The Prosaic MCP server

What is our MCP server and what can you do with it?

Prosaic's MCP server is how an AI assistant works directly in your books. It puts 64 tools in front of Claude, ChatGPT or any other assistant that speaks MCP, covering entities, bank transactions, reconciliation, journals, the ledger, the chart of accounts, fixed assets, GST returns, invoices, reports, rules, scheduled tasks and extensions.

If you just want to get connected, Connecting Prosaic to AI Assistants (MCP) walks through the setup for each platform. This article is the fuller picture: what an MCP server actually is, what sits behind Prosaic's, and what each group of tools lets you do.

In this article

• What an MCP server is
• The server address, and connecting
• What makes ours different
• What's in the toolkit
• The API underneath
• What it won't do

What an MCP server is

MCP stands for Model Context Protocol. It's the open standard AI assistants use to connect to other software, and an MCP server is one application's side of that connection.

The useful way to think about it: an MCP server is an interface into an application's API, written so an assistant can use it. Instead of you clicking through Prosaic, the assistant is handed a set of labelled tools, each one a specific job, such as "list bank transactions for this entity" or "create a journal". You describe what you want in ordinary language, the assistant works out which tools to call and in what order, and the server carries the work out against your Prosaic data.

Every tool goes through Prosaic's public API, the same one our own integrations use, so an assistant is subject to exactly the same validation as any other client. A journal still has to balance. A reconciliation still has to satisfy the rules the app applies.

The server address, and connecting

The Prosaic MCP server lives at:

https://mcp.prosaic.works/mcp

That address is the same for every assistant, so the only thing that changes between platforms is where you paste it. You authorise the connection by signing in to Prosaic, which means the assistant works inside your existing access, not alongside it. You can check the server is up at any time by visiting https://mcp.prosaic.works/health.

Setup takes a couple of minutes per platform. Connecting Prosaic to AI Assistants (MCP) has step-by-step instructions for Claude (desktop, web and Claude Code), ChatGPT and Perplexity, along with troubleshooting if a connection doesn't take.

What makes ours different

Plenty of accounting systems now offer an MCP server. A few things set Prosaic's apart.

One sign-in reaches the whole workspace

You authorise once, as yourself, and every client and entity your Prosaic role can see is available in the conversation. There's no connecting one organisation at a time and no reconnecting when you switch clients, which is what makes practice-wide questions possible: "which of my clients have a GST return due in the next fortnight", or "go through all my entities and flag any with more than 50 unreconciled transactions".

The whole API, not a highlights reel

The 64 tools cover essentially everything our public API does. It isn't a read-only summary layer bolted onto the side of the product: the tools are the API, so an assistant can reach the same functionality your own integration would.

It writes, not just reads

Reconciling, posting journals, creating invoices, editing the chart of accounts, creating and amending rules, all of it is available. Assistants ask you to confirm before anything that changes your data, so you stay the one approving the work, but the work itself genuinely happens rather than being drafted for you to re-enter.

Bank transactions and reconciliation are first-class

This is the daily work, so it gets proper treatment: list and filter transactions, reconcile one with full control over tax treatment and split lines, reconcile up to 500 at once in a single batch, and reverse a reconciliation that turned out wrong. Attachments come along too, so a receipt can be uploaded and coded in the same breath.

It reaches the automation layer

Most integrations stop at the ledger. Ours also exposes the three things that let work keep happening when you aren't watching: rules, which auto-suggest postings for matching transactions; scheduled tasks, which run an instruction unattended on a cadence and email you the result; and extensions, which an assistant can scaffold and validate for you if your practice builds its own integrations.

What's in the toolkit

The 64 tools group into eleven areas. You never call a tool by name, you just describe the job, but knowing what's there tells you what's worth asking for.

Entities and clients (5 tools)

List the entities and clients you have access to, create new ones, and generate a magic onboarding link so a client can connect their own bank feeds.

• "Create a new client for Sarah Thompson and send her an onboarding invite"
• "Show me every entity linked to the Morrison Group"

Bank transactions and reconciliation (5 tools)

List transactions for an entity with date filtering, reconcile one transaction across as many account lines as you need, bulk reconcile up to 500 at a time, reverse a reconciliation, and list your own connected bank feeds separately from your clients'.

• "Show me what's left to reconcile for Wellington Rentals and help me work through it"
• "Reconcile all the Spark and Contact Energy bills across my sole trader entities"
• "That Z Energy transaction was coded to the wrong entity, reverse it"

Journals, files and the ledger (7 tools)

Create manual journals with double-entry lines, post them or leave them as drafts, attach supporting files, and read the ledger three ways: a flat paginated list, grouped by account with balances, or as a full general ledger export. Files up to 20MB can be uploaded and attached, including PDFs, images, spreadsheets and Outlook messages.

