x402 and ERC-8004 protocol reference: worked examples
Protocol Ledger is a free, dated reference for five payment, agent-identity and token interfaces. Each record preserves its official specification, review date and interpretation limits. Filter the same snapshot in the browser or retrieve it through the JSON API.
Three fictional scenarios, calculated by the same engine as the tool. They illustrate behavior and failure cases, not customer outcomes or measured provider performance.
Explore the five profiles
Inspect the scope, version and official source behind each record.
- Profiles
- 5
- Checked at
- 2026-09-19
- Freshness
- Within your age limit
| Profile | Purpose | Status | Version | Source |
|---|---|---|---|---|
| x402 v2 exact EVM | payment | specification | 2 | https://github.com/coinbase/x402/blob/main/specs/x402-specification-v2.md |
| ERC-8004 | identity | draft | EIP-8004 | https://eips.ethereum.org/EIPS/eip-8004 |
| ERC-20 | token | standard | EIP-20 | https://eips.ethereum.org/EIPS/eip-20 |
| ERC-721 | token | standard | EIP-721 | https://eips.ethereum.org/EIPS/eip-721 |
| ERC-1155 | token | standard | EIP-1155 | https://eips.ethereum.org/EIPS/eip-1155 |
Run this scenario Input JSON Calculated report
Inspect every input
{
"purpose": "all",
"status": "all",
"asOf": "2026-09-19",
"maxAgeDays": 30
}Payment integration
Find the dated x402 payment profile.
- Profiles
- 1
- Checked at
- 2026-09-19
- Freshness
- Within your age limit
| Profile | Purpose | Status | Version | Source |
|---|---|---|---|---|
| x402 v2 exact EVM | payment | specification | 2 | https://github.com/coinbase/x402/blob/main/specs/x402-specification-v2.md |
Run this scenario Input JSON Calculated report
Inspect every input
{
"purpose": "payment",
"status": "all",
"asOf": "2026-09-19",
"maxAgeDays": 30
}Check an old snapshot
Move the review date forward and inspect the stale state.
- Profiles
- 5
- Checked at
- 2026-09-19
- Freshness
- Review overdue
| Profile | Purpose | Status | Version | Source |
|---|---|---|---|---|
| x402 v2 exact EVM | payment | specification | 2 | https://github.com/coinbase/x402/blob/main/specs/x402-specification-v2.md |
| ERC-8004 | identity | draft | EIP-8004 | https://eips.ethereum.org/EIPS/eip-8004 |
| ERC-20 | token | standard | EIP-20 | https://eips.ethereum.org/EIPS/eip-20 |
| ERC-721 | token | standard | EIP-721 | https://eips.ethereum.org/EIPS/eip-721 |
| ERC-1155 | token | standard | EIP-1155 | https://eips.ethereum.org/EIPS/eip-1155 |
Run this scenario Input JSON Calculated report
Inspect every input
{
"purpose": "all",
"status": "all",
"asOf": "2026-11-01",
"maxAgeDays": 30
}A mistake worth catching
A current API response can still contain an old research snapshot. Check the original checkedAt and stale fields, not just the request timestamp.
Use the method with your records
Serve a versioned editorial snapshot. Filter by purpose or specification status; preserve source, checked date and unsupported conclusions in every record.
Five initial profiles; no market prices, exhaustive schema coverage, real-time protocol monitoring or paid endpoint.
Read the complete method, sources and input contract. Updated 2026-09-19; by the AGI Scorecard team.