Mercoa MCP server

Query and manage Mercoa AP/AR bill-pay: entities, invoices, transactions and payment methods. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.

Connect MercoaFree 50 tool calls / monthPro $9/mo · $90/yr · pricing21 tools

What can I ask?

Turn on the Mercoa connector, then ask in plain words. The AI picks the tools.

Which bills are waiting for approval this week?
Show me all invoices from vendor Acme Ltd this quarter.
What were our total invoice amounts by status this month?
Add a comment on invoice INV-2041 saying it was checked against the PO.

What you can do with Mercoa in Claude and ChatGPT

For finance teams that pay vendor bills and send invoices through Mercoa.

Find bills that wait for approval

The AI searches invoices by status, entity, date and approver and opens each one. You get the bills that need an approver, with amount and vendor.

See the history of an invoice

The AI reads the audit log of an invoice: status changes, approvals and payments, so you can tell who did what and when.

Total invoice amounts per entity and currency

The AI reads invoice totals and counts for an entity's payables or receivables, grouped by currency, for AP and AR overviews and aging.

Check payment transactions for an invoice or entity

The AI searches payment transactions by entity, invoice, status, type and date and opens one to read it.

Find or add a vendor or customer

The AI searches entities by name, email or foreign id. If none exists, it creates a new entity with its role flags and a business or individual profile.

Changes data

Create a bill, update it or add a comment

The AI creates an invoice as a draft or submitted bill, moves its status forward, changes amounts, dates or payment methods, or adds a comment to its log.

Changes data

How do I connect Mercoa?

Before you connect

The login page asks for your Mercoa API key.

Find it in your Mercoa dashboard under API keys. Your key is used only to call the API on your behalf and to derive a private account id; it is never shown to anyone.

Claude claude.ai · Desktop

Open Customize → Connectors, then click + Add → Add custom connector.
Enter the name Mercoa and this URL, then click Add:
https://mercoa.usefulapi.io/mcp
Claude opens the login page: enter your Mercoa API key.
In a chat, click + → Connectors and turn on Mercoa.

Team and Enterprise: an Owner adds the connector for the organization first.

ChatGPT chatgpt.com

Open Plugins, click +, then Add custom MCP server.
Enter the name Mercoa and this URL, choose OAuth as the authentication, confirm the warning and create it:
https://mercoa.usefulapi.io/mcp
ChatGPT opens the login page: enter your Mercoa API key.
In Plugins, install Mercoa, then choose it in a chat.

No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.

Claude Code

Run this command, then run /mcp in Claude Code to log in:

claude mcp add --transport http mercoa https://mercoa.usefulapi.io/mcp

Cursor

Add to Cursor or add this to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "mercoa": {
      "url": "https://mercoa.usefulapi.io/mcp"
    }
  }
}

VS Code

Add to VS Code or add this to .vscode/mcp.json:

{
  "servers": {
    "mercoa": {
      "type": "http",
      "url": "https://mercoa.usefulapi.io/mcp"
    }
  }
}

Codex

Run these commands. The second one opens the login page:

codex mcp add mercoa --url https://mercoa.usefulapi.io/mcp

codex mcp login mercoa

Other clients

Windsurf, Cline, Zed and other MCP clients: add this URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser.

https://mercoa.usefulapi.io/mcp

Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Mercoa API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.

Pricing

Plan	Price	Limit
Free	$0	50 tool calls / month
Pro	$9/mo · $90/yr	10,000 tool calls / month
Pro+	$39/mo · $390/yr	100,000 tool calls / month

Each paid plan covers this Mercoa server only. Ask your AI to run mercoa_upgrade and choose Pro or Pro+, billed monthly or yearly (it returns a Stripe Checkout link). If you already have Pro, ask to change it to Pro+. The change requires your confirmation, keeps your billing interval and charges the price difference for the rest of the period immediately. Cancel any time with mercoa_cancel_subscription: your paid plan continues to the end of the paid period, with no refund for the current period, and asking to resume the same plan with mercoa_upgrade before then undoes the cancel. Or write to [email protected].

Tools 21

Show all 21 tools (the AI picks them for you)

Read only · 13

Find entitiesmercoa_find_entities
Find/search entities (buyers, vendors, payors, payees). Use to look up counterparties by name/email/foreignId or list all.
Get entitymercoa_get_entity
Get a single entity by ID (or foreign ID).
Get entity eventsmercoa_get_entity_events
Get the event/audit log for an entity.
Get entity invoice metricsmercoa_get_entity_invoice_metrics
Get aggregate invoice metrics (totals/counts, grouped by currency) for an entity's payables/receivables — for AP/AR dashboards and aging.
List entity payment methodsmercoa_list_entity_payment_methods
List an entity's payment methods (bank accounts, cards, check, etc.).
Get payment methodmercoa_get_payment_method
Get a single payment method for an entity.
List entity usersmercoa_list_entity_users
List the users belonging to an entity (approvers, admins, etc.).
Find invoicesmercoa_find_invoices
Find/search invoices (bills) across payers and vendors. Filter by status, entity, date, approver and more. GET /invoices (plural list endpoint).
Get invoicemercoa_get_invoice
Get a single invoice (bill) by ID.
Get invoice eventsmercoa_get_invoice_events
Get the event/audit log for an invoice (status changes, approvals, payments).
Find transactionsmercoa_find_transactions
List/search payment transactions. Filter by entity, invoice, status, type and date.
Get transactionmercoa_get_transaction
Get a single payment transaction by ID.
Get organizationmercoa_get_organization
Get the caller's Mercoa organization configuration (settings, payment methods enabled, etc.).