• "Create the monthly rent accrual journal for 123 Queen St, and attach this statement"
• "Show me the general ledger for ABC Company for last quarter"
• "What's the balance on the motor vehicle account for Smith Family Trust?"

Chart of accounts and templates (15 tools)

The largest group, because conversions live here. Read and edit an entity's chart, browse the global account library, and build or amend the chart templates your entities are based on, right down to adding, renaming or removing a single template account without resending the whole list. Changes to a template propagate to every entity using it.

• "Add a subcode under Repairs and Maintenance for the Tauranga property"
• "Compare this Xero chart against our standard template and tell me what's missing"

Financial reports (5 tools)

Profit and loss, balance sheet, trial balance, current accounts and the depreciation schedule, each with period selection and comparison columns across prior years or months.

• "Run a profit and loss for Wellington Rentals for the last financial year with a prior year comparison"
• "Give me the trial balance for Smith Family Trust as at 31 March"

GST returns (3 tools, read-only)

Read a single return with its full IRD box breakdown (boxes 5 to 15), list returns for one entity, or list them across the entire workspace. Each row carries the status, period, filing due date, whether it's overdue, the net GST position and how many transactions in the period are still unreconciled.

• "Which of my clients have a GST return due in the next two weeks?"
• "List any GST returns that are overdue, and how many transactions are still unreconciled on each"

Fixed assets (5 tools)

List and create assets, read one with its depreciation detail, and manage the asset type categories that carry the depreciation settings and account mappings.

• "List all active fixed assets for Jones Partnership"
• "Add the new work ute as a motor vehicle asset, purchased 12 March for $38,000"

Invoices (3 tools)

List invoices across the workspace or narrow by entity, client or status, read one with its line items, and create a finalised invoice. Creating an invoice doesn't send it to the recipient, so you can review it in Prosaic first.

• "Show me every unpaid invoice across the workspace, oldest first"

Rules (5 tools)

Create, read, amend and delete the rules that auto-suggest journal postings for matching bank transactions, either workspace-wide or scoped to particular entities.

• "Create a rule that codes anything from Z Energy to motor vehicle expenses"
• "What rules apply to Bright Property Ltd, and is anything duplicated?"

Scheduled tasks (6 tools)

Set up an instruction that runs unattended on a cadence in New Zealand time and emails the result, then edit it, pause it, delete it, or trigger a one-off run to see what it does before you trust it. A workspace can hold up to 25.

• "Set up a daily task at 10am to reconcile any sole trader clients, then email me a summary"
• "What scheduled tasks are running in this workspace, and when did each last run?"

Extensions (5 tools)

For practices building their own integrations: scaffold a complete extension project, list the permission scopes and event triggers available, validate a manifest before you deploy, and pull the full extensions reference in one go.

• "Scaffold an extension that posts to our Slack whenever a GST return is finalised"

The API underneath

Every MCP tool is a thin wrapper over Prosaic's public API, so if you want to know precisely what a tool can accept or return, the API reference is the definitive answer. It's published at app.prosaic.works/api/reference, with every endpoint, its parameters, and a live client you can try requests from.

The same API is available to you directly, which matters if you're building something the MCP server doesn't cover, or want a scheduled job running on your own infrastructure. It authenticates either with an API key (quickest, generated in Prosaic under Settings → Users) or with OAuth 2.1 for applications acting on behalf of other Prosaic users. The public API is in open beta, and the team is at developer@prosaic.works if you're starting a build.

What it won't do

• Filing GST returns stays in Prosaic. An assistant can read a return and every IRD box on it, but finalising and filing with IRD happen in the app, where you can see exactly what you're approving.
• It has no more access than you do. The connection runs on your own sign-in, so an assistant can only reach the workspaces and entities you can reach yourself.
• It isn't a substitute for reviewing the work. Check what comes back the way you'd check a colleague's, particularly on anything posted in bulk.

A note on bulk reconciliation: a successful response means the batch was accepted, not that every transaction is done. Individual journals can still be rejected afterwards, most often for a missing dimension, so ask the assistant to re-read the transactions and confirm rather than treating the first answer as final.

Need help?

If you build something useful on top of the MCP server, or hit a job it can't quite do yet, we'd like to hear about it. Use the 💬 button in the app or email help@prosaic.works.