acp-affiliate-attribution

name	acp-affiliate-attribution
description	Implement ACP affiliate attribution — privacy-preserving affiliate tracking without cookies using token-based first-touch and last-touch attribution. Use when building affiliate programs, referral tracking, or partnership attribution.

ACP Affiliate Attribution

Before writing code

Fetch live docs:

1. Web-search site:github.com agentic-commerce-protocol rfcs affiliate_attribution for the affiliate attribution RFC
2. Fetch https://developers.openai.com/commerce/specs/checkout/ for how attribution integrates with checkout
3. Web-search site:github.com agentic-commerce-protocol spec json-schema affiliate for the schema

Conceptual Architecture

What Affiliate Attribution Does

ACP's affiliate attribution extension provides privacy-preserving affiliate tracking without cookies. It replaces traditional cookie-based tracking with structured tokens that respect buyer privacy while enabling fair commission attribution.

Key Properties

• Write-only — Attribution data is sent to the merchant but NEVER echoed back in responses. This prevents information leakage.
• Privacy-preserving — No third-party cookies, no cross-site tracking, no browser fingerprinting
• Token-based — Attribution uses opaque tokens rather than personally identifiable data
• Two attribution models: First-touch and last-touch

Attribution Models

Model	Description
First-touch	Credit goes to the first affiliate that referred the buyer
Last-touch	Credit goes to the most recent affiliate before purchase

How It Works

1. Affiliate generates a tracking token (opaque identifier)
2. When buyer clicks affiliate link, the agent receives the attribution token
3. Agent includes first-touch attribution data on create (POST /checkout_sessions) and last-touch attribution data on complete (POST /checkout_sessions/{id}/complete)
4. Merchant receives attribution and records it for commission processing
5. Merchant NEVER returns attribution in responses (write-only)

Data Flow

Affiliate → Token → Agent → Checkout Session (attribution field) → Merchant
                                                                      ↓
                                                              Commission Processing

Privacy Compliance

• No PII in attribution tokens
• Tokens are opaque — cannot be reverse-engineered to identify individuals
• Write-only prevents downstream data leakage
• Compliant with GDPR/CCPA by design
• No cross-session tracking without buyer consent

Extension Negotiation

Like all extensions, affiliate attribution must be negotiated:

1. Agent includes affiliate_attribution in capabilities.extensions[]
2. Merchant confirms support
3. Only then is attribution data included in requests

Use Cases

• Affiliate marketing programs
• Influencer referral tracking
• Partnership commission attribution
• Referral program management
• Marketing channel attribution

Best Practices

• Generate unique, opaque tokens per affiliate
• Support both first-touch and last-touch models
• Process attribution asynchronously — don't block checkout
• Never echo attribution data in responses (enforce write-only)
• Build commission reports from stored attribution data
• Test with multiple attribution scenarios (direct, single affiliate, multiple affiliates)

Fetch the affiliate attribution RFC for exact token format, attribution object structure, and write-only enforcement rules before implementing.