SapienFuel

Purpose:
Intercept the x402 Paywall via a proxy and enable sponsors to cover payments in exchange for user task execution and/or data provision.
Additionally, sponsors can create and distribute “campaigns,” allowing users to naturally utilize this mechanism through major AI / developer UIs.

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Product Scope

What this product enables

• Provides the following payment methods for access to x402-protected resources (APIs, data, digital content, etc.):
  • Sponsors cover all or part of the payment (in exchange for requesting user tasks or data provision).
  • Users pay directly (fallback).
• Sponsors can issue campaigns defining:
  • Which users to target
  • What they want users to do
  • How much they will subsidize
• Users can select sponsor-backed x402-enabled services based on:
  • Service name, or
  • Desired functionality / features they want agents to use
• Users can store and reuse profiles and survey responses so they don’t have to repeat the same inputs each time.
• When credits run out during agent execution, users can be notified and guided to complete tasks.

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Core Concepts

• Resource: An upstream paid endpoint protected by x402
• Proxy: Intercepts 402 responses and presents the paywall and task flow
• Sponsor: The entity covering the payment (companies, and in the future, agents as well)
• Campaign: A recruitment unit created by sponsors (target, objective, budget, tasks, registration to sponsor services, data requests, consent conditions)
• Offer: Sponsor terms at the resource level (discount rate, cap, required tasks, collected data)
• Action Plugin: An extensible plugin layer for adding tasks or data collection
• Consent Vault: A layer managing explicit consent, usage purpose, retention period, and contact permissions

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Requirements (Prioritized)

P0: Must work first (without breaking upstream compatibility)

• x402 Proxy

  • Proxies requests to upstream x402 resources and displays a paywall upon receiving a 402 response
  • When sponsor payment succeeds, executes payment upstream and returns the resource response to the user

• Paywall UI

  • Displays active sponsor conditions (if any) and allows task selection and execution
  • Clearly indicates the presence of a sponsor to the user

• Action Plugin System

  • Preserves existing actions while allowing additional tasks to be added later
  • Provides a consistent interface for task start / verification / completion

• Resource Discovery

  • Allows users to search and browse available x402 resources

• Direct Payment (Fallback)

  • Maintains a direct payment path if no sponsor is available or if the user declines

• ChatGPT Integration (MCP + Widget)

  • Provides an MCP server enabling Paywall / Resource widget display
  • Maintains direct payment fallback if no sponsor is available or consent is declined

• Claudecode / OpenClaw Integration (MCP + Widget)

  • Provides Skills enabling Paywall / Resource widget display

• Deployment

  • Treats Vercel deployment as first-class; iframe asset loading must not break
  • Required environment variables are documented in the README and deployments are reproducible

Completion Criteria (Minimum)

• End-to-end flow works locally and in production:
  402 → Paywall → Action → Sponsor payment → Resource delivery
• Sponsor display and consent UI are visible and verifiable

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P1: Core additional requirements (product value layer)

ToB: Sponsor Campaign Builder (Chat AI UI)

• Sponsors can create campaigns through natural language Q&A

  • From target attributes, recommended x402-enabled services are ranked and suggested
  • From stated objectives, recommended task sets, subsidy amounts, discount rates, and caps are proposed
  • Creators can publish by selecting proposals

• Sponsor Dashboard

  • Campaign list (status, spend, completion count)
  • Data Inbox (received data count, content review, export)

ToC: Practical user entry points

• Users can search by service name and see sponsor availability

• Users can search by function and choose sponsor-backed tools
  (e.g., scraping, design, storage)

• Profile Vault

  • Stores basic data such as email, region, IP type, and services in use
  • Saves survey responses for reuse during task execution

• Consent / Compliance

  • No data is transferred to sponsors without explicit opt-in consent
  • Usage purpose, retention period, and sponsor contact permissions must be displayed

• Notification

  • When credits are exhausted (e.g., during agent operation), users can be notified and guided to tasks

Completion Criteria (Minimum)

• Sponsors can create and publish campaigns visible in user search and paywalls
• Sponsors can review results in the Data Inbox
• Users can shorten inputs via profile storage and reuse
• Notifications can route users to paywalls

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P2: Scale requirements (longer-term leverage)

• Advanced Recommendation Engine

  • Evolve from rule / tag-based logic to outcome-driven weighting
  • Gradual introduction of embeddings and collaborative filtering

• Fraud / Low-quality mitigation

  • Progressive human verification
  • Stronger task proof mechanisms (external integrations, webhooks, revalidation)

• Multi-client integration expansion

  • Provide a common HTTP API and SDK for clients beyond ChatGPT
    (Claude, Codex, OpenClaw, etc.)
  • Enable completion via “link-based paywalls” even in environments where UI embedding is not possible

• Analytics and audit

  • Funnel tracking (view / start / complete / payment)
  • Sponsor viewing / export audit logs
  • Data redaction and minimization operations

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Data Collection Framework (Provided as Action Plugins)

Basic personal data

• Email
• Region
• IP type
• Optional signup requests to sponsor pages
• Minimum human verification to ensure the user is not a bot

Survey data

• Demographics
• Goals / KPIs
• Organization size
• Prompts (only when necessary)
• Agents / skills usually used
• Media consumption
• Competitor usage
• Satisfaction with current services
• Price sensitivity
• Switching triggers
• Alternative comparisons

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Compliance (Must)

• Explicit user consent
  (manageable at item level and sponsor level)
• Usage purpose disclosure
• Data retention disclosure
• Sponsor contact disclosure
  (user can opt in or opt out)

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Non-Goals (Out of scope for initial phase)

• Full KYC or heavy identity verification
• Advanced recommendation models from the start
  (begin with rules / tags)
• Native UI integrations for all clients from the start
  (absorb via MCP + HTTP first)
• Heavy data infrastructure integrations
  (begin with export + audit logs)

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Suggested Milestones

• M0: End-to-end flow with upstream compatibility (P0)
• M1: Service search, sponsor visibility, real usage routes (P1 ToC first half)
• M2: Campaign Builder Chat, publishing, Data Inbox (P1 ToB)
• M3: Profile Vault + Consent completion (P1 operational requirements)
• M4: Notifications and multi-client API / SDK (P1 latter half)

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