Karbon announced a public MCP server on June 3, 2026, alongside Kai, its AI coworker. As of October 2026 an endpoint exists but is undocumented: Karbon's developer site lists an MCP server at mcp.karbonhq.com in its machine-readable index, with no tool list, no authentication notes, no release note and no announcement, and Kai remains in early access. What Karbon does have, and has had for years, is a well-documented REST API, which is why it is already the easiest Canadian practice management platform to put an agent in front of.
Status, verified October 2026
The announcement is in Karbon's June 3, 2026 press release and on Karbon's own site, which describe a public MCP server that connects Karbon to external AI tools over an open standard. Since then the only official trace is one line in the developer site's llms.txt, which lists an MCP server at mcp.karbonhq.com under its key links; the developer portal itself, the API release notes through September 23, 2026 and the product release notes through October 6, 2026 do not mention it, and the Kai feature page still shows early access. Third-party write-ups describe connecting Claude to that endpoint with a Karbon sign-in; Karbon has not published what it can do. There is no Karbon connector in Claude's directory and no ChatGPT plugin.
The API is documented at developers.karbonhq.com. It is a REST API authenticated with a bearer token plus a per-firm AccessKey header rather than OAuth, and it covers contacts, organizations, work items, notes, timelines, and client requests. A community-built karbon-mcp-server wraps parts of that API; it is unofficial and unsupported by Karbon. Zapier's MCP catalogue includes Karbon with contact actions only.
Status verified October 2026. We re-check this page quarterly; this one moves to shipped when Karbon documents the endpoint.
What an agent can do with Karbon today
Quite a lot, through the API. An agent can find a client's contact and work item, read the notes and timeline on a tax job, post a note, move a work item through its workflow statuses, and create client requests, which are the tracked to-do items the client sees in the Karbon for Clients portal. That last one is the piece that matters for intake: a missing-document follow-up becomes a specific request assigned to the client, with Karbon's own reminders behind it, instead of an email a preparer has to remember to send.
We built and published exactly this. Karbon T1 intake with an AI agent walks through an agent that watches for documents arriving on a Karbon work item, records the figures in the tax file, and turns each gap into a Karbon client request. When Karbon's MCP server ships, the API calls in that build become MCP tool calls; the workflow does not change.
Where Armada T1 fits
Armada T1 is the system of record for Canadian T1 intake, with its own MCP server. Karbon holds the client relationship and the work item; Armada T1 holds the tax file. An agent connected to both reads each document as it arrives, records slip and receipt data as validated section records with the source stored alongside, identifies the questions and documents still open, and routes each one as a task to the preparer or, through a Karbon client request, to the client. Armada T1 does not calculate or EFILE returns; the completed file is handed off to the CRA-certified tax software your firm already runs.
How to check for changes
Watch the API release notes, the developer portal and the Kai page. When Karbon documents the endpoint, the things to look for are whether it covers client requests and work item statuses or only contacts, and whether it is priced with Kai or included with the API. For the rest of the Canadian stack, see MCP servers for Canadian tax and accounting software.
This page describes third-party products as documented by their vendors in October 2026 and is not affiliated with or endorsed by Karbon. Karbon, Kai and Karbon for Clients are trademarks of Karbon, Inc. Claude is a trademark of Anthropic, PBC. Product availability changes; verify with the vendor before relying on it.
