Clear customer selection
If there are multiple matches, the plugin asks you to choose a customer.
Public plugin preview
Invoice drafts with Claribill in Codex and ChatGPT
Connect your Claribill account using OAuth, find existing customers and products, and calculate an invoice draft for review. Claribill saves the draft only after you explicitly confirm the summary. Authenticated tool calls are recorded in private API usage logs.
Saved products and services
Products and services are read directly from your connected company.
Check totals first
Net, tax and gross totals are calculated without changing invoice data. The API call is logged.
Confirm before saving
A proof valid for ten minutes binds the exact, unchanged draft shown to you. Saving requires your explicit approval.
Company access controls
The company, user, role and permissions come exclusively from the OAuth grant.
Stays a draft
The plugin does not finalise, send or pay an invoice.
Connect Claribill
Codex and ChatGPT use different connection paths during review. The Plugins switch in the Codex desktop app allows installed plugins; it does not enable ChatGPT developer mode. Once published, Claribill can be installed directly from the shared plugin directory.
Codex: use the installed plugin
- In Codex settings, enable Plugins under General.
- Open Plugins, search for Claribill and enable the installed plugin.
- Start a new task and ask Codex to use Claribill. OAuth sign-in starts with the first tool call.
ChatGPT: connect MCP in your browser
- Open ChatGPT's plugin management in your browser, rather than the Codex desktop settings.
- If available for your account, enable developer mode under Security and sign-in. Availability depends on your account and workspace policy.
- Choose Add and create an MCP connection named Claribill Preview using the URL shown below.
- Check that ten Claribill tools are detected, then start a new chat.
MCP URL for this deployment
https://www.claribill.com/api/mcpAuthorise Claribill
Sign-in and company selection stay with Claribill
Sign in using a magic link when you make the first tool call. Then select one company and confirm access to customers, products and invoice drafts. Switching companies in the dashboard later does not silently change this connection.
You need an eligible role and a Claribill plan with API access. External members cannot connect the plugin in this version.
Example
“Create an invoice draft for Muster GmbH for ten hours of consulting at 150 euros per hour, with 20 percent VAT.”
Codex finds the customer, calculates the draft and shows the customer, line items, due date, currency, and net, tax and gross totals. The draft is saved only after a response such as “Yes, create it as a draft”. You then receive a direct Claribill link.
Available functions
Search customers
Find existing customers by name, email address or customer number.
View customer
Load a customer's details, including their address and payment terms.
Search products
Find active products and services with their price, unit and tax rate.
View product
Load an active product with its price, unit and tax rate.
Calculate draft
Check line items and net, tax and gross totals without saving an invoice.
Create draft
Create exactly one editable invoice draft after explicit confirmation.
View invoice
Reload an accessible invoice using its Claribill ID.
List invoices
Filter accessible invoices by status, customer, document type and date range, without line items.
List credit notes
Filter accessible credit notes by status, customer and date range, without line items.
View credit note
Reload an accessible credit note using its Claribill ID.
Limits and confirmation proofs
MCP calls are limited to 120 requests per minute. OAuth authorisation and token endpoints allow 30 requests per minute. One-time Dynamic Client Registration allows 10 requests per hour.
The confirmationProof returned by prepare_invoice_draft is valid for ten minutes and bound to the exact, unchanged draft shown to you. If the draft changes or the proof expires, call prepare_invoice_draft again.