x402 List

x402 Protocol Service Directory

SYNTHORA Slippage Oracle

Finance PAYMENT-READY imported

payment-ready until 2026-08-20

imported from the x402 Bazaar, not submitted by the operator · own this service? claim it · or ask to be removed

Pre-trade slippage estimate for a Uniswap v3 swap on Base, returning expected output and price impact for a token pair, amount and fee tier. Note: on free-tier testing it returned no quote for major pairs.

Pay from $0.10 per request in USDC on Base, settled onchain via the x402 protocol, no signup, no API key needed.

first settlement 2026-06-29 · $0.05 all-time · settled via coinbase, payAI

BASE URL https://slippage.hergertsynthora.com ENDPOINTS 1 NETWORK Base ASSET USDC MEMBER SINCE 2026-07-20 MONITORED SINCE 2026-07-20

ASSESSMENT

updated 3h ago

Evidence-backed signals, not a single score. Click any chip for the proof. Measured values stay read-only; unknown is honest.

reliability 83.9%
uptime 24h
100%
uptime 7d
90.6%
uptime 30d
83.9%
uptime 90d
83.9%
response p95
2268ms
avg response
1055ms
total checks
1,505

Measured on the unpaid 402 handshake, not the paid call. A service can 402 correctly and still fail after payment.

compliance A (14/14)

14 of 14 x402 conformance checks pass. Full checklist below.

jump to compliance checklist

price $0.10 (p88 in Finance)
price (min)
$0.10
category percentile (min)
p88 in Finance
endpoints / prices
1 / 1
model
flat
stability
0%
risk clean

No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.

domain age
-
registrar
-
hosting
custom
domain created
---

Identity facts, not a risk score.

traction $0.0225606061 30d · 11 buyers
volume 30d
$0.0225606061
buyers 30d
11
settlements 30d
103
first settlement
2026-06-29
last settlement
2026-08-13
top buyer share
85% of 30d volume
trend 7d vs 30d
3.93x the 30d daily rate
networks
eip155:8453
volume all-time
$0.05
settlements all-time
232
median settlement 30d
$0.001
max settlement 30d
$0.10
settled via
coinbase ($1.44, 102 tx), payAI ($0.05, 1 tx)

Attributed pro-quota: this payout address is shared, so volume is the operator-level figure divided by the services sharing it, while buyer and transaction counts stay whole. A declared convention, not an individually observed measure, and still a conservative undercount.

Currently sharing this payout address with Agent Card Validator (A2A), Crypto 24h Trading Stats (Binance data), Crypto Fear & Greed Index, Crypto OHLCV Candles (Binance data), DEX Token Price (GeckoTerminal data), Email Deliverability Audit (SPF, DKIM, DMARC), FX Exchange Rates (ECB), German VAT Number Validator (SYNTHORA), Global Crypto Market Stats (CoinGecko data), Hyperliquid Perps Snapshot, iCalendar (.ics) Generator, LEI Lookup (GLEIF), Order Book Liquidity (Binance depth), Perp Funding Rates (Binance data), Polymarket Prediction Markets Feed, Public Holidays API (Nager.Date), SYNTHORA Address Risk Screen, SYNTHORA Agent Capability Attestation, SYNTHORA Agent Pre-Trade Safety, SYNTHORA AML Wallet Screen, SYNTHORA Base Block Metrics, SYNTHORA BIC/SWIFT Check, SYNTHORA Bridge Risk Evaluator, SYNTHORA Contract Code Check (eth_getCode), SYNTHORA Contract Guard, SYNTHORA Contract Watch, SYNTHORA Counterparty Risk Verdict, SYNTHORA Crypto News Sentiment, SYNTHORA DeFi Data (Hyperliquid perp feed), SYNTHORA DeFi Strategy Verdict, SYNTHORA Derivatives Intel Bundle, SYNTHORA DNS + WHOIS Domain Report, SYNTHORA ENS Resolver, SYNTHORA ERC-20 Token Balance, SYNTHORA Forex Rates (ECB), SYNTHORA FX Exchange Rates, SYNTHORA Gas & MEV Oracle, SYNTHORA IBAN Check, SYNTHORA Inference Router, SYNTHORA Keyless Web Search, SYNTHORA Liquidation Risk Signal (Aave v3), SYNTHORA Mailcheck, SYNTHORA MCP Server Security Scan, SYNTHORA MEV Exposure Detector, SYNTHORA MTA-STS Audit, SYNTHORA Native Balance (eth_getBalance), SYNTHORA Open Interest Oracle, SYNTHORA Pre-Sign Transaction Verdict, SYNTHORA Routing Check, Synthora RPC Contract Metadata, SYNTHORA RPC Network Metadata, SYNTHORA RPC Proxy Detect, SYNTHORA RPC Receipt, SYNTHORA RPC Transaction by Hash, SYNTHORA Stablecoin Peg Monitor, SYNTHORA Stablecoin Supply, SYNTHORA Token Risk, SYNTHORA Translate, SYNTHORA Trending Coins, SYNTHORA Tx Intent Classifier, SYNTHORA Wallet Reputation Score, SYNTHORA x402 Endpoint Preflight, SYNTHORA x402 Registry Watch, VIN Decoder (NHTSA vPIC), Wikipedia Article Summary.

