The call succeeds. The body is empty.
A 200 with nothing in it still settles the payment. The agent has paid for air and has no one to ask for it back.
Quality control for agent payments
VIGIL watches the endpoints so they don't have to. Every call tested. Every dollar held until it's earned.
Built natively on Base · x402 · ERC-8004
The problem
Today an agent pays first and hopes.
x402 made paying for an API a single HTTP round trip. It did not make the API accountable. Three failures show up constantly, and every one of them costs the agent the full price.
The fields do not match the contract.
The endpoint returns something, but not the shape the agent was promised. Downstream steps fail long after the money has moved.
Quoted 1.00. Charged 1.40.
The 402 said one price. The settlement took another. Without a neutral record, the overcharge is invisible and repeatable.
How it works
Three steps between a 402 and a fair settlement.
VIGIL sits beside the payment, not inside the API. Watchers measure, the chain remembers, escrow enforces.
Step 01 · Watchers probe
Independent Watchers call every endpoint, and pay for it.
Anyone who stakes $VIGIL can run Probes. Probes hit paid x402 endpoints around the clock, exactly like an agent would, and measure four things: uptime, latency, schema validity, and quoted price against charged price. Each result is signed and published onchain as an Attestation.
Step 02 · Scores go onchain
Attestations become one public number per endpoint.
Attestations are aggregated into an Endpoint Score from 0 to 100, weighted by stake and decayed over time, and written to the ERC-8004 reputation registry on Base. Any agent or developer can read it for free before spending a cent.
Step 03 · Escrow releases or refunds
The money waits until the response passes.
An agent routes its x402 payment through the VIGIL Facilitator instead of paying the endpoint directly. USDC sits in escrow while the response is checked for schema, size and deadline. Pass, and the provider is paid. Fail, and the agent is refunded automatically.
Simulator
Run a paid call through escrow.
Six fictional x402 endpoints, live scores, real timing. Pick one, run the call, and watch USDC lock, the response get checked, and the money release or come back. Nothing touches a chain.
VIGIL Facilitator · simulation
Agent 0xA9e1…D4c2(simulated)USDC 100.00
EndpointsScore · Uptime · p50
Call
GET price-oracle.example/v1/price
quote 0.02 USDC · score 96 · Reliable
StateIdle
Agent
Escrow
Provider
schemasizedeadlineprice
0.02 USDC- Agent requests quote
- USDC locked in escrow
- Provider responds
- Check · schema
- Check · size
- Check · deadline
- Check · price
- Release or refund
Escrow
0.00
Released
0.00
Refunded
0.00
Log is empty. Run a call to begin.
Simulation. No transaction is sent.
Watchers
Neutral eyes, with stake behind them.
Watchers are the people and operators who keep the scores honest. They pay for probes with real USDC, sign what they see, and lose stake if they lie.
- Stake
- Bond $VIGIL to register a Watcher key. Stake is what makes an attestation costly to fake.
- Probe
- Run the reference probe against paid x402 endpoints from at least one region, every minute.
- Attest
- Sign each result and publish it onchain. Accepted attestations earn a share of protocol fees.
- Vote
- When a result is contested, staked Watchers settle it by vote, weighted by stake.
- Slashing
- Attestations contradicted by the majority cost the Watcher a fraction of stake.
What a probe measures
| Measure | How | Weight |
|---|---|---|
| Uptime | Did the endpoint answer with a valid 402 and then a response | 30 |
| Latency | Time to first byte and to complete body, per region | 15 |
| Schema validity | Body matches the schema or content type declared in the 402 | 30 |
| Price integrity | Amount charged at settlement equals the quoted amount | 25 |
{
"endpoint": "price-oracle.example/v1/price",
"method": "GET",
"quotedPrice": "0.020000",
"chargedPrice": "0.020000",
"checks": {
"schema": { "pass": true },
"size": { "pass": true, "bytes": 1284 },
"deadline": { "pass": true, "ms": 142 },
"price": { "pass": true }
},
"result": "PASS",
"watcher": "0x51c2…9aE4",
"region": "eu-west",
"block": 24118204,
"timestamp": 1790419200,
"signature": "0x…"
}Token
Not launched. No contract address yet.$VIGIL
A bond, not a payment method. Payments are USDC. $VIGIL is what a Watcher puts at risk to be believed.
Stake to watch
Required to run probes and earn attestation rewards. No stake, no voice in the score.
Vote on disputes
Contested results are settled by staked Watchers. Voting weight follows stake.
Fee share
50% of protocol fees go to active Watchers, in proportion to accepted attestations.
Buyback & burn
The other 50% of fees buy $VIGIL on the open market and burn it.
Why a token at all
Scores are only worth reading if lying about them is expensive. Watchers must have skin in the game so that slashing means something. A signed attestation backed by stake that can be taken away is a claim with a cost attached. Without that bond, a probe result is just a log line, and a colluding Watcher and provider could manufacture reliability out of nothing.
Launch details will be announced only on x.com/VigilOnBase. Any other address is a scam.
Built on Base
Why this chain.
- x402, native
- Base is where agents already pay for APIs with HTTP 402 and USDC. VIGIL slots in as a facilitator, not a new rail.
- Sub-cent fees
- Gas on Base is low enough to write one attestation per paid call, so scores are built from real traffic, not samples.
- ERC-8004 registry
- Scores land in a shared reputation registry any agent framework can read for free, without asking VIGIL.