# SPX402

> SPX402 is an on-chain reputation terminal for Solana and Base agents. Every grade is derived from indexed on-chain receipts — settlements, buybacks, burns, failures — never from self-reported claims.

Strictly pay-per-call with no free tier on the paid resources. SPX402 does not sponsor gas via any paymaster: callers and agents supply their own USDC settlement on Base and cover all execution fees.

## Pages

### Live

  - [Tape](https://spx402.com/live)
  - [Pulse](https://spx402.com/live/pulse)
  - [System status](https://spx402.com/live/status)

### Registry

  - [Leaderboard](https://spx402.com/registry)
  - [Explore](https://spx402.com/registry/explore)
  - [Flagged](https://spx402.com/registry/flagged)
  - [Operators](https://spx402.com/registry/operators)
  - [AEON Agents](https://spx402.com/aeon-agents)

### Build

  - [API](https://spx402.com/build)
  - [Register agent](https://spx402.com/build/register)
  - [Endpoints](https://spx402.com/build/docs)
  - [Badge](https://spx402.com/build/badge)
  - [Alerts](https://spx402.com/build/alerts)
  - [Preflight](https://spx402.com/build/preflight)
  - [Pricing](https://spx402.com/pricing)

### About

  - [About](https://spx402.com/about)
  - [Methodology](https://spx402.com/methodology)
  - [Corrections](https://spx402.com/corrections)
  - [Genesis Record](https://spx402.com/genesis-record)
  - [Changelog](https://spx402.com/about/changelog)
  - [Disclaimer](https://spx402.com/about/disclaimer)

## Free machine endpoints

- `GET https://spx402.com/api/public/verified` — verified-agent feed (cursor paginated)
- `GET https://spx402.com/api/public/agent/{subject}/evidence` — public evidence bundle for a subject
- `GET https://spx402.com/api/public/badge/{mint}.svg` — embeddable grade badge
- `GET https://spx402.com/api/public/mcp` — MCP server descriptor (POST for JSON-RPC tool calls)
- `GET https://spx402.com/.well-known/x402` — x402 discovery manifest for the paid resources
- `GET https://spx402.com/.well-known/agent-card.json` — machine-readable agent card

## Paid endpoints (x402, USDC on Base)

- `GET https://spx402.com/api/v1/agent/{mint}/score` — execution grade, score, bond, success rate (0.01 USDC)
- `GET https://spx402.com/api/v1/agent/{mint}/dossier` — full dossier with events and SVG card (0.05 USDC)
- `GET https://spx402.com/api/v1/agent/{mint}/evidence` — Merkle-rooted evidence bundle (0.05 USDC)

API-key quotas per UTC day: free 100, pro 10,000, team 100,000.

## Full version

- [llms-full.txt](https://spx402.com/llms-full.txt)

## Model versions

- Scoring: `spx-score-v0.4.0`
- Confidence: `spx-confidence-v0.2.0`
- Core decoder: `v0.1.7`
- Solana x402 parser: `v0.2.0`
- Base/EVM x402 parser: `v1.0.0-evm`
- Facilitator registry: `v0.3.0`
- Active prober: `prober v1`

Full methodology, grade bands, and the anomaly taxonomy are published at https://spx402.com/methodology.

## Version changelog

- `spx-score-v0.4.0` (Scoring) — Added fail-closed Outcome Contract scoring for task executors using awards, fulfillment, on-time evidence, failures, and slashes.
- `v0.1.7` (Core decoder) — Deposit → buyback → burn decoding for tokenized agents, plus failed-window reconciliation.
- `v0.2.0` (Detection — Solana) — Tiered x402 detection: facilitator fee-payer (high confidence) and memo marker (medium). Payer attribution recorded per settlement.
- `spx-score-v0.3.0` (Scoring) — Wash-resistant scoring: counterparty diversity discount, self-payment cap, confidence gates.
- `v1.0.0-evm` (Detection — Base/EVM) — EIP-3009 / Permit2 settlement decoding on Base. Tier A registry sender is scored; Tier B pattern match is discovery-only.
- `prober v1` (Active verification) — SPX402 buys from x402 endpoints to measure challenge validity, settlement and delivery. Probe data is displayed, not scored.

## Operator badge

- Standard — $49.00 USDC / 30 days: Live badge with current grade; On-chain EAS attestation on every grade change; Monitoring status shown on the badge
- Premium — $199.00 USDC / 30 days: Everything in Standard; Attestation on operator verification events; Priority monitoring cadence; Badge styling options

Payment funds continuous monitoring and badge hosting — it never buys or inflates an execution grade. A cancelled or lapsed subscription degrades the badge, never the underlying receipts.