Top buyer share is a concentration signal, not part of the ranking score.

CHANGES

1 event, detecting since 2026-07-24

Payout, price, and schema changes detected on this service's x402 wire. A payout rotation at an unchanged price shows up here even when nothing else moves. Full feed at /changes.

changes schema changed 17h ago (1 since 2026-07-24)

schema changed · 17h ago

schema removed POST /service exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 USDC 2 application/json 300 https://slippage.hergertsynthora.com/service {"name":"USD Coin","version":"2"}

schema added POST /service exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 USDC 2 application/json 300 https://api.hergertsynthora.com/v1/slippage {"name":"USD Coin","version":"2"}

see all changes for this service

WHAT IT DOES

ai-derived

No AI synthesis has been produced for this service yet.

ENDPOINTS

Service endpoints with HTTP method, path, description, pricing, and network
METHOD PATH DESCRIPTION PRICE NETWORK ASSET 402 CHANNEL
POST /service SYNTHORA Slippage Oracle $0.10 Base USDC header
1 endpoints

REQUEST / RESPONSE EXAMPLE

An unpaid request to POST /service returns HTTP 402 with the payment terms. Settle onchain via your facilitator, then retry with the X-Payment header.

// request
curl -i -X POST 'https://slippage.hergertsynthora.com/service'
// 402 response (captured by monitor) · 1 payload · click to expand
[
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x10800a5a5B9d72251566EC651E862A8b4B427dE0",
        "amount": "100000",
        "scheme": "exact",
        "network": "eip155:8453",
        "mimeType": "application/json",
        "resource": "https://api.hergertsynthora.com/v1/slippage",
        "description": "Slippage and price-impact oracle for any crypto pair: estimates expected slippage, price impact and effective execution price for a given trade size from live order-book depth and liquidity. Answers 'expected slippage for this swap', 'price impact of my order', 'orderbook liquidity / slippage', 'how much will I move the market' for execution and routing agents. Deterministic, Ed25519-signed. $0.001 USDC via x402 on Base. First 3 calls FREE per wallet — send header X-WALLET: 0x<your Base address>. No charge on upstream failure. SYNTHORA.",
        "maxAmountRequired": "100000",
        "maxTimeoutSeconds": 300
      }
    ],
    "freeTier": {
      "note": "send header X-WALLET: 0x<your Base address> for a free trial",
      "header": "X-WALLET",
      "callsPerWallet": 3
    },
    "resource": {
      "url": "https://api.hergertsynthora.com/v1/slippage",
      "iconUrl": "https://api.hergertsynthora.com/icon.svg",
      "mimeType": "application/json",
      "description": "Slippage and price-impact oracle for any crypto pair: estimates expected slippage, price impact and effective execution price for a given trade size from live order-book depth and liquidity. Answers 'expected slippage for this swap', 'price impact of my order', 'orderbook liquidity / slippage', 'how much will I move the market' for execution and routing agents. Deterministic, Ed25519-signed. $0.001 USDC via x402 on Base. First 3 calls FREE per wallet — send header X-WALLET: 0x<your Base address>. No charge on upstream failure. SYNTHORA.",
      "serviceName": "SYNTHORA"
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "chain": "base",
              "fee_tier": 500,
              "token_in": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
              "amount_in": 1000000,
              "token_out": "0x4200000000000000000000000000000000000006"
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "ok": true,
              "niche": "slippage_oracle",
              "result": {},
              "receipt": {}
