Connect Claude or ChatGPT to fynxIQ and ask where each client stands: returns filed, what blocked a month, notices and due dates, and what it never sees.
- Turn on two-factor sign-in in fynxIQ, under Settings, Security. A connection is refused without it.
- In Claude, add a custom connector with the address https://fynxiq.com/api/mcp. In ChatGPT, add a custom MCP server with the same address and choose OAuth.
- The assistant opens fynxIQ’s own page. Sign in, pick the firm, tick what the assistant may do beyond reading, and press Allow.
- Ask it something: which clients have not filed their GSTR-1 for September, or what falls due this week.
In the app, on every plan, the free one included: Board, calendar and upload links, for CA firms.
What an assistant can read, and what it can do
fynxIQ speaks the Model Context Protocol, the open standard Claude, ChatGPT and other assistants use to reach other software. Once connected, the assistant can call seven tools that read what fynxIQ already keeps, and up to three that act, each only if you ticked it.
It reads with your login’s eyes. A firm’s owner and managers see every client; a staff member sees the clients assigned to them, exactly as on the firm board. A seller sees its own GST profiles.
- list_clients: every client you can see, with its GSTIN, frequency and scheme, and where its GSTR-1 and GSTR-3B stand for a month: filed with the ARN and day, ready, nil, blocked by how many checks, or nothing yet.
- period_blockers: for one client and month, how many checks blocked it and how many warned, and when it was last prepared or checked and by whom.
- filed_return_differences: how the GSTR-1 as filed differed from the one fynxIQ built, table by table, in rupees, where the filed return was compared.
- suspense_count: how many bank entries wait in Suspense for each client.
- open_notices: GST notices still to be answered, with the form, the kind and the reply date.
- due_dates: every return one client owes in the next one to twelve months, with extensions, and which are filed or overdue.
- settlement_warnings: what fynxIQ found in a month of a client’s marketplace settlements.
- If ticked: mark_period_filed records a GSTR-1 or GSTR-3B as filed with the ARN you give it; create_upload_link makes a link a client opens to send a month; send_reminder sends the due-date email for a client now.
What never leaves fynxIQ
The files a return is built from never reach fynxIQ’s server: they are read in your browser. So an assistant cannot see a sales report, a GSTR-2B, a bank statement or any line from one, because fynxIQ does not have them to give. It gets summaries: standings, counts, ARNs and dates, differences by table, findings by title.
It is also never given a supplier’s email or phone, a bank entry’s narration, or a notice’s reference, notes or reply, even though fynxIQ keeps some of those for you.
Which checks blocked a month is worked out on the prepare screen, in the browser, and only the count reaches the server. Asked what blocked September, the assistant says how many checks did and when, and points you to the prepare screen for each one; it does not guess. For a month a client sent through an upload link, the assistant is told which kinds of check it raised, by fynxIQ’s own name for each, never the words the client’s browser sent with them.
fynxIQ never files a return, through an assistant or otherwise. Marking a period filed records what you filed on the GST portal yourself, with the portal’s ARN, the same mark as on the board.
Connecting Claude
In Claude, open the settings where connectors live (Customize, then Connectors), add a custom connector, name it fynxIQ and give the address https://fynxiq.com/api/mcp. Claude finds fynxIQ’s sign-in page on its own; there is no key to copy.
A fynxIQ page opens. It names the assistant asking, the site your browser will be sent back to, and the firm the connection will act in, with a choice if you belong to more than one. Reading is always part of it. Each action is a tick of its own, on when Claude asked for it; take off any you do not want. Press Allow and you are back in Claude.
Claude reaches fynxIQ from its own servers, not from your computer, which is why the address has to be fynxIQ’s public one.
Connecting ChatGPT
In ChatGPT, open Settings and the section for apps (newer accounts call them plugins), add a custom MCP server with the address https://fynxiq.com/api/mcp, and choose OAuth as the way it signs in. The same fynxIQ page opens; answer it the same way.
ChatGPT, like Claude, asks for reading only unless you tick more, and offers only the tools your ticks allow, so it never suggests an action you did not give it.
What it will refuse, and why
Every call passes the same checks as fynxIQ’s portal access: two-factor sign-in must still be on, connectors must not be paused, the connection must be under 120 calls an hour (1,200 for the whole firm), and the client must be one of the connected firm’s that you are allowed to see. The first three come before any client is looked up, so a call refused for one of them says nothing about your clients. A refused call is answered in plain words, and is a line in the firm’s activity log.
A client you are not allowed to see gets the same answer as a client the firm does not have, so a connection never reveals the firm’s other clients to a staff member.
An action you did not tick is refused with the name of the tick that was left off. To add one, remove the connector in the assistant and connect it again.
Ending a connection
Settings has a section called Connected assistants: each connection with the assistant’s name, what it may do, when it was connected and when it was last used and for what. Revoke ends it at once; its next call is refused. A firm’s owner sees every connection in the firm and can revoke any of them.
Changing your fynxIQ password ends every connection you made, as it signs out every browser. Leaving a firm, or being removed from it, ends your connections there. Each connection made or ended, and each change made through one, is in the firm’s activity log with the assistant’s name.
In the app, on every plan, the free one included: Board, calendar and upload links, for CA firms.
Which file to download, and from where: the list for each marketplace and the GST portal.
By Raunak Pathak, founder of fynxIQ, who files GST returns on it. Last updated 6 October 2026. This is general information about how GST returns work, not advice about your particular return.