Changes data · 4

Create entitymercoa_create_entity
WRITE — creates a real entity (customer/vendor/payor/payee) in Mercoa. Supply role flags, accountType, and a nested `profile` object (business or individual details).
Create invoicemercoa_create_invoice
WRITE — creates a real invoice/bill in Mercoa. Set status (DRAFT to stage, NEW to submit), amount, currency, payer/vendor, dates and line items.
Update invoicemercoa_update_invoice
WRITE — updates an existing invoice/bill (all fields optional). Commonly used to advance status (e.g. DRAFT→NEW→SCHEDULED) or change amounts, dates, or payment methods.
Add invoice commentmercoa_add_invoice_comment
WRITE — adds a comment to an invoice (visible in its activity log).

Your usefulapi plan · 4

Usage status (free-tier meter)mercoa_usage_status
Report the caller's current usage: the plan, calls used this month, the limit of the plan (the free monthly cap or the Pro fair use limit), remaining, and whether the limit is reached. Read-only; does not count against the meter.
Request a missing featuremercoa_request_feature
Tell usefulapi that the user needs something the Mercoa tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter.
Upgrade to Pro or Pro+mercoa_upgrade
Get a paid plan for Mercoa (the free tier caps monthly usage). Pro: 10,000 tool calls a month, for normal use — plan "monthly" ($9/month) or "yearly" ($90/year, 2 months free). Pro+: 100,000 tool calls a month, for automations and heavy use — plan "plus" ($39/month) or "plus_yearly" ($390/year). Without a plan it returns both Pro and Pro+, each with a payment link, for the user to choose; with a plan, one link. An existing Pro subscription changes to Pro+ in place (needs confirm: true; the price difference for the rest of the period is charged at once). Cancel any time: the plan then runs to the end of the paid period, so it also suits a one-time job. A link opens Stripe Checkout in the browser; after payment the account upgrades automatically. Does not count against the meter.
Cancel the Pro subscriptionmercoa_cancel_subscription
Cancel the caller's Mercoa Pro subscription at the end of the paid period (no refund for the current period; Pro continues until then, then the free tier applies). Requires confirm: true. Run mercoa_upgrade later to undo the cancel before the period ends. Does not count against the meter.

FAQ

What can I do with Mercoa in Claude or ChatGPT?

Find bills that wait for approval. See the history of an invoice. Total invoice amounts per entity and currency. Check payment transactions for an invoice or entity. Find or add a vendor or customer. Create a bill, update it or add a comment. See what you can do for the details.

Is this an official Mercoa product?

No. usefulapi is an independent service. It is not affiliated with or endorsed by Mercoa. The server calls the Mercoa API with your own Mercoa access, so it sees only the data that your account can see.

Can I connect Mercoa to Claude or ChatGPT?

Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.

What do I need to connect?

The login page asks for your Mercoa API key. See Before you connect for where to find it.

Do I put my Mercoa key or an Authorization header in the client config?

No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Mercoa API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.

How do you keep my Mercoa credentials?

The login stores them encrypted in the authorization grant of your connection. The server uses them to call the Mercoa API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in Mercoa.

Can the AI change my Mercoa data?

Yes, if you approve it. 4 of the 17 Mercoa tools can create or change data. The other 13 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.

What does it cost?

The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with 10,000 tool calls / month. Pro+ costs $39/mo or $390/yr, with 100,000 tool calls / month. Each subscription covers this Mercoa server only. Cancel any time: your paid plan then runs to the end of the paid period. Run mercoa_usage_status to see how many calls you used.

How do I subscribe or cancel?

Ask the AI to run mercoa_upgrade and choose Pro or Pro+, billed monthly or yearly: it returns a Stripe Checkout link. If you already have Pro, ask to change it to Pro+. After you confirm, your existing subscription changes in place, keeps its billing interval and charges the price difference for the rest of the period immediately. To cancel, run mercoa_cancel_subscription. Your paid plan continues to the end of the paid period.

What if a Mercoa tool that I need is missing?

Tell the AI what you wanted to do. It can send the request with mercoa_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.

Which AI clients can I use?

Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.

This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.

Need a tool this server does not have, or a connection to another system? We build custom integrations and MCP servers.

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