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "method",
                "bodyType",
                "body"
              ],
              "properties": {
                "body": {
                  "type": "object",
                  "required": [
                    "chain"
                  ],
                  "properties": {
                    "chain": {
                      "type": "string"
                    },
                    "fee_tier": {
                      "type": "integer"
                    },
                    "token_in": {
                      "type": "string"
                    },
                    "amount_in": {
                      "type": "integer"
                    },
                    "token_out": {
                      "type": "string"
                    }
                  }
                },
                "type": {
                  "type": "string",
                  "const": "http"
                },
                "method": {
                  "enum": [
                    "POST",
                    "PUT",
                    "PATCH"
                  ],
                  "type": "string"
                },
                "bodyType": {
                  "enum": [
                    "json",
                    "form-data",
                    "text"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            },
            "output": {
              "type": "object",
              "required": [
                "type"
              ],
              "properties": {
                "type": {
                  "type": "string"
                },
                "example": {
                  "ok": {
                    "type": "boolean"
                  },
                  "type": "object",
                  "niche": {
                    "type": "string"
                  }
                }
              }
            }
          }
        }
      },
      "delivery": {
        "note": "unlike the signature -- which you verify BEFORE paying -- this one is checked afterwards, on-chain, from your own wallet",
        "order": "compute -> failure gate -> verify -> settle -> deliver",
        "scope": "this covers service FAILURE, not verdict quality",
        "policy": "no-charge-on-service-failure",
        "verify": "after a request of yours FAILS, check your own wallet on Base: no USDC settlement to our payTo will exist for it. If we had charged you, the transfer would be public and permanent",
        "behaviour": "if the service FAILS (invalid input, timeout, stale cache, withdrawn product, malformed output) you receive 402 and are NOT charged"
      },
      "signature": {
        "alg": "ed25519",
        "canon": "json:sort_keys+separators(,:)+ensure_ascii+utf8",
        "verify": "recompute canon from envelope.result, then VerifyKey(bytes.fromhex(pubkey)).verify(canon, bytes.fromhex(sig)) -- no name to trust, verify the signature yourself",
        "jwksUrl": "https://api.hergertsynthora.com/.well-known/jwks.json",
        "envelope": "{result, attestation:{alg,pubkey,sig,canon}}",
        "sigEncoding": "hex(64B raw)",
        "publicKeyUrl": "https://api.hergertsynthora.com/pubkey"
      }
    },
    "x402Version": 2
  }
]

OVER TIME

All charts use the 30d selector; each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/synthora-slippage-oracle/price, /scores, /volume and /buyers. On-chain volume and distinct buyers are measured over the service's settlement address and are a conservative undercount (only settlements that reach a measured facilitator are counted). The on-chain series roll up hourly, so the latest day can be up to about an hour behind; distinct buyers are counted per payout address, so a service that settles to more than one address is an upper bound.

