n8n Webhook: Claude Text & Image Gen with Stripe Metered Billing

Control Claude Text & Image Generation with Stripe Metered Billing

This n8n workflow exposes a secure POST webhook that authenticates requests with Stripe customer metadata, enforces metered subscription limits, generates content with Anthropic Claude (text) or a configurable image-generation HTTP endpoint (images), records usage in Stripe, and returns a synchronous JSON response.

What this workflow does

• Receives a POST webhook with an apiKey, contentType (text or image), a prompt, and optional generation parameters.
• Authenticates against Stripe by searching for a Stripe customer whose metadata.apiKey matches the incoming key. If no customer is found, it returns a 401 JSON error.
• Validates subscription + metered usage by retrieving the customer’s active Stripe subscription and reading the metered subscription item’s current-period usage summaries.
• Enforces plan limits using the subscription’s Stripe price ID to determine the per-plan monthly cap. If there’s no active subscription or the limit is exceeded, it returns a 402 JSON error.
• Generates output:
  • Text: calls the Anthropic Messages API.
  • Images: calls a configured image-generation HTTP endpoint.
• Records Stripe usage by incrementing the metered subscription item and returns a success JSON payload including the generated content and updated usage counters.

Use cases

• SaaS operators offering API-based AI generation with pay-per-use limits.
• Teams building a “Claude-powered” feature where every request must be billed via Stripe metered subscriptions.
• Automation engineers creating a webhook-based content service that immediately responds with generated text or images.

Technical details

• Webhook: POST endpoint accepting apiKey, contentType, and prompt.
• Integrations: Stripe (Customers, Subscriptions, Subscription Items, Usage Records) + Anthropic Claude (Messages API) + an external image-generation HTTP API.
• n8n nodes used: if, set, code, merge, switch, webhook.

Best for teams who need Claude text & image generation tightly coupled to Stripe billing, limits, and usage tracking.