Connect LetSign to ChatGPT through a Developer Mode connector and your assistant drafts the proposal, the pricing options and the contract from a single conversation - then stages it for your review. Your client opens one link, picks a plan, signs and pays into your own Stripe.
ChatGPT does the thinking, LetSign does the contracting, Stripe does the collecting. You stay in the loop exactly once - at send time.
No SDK, no webhooks, no integration project. The whole setup is one settings switch, two connections and one prompt.
In ChatGPT, open Settings -> Connectors -> Advanced and enable Developer Mode, then click "Create connector" and paste the LetSign remote MCP URL (streamable HTTP, OAuth supported). LetSign is hosted, so the URL is ready to paste. The honest fine print: Developer Mode is required - a standard ChatGPT connector without it will not run the full LetSign toolset - and custom connectors are available on the Plus, Pro, Business and Enterprise plans.
In the LetSign app, connect your own Stripe account once. From then on every payment - one-off, subscription, or save-card-on-file - is collected through your Stripe and lands in your account. LetSign never holds your money.
Talk to ChatGPT the way you would brief a colleague. One proven opener:
"Draft the annual sales retainer for Brightvale Media from yesterday's discovery call - three tiers, the middle one at the number our sales lead quoted - and stage it for my review."
ChatGPT stages the proposal; nothing sends itself. You read it, tweak anything you like (a discount, net-60 terms, a different tier), and press send. The human send-gate is a feature, not a limitation.
Your client opens one public link, chooses between the plans you offered (conditional pricing built in), verifies their email, signs a binding e-signature and pays through your Stripe - in a single sitting. Remember: the sender never signs. The client does.
Prefer Anthropic's assistant? The same stack runs in Claude. Want the contract step inside a no-code workflow? There is a Zapier playbook too.
ChatGPT drafts the whole proposal with up to several plans your client can choose from - three tiers, optional add-ons, the works - straight from your call notes.
"Has Brightvale signed yet?" ChatGPT checks proposal status through the MCP: opened, plan picked, signed, paid - without you opening a dashboard.
Client asks for net-60 or a 10% discount? Tell ChatGPT, and it updates the terms and restages the proposal for your review.
One-off invoices, subscriptions, or save-card-on-file - collected through your own Stripe account at signature time, not weeks later.
And everything ChatGPT does here, you can also do by hand. Every proposal, template and setting is fully editable in the LetSign app - full parity with the MCP. That two-way door is the essence of an agent-native contract: your agent and you work on the same object, and neither is a second-class citizen.
Yes, with one requirement: Developer Mode. In ChatGPT, open Settings, choose Connectors, go to Advanced and enable Developer Mode, then click Create connector and paste the remote MCP URL (streamable HTTP, OAuth supported). Without Developer Mode, standard ChatGPT connectors do not run the full LetSign toolset. Developer Mode is available on the Plus, Pro, Business and Enterprise plans.
No. Enabling Developer Mode and creating the connector are settings screens, not config files. You connect Stripe once inside LetSign, then everything else happens in plain conversation with ChatGPT. And if you ever prefer to work by hand, every proposal and template is fully editable in the LetSign app.
The Free plan is $0 with a 0.20% fee on payments collected through it. The launch plan is $19 per month until October 1, 2026, and that price is locked until October 1, 2028; after launch the standard price is $49 per month. Paid plans pay 0% on payments up to $20,000 per month, then 0.05% above that.
You do. ChatGPT drafts and stages the proposal, but nothing sends itself: a human reviews and presses send. And the sender never signs. Your client opens the link, picks a plan, verifies their email, signs a binding e-signature and pays through your Stripe.
Enable Developer Mode, add the connector, connect Stripe, and let ChatGPT stage the next proposal for your review.
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