Connect LetSign to Windsurf and Cascade drafts the proposal, the pricing options and the contract without leaving your editor - then stages it for your review. Your client opens one link, picks a plan, signs and pays into your own Stripe.
Cascade 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 two connections and one prompt.
Open ~/.codeium/windsurf/mcp_config.json (or, inside Windsurf, go to Manage MCP Servers -> View raw config, which opens the same file) and add a LetSign entry with a "serverUrl" field pointing at the LetSign remote MCP endpoint. Save, and the LetSign tools load straight into Cascade. LetSign is hosted, so there is nothing to run locally - create your free account at app.letsign.ai to get your endpoint.
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 Cascade the way you would brief a teammate in the same repo. One proven opener:
"Cascade, draft the maintenance retainer for Meridian Consulting from the scope of work in this repo - three tiers, the middle one at the number we agreed on the call - and stage it for my review."
Cascade 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.
Working in a different editor? The same stack runs in Cursor and Cline. Living in a chat window instead? There is a Claude playbook too.
Cascade 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 Meridian signed yet?" Cascade 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 Cascade, 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 Cascade 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.
Through its MCP config file. Add an entry with a serverUrl field to ~/.codeium/windsurf/mcp_config.json, or open Manage MCP Servers and choose View raw config to edit the same file from inside Windsurf. Save, and the remote server's tools load straight into Cascade. LetSign is a hosted remote MCP server, so that one entry is all the setup it needs.
No. The whole setup is pasting one small JSON entry - a serverUrl line in mcp_config.json - and Windsurf can open that file for you from Manage MCP Servers. You connect Stripe once inside LetSign, then everything else happens in plain conversation with Cascade. 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. Cascade 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.
Add the config entry, connect Stripe, and let Cascade stage the next proposal for your review.
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