Tool Index

Payment webhook tools for the work before checkout goes live.

Browser-only utilities for generating fake Lemon Squeezy and Stripe fixtures, producing PayPal live checkout reports, planning production checkout readiness, mapping webhook event coverage, checking HMAC signatures, debugging signature mismatches, producing checkout smoke test reports, deriving idempotency keys, mapping entitlement decisions, calculating debugging cost, replaying webhook requests, assembling launch evidence, checking Pro Kit fit, and deciding whether the Pro Kit is worth buying.

Evidence pack

Billing webhook launch evidence pack

Follow one purchase-adjacent path through checkout smoke, event coverage, fulfillment proof, refund rollback, delivery email, free sample, and CN¥69 Pro Kit review.

Open evidence pack
PayPal live checkout

Lemon Squeezy PayPal live checkout report

Generate a secret-free report for PayPal visibility, CN¥69 price, paid webhook delivery, signature verification, duplicate replay, private delivery, refund rollback, support, and owner approval.

Open PayPal report
Production gate

Lemon Squeezy production checkout readiness report

Generate a secret-free go-live report for live key setup, published variant, CN¥69 price, PayPal checkout, signed paid webhooks, duplicate replay, private delivery, refund rollback, support, and release evidence.

Open readiness report
Live command

Lemon Squeezy live checkout launch command builder

Generate a secret-safe production launch command for CN¥69 price, live store ID, variant ID, publish confirmation, GitHub Pages deployment, and revenue verification.

Build launch command
Launch lane

Lemon Squeezy checkout smoke test report

Start here when the buy link is close. Generate a release-ready report for CN¥69 price visibility, checkout URL, paid webhook delivery, signature gate, duplicate replay, fulfillment evidence, and rollback notes.

Open smoke report
Endpoint smoke

Lemon Squeezy webhook endpoint smoke test

Generate a secret-free endpoint report for webhook URL, POST method, live/test alignment, subscribed events, 2xx response, x-signature checks, retries, and routing.

Open endpoint test
Mode mismatch

Lemon Squeezy live/test mode checker

Generate a secret-free alignment report for checkout links, variants, stores, webhook endpoints, signing secrets, order payloads, and fulfillment routes.

Open mode checker
Delivery proof

Lemon Squeezy fulfillment checklist generator

Prove what happens after payment: signed paid event, live variant match, private ZIP or license delivery, idempotency guard, checksum evidence, support policy, and rollback notes.

Open fulfillment report
No-download incident

Lemon Squeezy paid order delivery incident report

Generate a secret-free incident report for paid checkout, order_created delivery, variant mapping, fulfillment status, private resend, checksum evidence, and refund boundaries.

Open incident report
Refund rollback

Lemon Squeezy refund rollback report

Generate a PR-ready refund evidence report for signed refund events, entitlement rollback, duplicate replay safety, support notes, and secret-free release review.

Open refund report
Event coverage

Lemon Squeezy webhook event coverage matrix

Choose the Lemon Squeezy events your billing route must subscribe to for digital downloads, subscriptions, license keys, signed verification, idempotency, and duplicate replay tests.

Open event matrix
Vercel debug

Vercel Lemon Squeezy webhook debugger

Turn Vercel 404, 405, 500, missing order_created, and invalid x-signature symptoms into a PR-ready Next.js launch report without uploading logs or secrets.

Open Vercel debugger
Search router

Lemon Squeezy webhook troubleshooting hub

Jump from webhook not firing, Vercel 404, Next.js 405, x-signature invalid, checkout 404, PayPal live checks, and production launch symptoms to the right tool.

Pick troubleshooting path
Buyer email

Lemon Squeezy delivery email template generator

Draft buyer-facing delivery, resend, and support emails with private ZIP safety, checksum evidence, support policy links, refund boundaries, and no public secret leakage.

Open email templates
Launch score

Billing webhook launch readiness scorecard

Score raw-body signatures, idempotency, duplicate replay, fixtures, entitlement rules, env secrets, CI, monitoring, and checkout smoke evidence before real payments go live.

Open scorecard
Test plan

Payment webhook test plan generator

Generate a PR-ready plan for provider events, raw-body signatures, trusted fields, idempotency, duplicate replay, entitlement decisions, checkout smoke tests, fulfillment, refunds, and CI.

Open test plan
Buy decision

Billing webhook debug cost calculator

Estimate avoidable debugging exposure and compare it against the CNY 69 Pro Kit reference price before spending more time hand-assembling fixtures and review notes.

Open cost calculator
Provider choice

Checkout provider decision matrix

Compare Lemon Squeezy, Stripe, Paddle, and Polar for an AI SaaS launch, then export a webhook test plan for signatures, idempotency, checkout smoke, fulfillment, and refunds.

Open provider matrix
Pro fit

BillingWebhookKit Pro fit checker

Score launch stage, provider coverage, manual setup time, and webhook risks to decide whether free tools are enough or the CN¥69 Pro Kit is reasonable.

Open fit checker
Fixture generator

Lemon Squeezy webhook payload generator

Generate fake `order_created`, subscription, cancellation, payment, and license payloads with local HMAC signatures and cURL replay commands.

