AgentGuard™ Chargeback

Typed, deterministic helper library that assembles chargeback-evidence payloads in the schema expected by the current Stripe Disputes API and stages them with submit:false for human review. Open-source, MIT licensed, self-hosted.

Install

npm install @merchantguard/agentguard-cb

git clone https://github.com/MerchantGuard/agentguard-cb

What it does

• Assembles Stripe Disputes API evidence payloads in Visa CE 3.0 shape from your own product, billing, and support events.
• Stages every submission with submit:false. Your reviewer presses the button.
• Writes an Ed25519-signed, SHA-256 hash-chained audit log on the merchant side.
• Ships an MCP server so Claude Code, Cursor, Codex, or a local LLM (Ollama, LM Studio, Qwen) can drive it.
• Includes a buyer-readable event-log layer (v1.1) that renders the same chain as plain English, CSV, or JSON.

What it does NOT do

• Does NOT file disputes with Visa.
• Is NOT a Visa Third Party Agent under Visa Core Rules § 10.2.2 and is not registered under the Visa TPA Registration Program.
• Has NO contractual or technical relationship with Visa Inc., Stripe, Inc., or any acquirer.
• Does NOT submit on the merchant's behalf. Default submit:false.
• Does NOT invoke any LLM in the evidence pipeline. Static templates only.
• Does NOT guarantee dispute outcomes. CE 3.0 qualification is determined by Visa Resolve Online and the issuing bank.

Quickstart

import {
  evaluateVisaCe3Eligibility,
  buildStripeVisaCe3EnhancedEvidence,
  customerEvidenceBundleSchema,
} from '@merchantguard/agentguard-cb'

const bundle = customerEvidenceBundleSchema.parse(yourBundle)
const eligibility = evaluateVisaCe3Eligibility(bundle)

if (eligibility.qualified) {
  const payload = buildStripeVisaCe3EnhancedEvidence(
    bundle,
    eligibility.selectedPriors,
  )
  // Pass payload to your own Stripe SDK call to dispute.update
  // with submit:false for human review.
}

Subpath imports

• @merchantguard/agentguard-cb/evidence — schemas + CE 3.0 eligibility + payload assembly
• @merchantguard/agentguard-cb/audit — Ed25519 hash-chained audit primitives
• @merchantguard/agentguard-cb/pdf — PDF generation + signed manifest verification
• @merchantguard/agentguard-cb/adapters — EvidenceAdapter interface + reference adapter
• @merchantguard/agentguard-cb/event-log — buyer-readable event log (v1.1)

MCP tools

• evaluate_ce3_eligibility — score a CustomerEvidenceBundle for Visa Compelling Evidence 3.0.
• build_ce3_evidence — assemble the Stripe-shape enhanced_evidence payload.
• canonical_json_hash — canonical JSON serialization + SHA-256 hex digest.
• verify_manifest_signature — verify an Ed25519 signature over a previously-generated PDF manifest.
• append_event (v1.1) — append a typed event to the buyer-readable event log.
• render_event_log (v1.1) — render the chain in plain English, CSV, or JSON.
• verify_chain (v1.1) — walk the chain and report tamper-evidence.
• describe_agentguard_cb — high-level capabilities, safety posture, patent and license status.

Resources

Live page: merchantguard.ai/agentguard-cb
GitHub: github.com/MerchantGuard/agentguard-cb
npm: @merchantguard/agentguard-cb