ap2-human-not-present-flow

AP2 Human-Not-Present Transaction Flow

Before writing code

Fetch live docs:

1. Fetch https://ap2-protocol.org/specification/ for the human-not-present flow specification
2. Web-search site:github.com google-agentic-commerce AP2 human-not-present intent mandate for samples
3. Fetch https://ap2-protocol.org/topics/core-concepts/ for flow overview
4. Fetch https://ap2-protocol.org/roadmap/ to check current support level (V0.1 scope)

Conceptual Architecture

What Human-Not-Present Means

In a human-not-present flow, the user provides authorization upfront and then leaves. The Shopping Agent acts autonomously within the constraints defined in the signed Intent Mandate.

Important: Roadmap Status

The AP2 V0.1 specification focuses on human-present scenarios. Human-not-present support is on the V1.x roadmap. Check the latest specification for current support level.

Flow Overview

Phase 1: Intent Capture (User Present)
  1. User → SA:       Expresses shopping intent ("Buy me running shoes under $150")
  2. SA → User:        Repeats back understanding for confirmation
  3. User:             Confirms via in-session authentication
  4. SA:               Creates Intent Mandate from user's expressed intent
  5. User → SA:        Signs the Intent Mandate (hardware-backed)
  6. User:             May go offline

Phase 2: Autonomous Shopping (User Absent)
  7. SA → Merchant:    Presents Intent Mandate
  8. Merchant:         Evaluates whether they can fulfill within constraints
  9. If uncertain →    Merchant may force user confirmation (escalate)
  10. If needs info →  Merchant asks clarification (update Intent Mandate)
  11. If can fulfill → Merchant creates Cart Mandate with offer

Phase 3: Authorization (May Require User)
  12. SA:              Evaluates Cart Mandate against Intent Mandate constraints
  13. If within bounds → SA proceeds with payment
  14. If outside bounds → SA rejects or escalates to user
  15. Payment processing (similar to human-present Phase 4-6)

Key Differences from Human-Present

Aspect	Human-Present	Human-Not-Present
User involvement	Throughout	Only at start (signing)
Primary VDC	Cart Mandate	Intent Mandate
Specificity	Exact items	Categories + constraints
Agent autonomy	Low (user confirms)	High (agent decides within bounds)
Risk level	Lower	Higher (needs more safeguards)

Merchant Escalation Paths

The merchant can escalate from human-not-present to human-present:

1. SKU Selection Required — Merchant has multiple matching products, needs user to choose → becomes human-present Cart Mandate flow
2. Clarification Questions — Merchant needs more information about requirements → Shopping Agent may auto-respond from Intent Mandate or ask user
3. Force User Confirmation — Merchant uncertain about matching, requires explicit human approval → full human-present authorization

Constraint Evaluation

The Shopping Agent must enforce Intent Mandate constraints:

• Price — Is the offer within the authorized price range?
• Category — Does the product match authorized categories?
• Brand — Does the product match brand preferences?
• Quality — Does the product meet quality criteria?
• TTL — Is the Intent Mandate still valid (not expired)?

If any constraint is violated, the agent must:

• Reject the offer
• Try a different merchant
• Or escalate to the user for updated authorization

Natural Language Audit

The Intent Mandate captures the user's actual words:

• "Buy me the cheapest running shoes under $150 in size 10"
• This natural language record provides accountability
• If the agent buys something outside this intent, the record shows the discrepancy

Best Practices

• Capture the user's intent precisely — errors here propagate through the whole flow
• Set conservative TTLs for Intent Mandates
• Always enforce constraint checking before proceeding with payment
• Handle merchant escalation gracefully
• Implement clear logging of agent decisions for audit
• Support the escalation from human-not-present to human-present smoothly
• Notify the user of purchase completion (even though they're not present)
• Check the roadmap — full human-not-present may have limited V0.1 support

Fetch the specification for the current support level and exact Intent Mandate fields before implementing autonomous flows.