Open payload generator
Signature checker

Lemon Squeezy x-signature verifier

Paste a raw body, endpoint signing secret, and received `x-signature` header to verify whether the digest matches locally.

Open verifier
Mismatch debug

Webhook signature mismatch debugger

Diagnose raw-body mutation, header format, wrong secret, JSON reserialization, CRLF, and framework parser causes behind invalid signatures.

Open mismatch debugger
Retry safety

Webhook idempotency key generator

Build stable provider keys, SQL constraints, handler guards, duplicate replay tests, and review notes before payment side effects run.

Open idempotency tool
Stripe fixtures

Stripe webhook fixture generator

Generate fake Stripe checkout, invoice, subscription, and payment intent payloads with local Stripe-Signature headers and cURL replay commands.

Open Stripe generator
Replay commands

Webhook replay cURL generator

Generate replayable cURL commands and provider signature headers for Lemon Squeezy, Stripe, Paddle, and Polar webhook routes.

Open replay tool
Route generator

Next.js webhook handler generator

Generate App Router handlers with raw-body signature checks, idempotency guard notes, env checklists, and duplicate replay tests.

Open Next.js generator
Next.js raw body

Next.js Lemon Squeezy raw body audit

Score a Next.js App Router Lemon Squeezy route for request.text(), x-signature verification, runtime choice, idempotency, replay tests, and PR evidence.

Open raw-body audit
Vercel debug

Vercel Lemon Squeezy webhook debugger

Diagnose Vercel and Next.js Lemon Squeezy webhook launch failures: 404, 405, 500, missing delivery, raw body, env vars, and release evidence.

Open Vercel debugger
Access rules

Webhook entitlement decision matrix

Generate provider-specific access decisions, persistent writes, and duplicate replay tests for SaaS billing events before checkout opens.

Open matrix generator
Provider choice

Checkout provider decision matrix

Generate a local Lemon Squeezy vs Stripe vs Paddle vs Polar launch test plan for AI SaaS checkout decisions.

Open provider matrix
Debug cost

Billing webhook debug cost calculator

Estimate raw-body, retry, idempotency, entitlement, and release-review debugging cost against a CNY 69 Pro Kit reference price.

Open cost calculator
Pro fit

BillingWebhookKit Pro fit checker

Generate a local recommendation for free tools, missing launch evidence, or the CN¥69 Pro Kit based on webhook launch risk.

Open fit checker
Launch score

Billing webhook launch readiness scorecard

Score raw-body signatures, idempotency, duplicate replay, fixtures, entitlement rules, env secrets, CI, and monitoring before real checkout.

Open scorecard
Checkout proof

Lemon Squeezy checkout smoke test report

Generate a release-ready report for product price, checkout URL, paid webhook delivery, signature gate, duplicate replay, and fulfillment evidence.

Open smoke report
PayPal live checkout

Lemon Squeezy PayPal live checkout report

Generate a launch evidence report for PayPal visibility, CN¥69 price, paid webhooks, x-signature verification, duplicate replay, private fulfillment, and rollback.

Open PayPal report
Production gate

Lemon Squeezy production checkout readiness report

Generate a PR-ready go-live report for live config, CN¥69 price, PayPal checkout, signed webhooks, duplicate replay, delivery, refund rollback, and support.

Open production report
Live command

Lemon Squeezy live checkout launch command builder

Generate the owner-only launch command with safe placeholders for live key, store ID, variant ID, CN¥69 price, publish confirmation, and revenue verification.

Build launch command
Delivery proof

Lemon Squeezy fulfillment checklist generator

Generate a release-ready report for paid order fulfillment, private ZIP delivery, x-signature verification, idempotency, checksum evidence, and support policy links.

Open fulfillment report
No-download incident

Lemon Squeezy paid order delivery incident report

Generate secret-free Markdown evidence for paid orders where download delivery, private resend, checksum proof, or refund boundaries need review.

Open incident report
Refund rollback

Lemon Squeezy refund rollback report generator

Generate secret-free Markdown evidence for refund webhook signature gates, entitlement revocation, duplicate replay safety, and support review.

Open refund report
Buyer email

Lemon Squeezy delivery email template generator

Generate copy-ready delivery, resend, and support replies for paid Lemon Squeezy digital products without exposing private links, API keys, or customer data.

Open email templates
Event coverage

Lemon Squeezy webhook event coverage matrix

Generate a release-ready event subscription matrix for order_created, subscriptions, license keys, paid-state checks, x-signature verification, and duplicate replay coverage.

Open event matrix
Full workbench

BillingWebhookKit browser app

Use the larger workbench for fixtures, signature mismatch debugging, idempotency keys, contract tests, entitlement decisions, replay simulation, cost estimates, and review reports.

Open full app
Privacy Browser-only, no uploaded secrets
Cost No paid provider API calls
Checkout Public Pro checkout still awaiting live key
Package Free sample plus CN¥69 Pro Kit preview

From tool to package

Use the tools first, then copy the tested structure when launch risk rises.

The public tools solve one-off verification jobs. The free sample shows the package format. The Pro Kit adds provider fixtures, route handlers, CI tests, review templates, and launch runbooks for teams preparing to accept real payments.