How it works
No jargon version: Harness reads your ledger and your email while you sleep, writes the follow-ups you would have written, and waits for you to approve each one. Here is the whole loop, step by step.
Xero for the ledger, Gmail for the conversations. Each connection uses the app's own sign-in and permission screen. You see exactly what access you are granting, and you can revoke it from the app itself at any time. Harness never sees your passwords.
MCP is the standard way AI tools talk to other software. Your supported ChatGPT or Claude account connects to Harness through it, which means the AI reaches your business data through one controlled door, not a pile of exports and copy-paste. Switch AI provider later and the door stays put: your facts, rules and history live in Harness, not in the chat.
Once a day, Harness reads the ledger and the relevant email threads. It sorts late from not due, checks what was promised and what was paid, and writes a fresh follow-up per invoice in your tone. It also writes your morning summary: what changed, what is overdue, what needs your eyes.
Drafts wait for you to approve, edit or skip. You can let routine reminders send on their own. Every draft sits in a queue you review over coffee, on your phone. Read it, edit it if you like, tap send. The message goes from your own address, as you.
Every approved send, every reply, every promise a customer makes gets noted against the account. Next time that invoice runs late, the draft knows the history: the difficult call on Tuesday, the fact they always pay on the 15th. That memory is yours, and it survives changing AI provider.
Harness reads, drafts and remembers. It does not send, edit, void, pay or delete. Every customer message needs your tap. Every connection can be revoked from the app itself. Your data is never used to train AI models. The exact per-app boundaries are on the Xero and Gmail pages.
No. Never. Every message to a customer waits in your approval queue until you read it and tap send. That is the core rule of the product, not a setting.
MCP is a standard connector that lets an AI chat like ChatGPT or Claude talk to another piece of software through one controlled door. Your AI reaches your business data through Harness, with your rules applied, instead of you pasting ledgers into a chat window.
Your facts, sources, rules, client context and approval log stay in Harness. You connect the new chat through MCP and carry on. The business memory does not reset, because it was never inside the chat.
Inside your Harness account, under the permissions you granted. Your email and ledger data is never used to train AI models, and each connection can be revoked from the app itself at any time.
It cannot send anything on its own, edit or void invoices, touch bank feeds or payroll, or see your passwords. The integration pages for Xero and Gmail spell out the exact boundary for each app.
Seven days free, then £19 a month for your whole company if you are one of the first 50 companies, the Founding Fifty. Connect your apps tonight, read the first drafts tomorrow morning.