Karbon MCP Server runs on your own machine — the client starts it, so there is no endpoint to ping. 90 installs a week from npm. Last commit 16 Jul 2026.
Unofficial MCP server for Karbon practice management: contacts, work, time, invoices, payments.
What the code does
We read the source, 4 d ago · rules 995398eba69f
What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.
const result = spawnSync(command, ["--version"], {
Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.
This code can reach further than it looks
We found places where it runs commands, builds paths or queries from values it is given. None of that is a flaw by itself — it becomes one when the code changes, and code changes quietly between releases. We re-read it on every one.
Connect this server
This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.
claude mcp add karbon-mcp-server -e 'KARBON_BEARER_TOKEN=<KARBON_BEARER_TOKEN>' -e 'KARBON_ACCESS_KEY=<KARBON_ACCESS_KEY>' -- npx -y karbon-mcp-server{
"mcpServers": {
"karbon-mcp-server": {
"command": "npx",
"args": [
"-y",
"karbon-mcp-server"
],
"env": {
"KARBON_ACCESS_KEY": "<KARBON_ACCESS_KEY>",
"KARBON_BEARER_TOKEN": "<KARBON_BEARER_TOKEN>"
}
}
}
}[mcp_servers.karbon-mcp-server]
command = "npx"
args = ["-y", "karbon-mcp-server"]
env = { KARBON_BEARER_TOKEN = "<KARBON_BEARER_TOKEN>", KARBON_ACCESS_KEY = "<KARBON_ACCESS_KEY>" }{
"mcpServers": {
"karbon-mcp-server": {
"command": "npx",
"args": [
"-y",
"karbon-mcp-server"
],
"env": {
"KARBON_ACCESS_KEY": "<KARBON_ACCESS_KEY>",
"KARBON_BEARER_TOKEN": "<KARBON_BEARER_TOKEN>"
}
}
}
}{
"servers": {
"karbon-mcp-server": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"karbon-mcp-server"
],
"env": {
"KARBON_ACCESS_KEY": "<KARBON_ACCESS_KEY>",
"KARBON_BEARER_TOKEN": "<KARBON_BEARER_TOKEN>"
}
}
}
}Put your own values in place of
<KARBON_BEARER_TOKEN> (Bearer token (Application Authorization Token) from Karbon → Settings → Connected Apps → API Applications), <KARBON_ACCESS_KEY> (Access key (JWT starting with 'ey') from Karbon → Settings → Connected Apps → API Applications).
The author’s registry entry marks them as required.
Optional settings from the registry entry, left out of the block above:
KARBON_READ_ONLY (Set to 'true' to disable all create/update tools (they are not registered at all)), KARBON_ALLOW_PAYMENT_WRITES (Set to 'true' to enable the payment write tools (create/delete/reverse manual payments); off by default).
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Karbon MCP Server — questions
Answers built from our own checks of this server.