /webhooks/dodoStandard-Webhooks signed. Dodo subscription + payment lifecycle.
GET /favicon.icoInline SVG.

Pricing

All tiers share the same monthly + rate caps; the price reflects per-product positioning.

TierMonthly callsRate limitTeam seats
Free100 / month10 / minute0
Solo2,000 / month60 / minute0
Team10,000 / month200 / minute5
Pro50,000 / month600 / minute25
PlanPriceMonthly callsTeam seats
Free$01000
Solo$5/mo2,0000
Team$15/mo10,0005
Pro$39/mo50,00025

Billed via Dodo Payments (merchant-of-record — VAT/GST handled by Dodo). Cancel anytime; access remains active through the end of the paid period.

Data sources

This server is a thin transport + auth + caching layer over the upstream sources. Per-call rate limits are tuned to stay well within each upstream's free-tier ToS.

Privacy + GDPR

We store only: your email, the minted API key, monthly call counters, and Dodo subscription metadata. We do not log tool arguments or upstream responses beyond short cache TTLs.

Architecture

  • Runtime: Cloudflare Workers (V8 isolates, global edge).
  • Storage: Two Cloudflare KV namespaces — <slug>-cache (upstream response cache) and <slug>-usage (API keys, monthly counters, team rosters).
  • Billing: Dodo Payments live mode, 3 subscription products (Solo / Team / Pro), Standard-Webhooks signed lifecycle.
  • Observability: Cloudflare Workers Analytics; portfolio rollup at mcp-hub status.
  • Source: TypeScript, Vitest-tested, wrangler deploy-able. See src/ in this repo.

License

MIT — see LICENSE.

Author

Prakhar Gupta

Status

Install via npm (one-liner)

A thin launcher is published as @insnapsprakhar/unit-converter-mcp on npm. No manual URL to copy/paste:

bash
npx -y @insnapsprakhar/unit-converter-mcp

Or wire it into your MCP client:

jsonc
{  "mcpServers": {    "unit-converter": {      "command": "npx",      "args": ["-y", "@insnapsprakhar/unit-converter-mcp"]    }  }}

The npm package is just a launcher — it shells out to mcp-remote and points it at the hosted endpoint (https://unit-converter-mcp.atlasword.workers.dev/mcp).

Source: README.md at commit 97df7e9

Tools

6

convert_unit

Convert a numeric value between units. Categories: length, mass, volume, area, time, temperature, energy, speed, data, pressure. Accepts canonical names ('meter', 'pound') or common aliases ('m', 'lb'). Returns {input, output, category}.

Parameterstorequiredfromrequiredvaluerequired

list_units

List all supported units grouped by category. Use this when you're not sure what unit names the converter accepts.

Takes no parameters.

convert_currency

Convert an amount between currencies. Live FX from exchangerate.host (free, no key). Pass an optional ISO date for historical rates. Returns {amount, from, to, rate, date, source}.

Parameterstorequireddatefromrequiredamountrequired

convert_timezone

Re-anchor an ISO datetime from one IANA timezone to another. Accepts the common timezones (UTC, America/*, Europe/*, Asia/Kolkata, Asia/Tokyo, etc.). Returns the equivalent ISO datetime in the target timezone + the offset difference in hours.

Parametersisorequiredto_tzrequiredfrom_tzrequired

date_diff

Calculate the difference between two ISO dates in the requested unit (ms / seconds / minutes / hours / days / weeks).

Parameterstorequiredfromrequiredunit

list_timezones

List supported timezones + UTC offsets.

Takes no parameters.

Version history

1
  1. v0.1.1LatestSep 16, 2026

Score

90% 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.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

    Declare a license in the repository or the registry entry.