UPTIME
07-31 · uptime 73.3% · 621ms avg08-02 · uptime 38.9% · 792ms avg08-03 · uptime 0.0%08-04 · uptime 0.0%08-05 · uptime 0.0%08-06 · uptime 0.0%08-07 · uptime 0.0%08-08 · uptime 0.0%08-09 · uptime 0.0%08-10 · uptime 0.0%08-11 · uptime 94.9% · 473ms avg07-20 · uptime 100.0% · 1096ms avg07-21 · uptime 95.6% · 1757ms avg07-22 · uptime 95.6% · 1092ms avg07-23 · uptime 97.8% · 2179ms avg07-24 · uptime 95.6% · 1981ms avg07-25 · uptime 100.0% · 861ms avg07-26 · uptime 100.0% · 692ms avg07-27 · uptime 100.0% · 895ms avg07-28 · uptime 100.0% · 810ms avg07-29 · uptime 100.0% · 784ms avg07-30 · uptime 98.9% · 804ms avg07-31 · uptime 73.3% · 621ms avg08-01 · uptime 100.0% · 664ms avg08-02 · uptime 38.9% · 792ms avg08-03 · uptime 0.0%08-04 · uptime 0.0%08-05 · uptime 0.0%08-06 · uptime 0.0%08-07 · uptime 0.0%08-08 · uptime 0.0%08-09 · uptime 0.0%08-10 · uptime 0.0%08-11 · uptime 94.9% · 473ms avg08-12 · uptime 100.0% · 990ms avg08-13 · uptime 100.0% · 917ms avg07-2008-13
30d UPTIME 84%
RESPONSE TIME
07-20 · 1096ms avg07-20 · 1096ms avg07-21 · 1757ms avg07-21 · 1757ms avg07-22 · 1092ms avg07-22 · 1092ms avg07-23 · 2179ms avg07-23 · 2179ms avg07-24 · 1981ms avg07-24 · 1981ms avg07-25 · 861ms avg07-25 · 861ms avg07-26 · 692ms avg07-26 · 692ms avg07-27 · 895ms avg07-27 · 895ms avg07-28 · 810ms avg07-28 · 810ms avg07-29 · 784ms avg07-29 · 784ms avg07-30 · 804ms avg07-30 · 804ms avg07-31 · 621ms avg07-31 · 621ms avg08-01 · 664ms avg08-01 · 664ms avg08-02 · 792ms avg08-02 · 792ms avg08-03 · 0ms avg08-03 · 0ms avg08-04 · 0ms avg08-04 · 0ms avg08-05 · 0ms avg08-05 · 0ms avg08-06 · 0ms avg08-06 · 0ms avg08-07 · 0ms avg08-07 · 0ms avg08-08 · 0ms avg08-08 · 0ms avg08-09 · 0ms avg08-09 · 0ms avg08-10 · 0ms avg08-10 · 0ms avg08-11 · 473ms avg08-11 · 473ms avg08-12 · 990ms avg08-12 · 990ms avg08-13 · 917ms avg08-13 · 917ms avg07-2008-13
AVG RESP 1056ms
PRICE (captured 402, USD)
07-20 · $0.00108-11 · $0.1008-13 · $0.10$0.1007-2008-13
SUB-SCORES (uptime + x402 compliance)
07-20 compliance: 100% checks07-21 uptime: 95.7% compliance: 100% checks07-22 uptime: 95.7% compliance: 100% checks07-23 uptime: 96.4% compliance: 100% checks07-24 uptime: 96.2% compliance: 100% checks07-25 uptime: 96.8% compliance: 100% checks07-26 uptime: 97.4% compliance: 100% checks07-27 uptime: 97.8% compliance: 100% checks07-28 uptime: 98.1% compliance: 100% checks07-29 uptime: 98.3% compliance: 100% checks07-30 uptime: 98.4% compliance: 100% checks07-31 uptime: 96.1% compliance: 100% checks08-01 uptime: 96.4% compliance: 100% checks08-02 uptime: 92.3% compliance: 100% checks08-03 uptime: 87.1% compliance: 100% checks08-04 uptime: 83.5% compliance: 100% checks08-05 uptime: 83.3% compliance: 100% checks08-06 uptime: 82.9% compliance: 100% checks08-07 uptime: 82.7% compliance: 100% checks08-08 uptime: 82.4% compliance: 100% checks08-09 uptime: 82.2% compliance: 100% checks08-10 uptime: 81.9% compliance: 100% checks08-11 uptime: 82.3% compliance: 100% checks08-12 uptime: 83.1% compliance: 100% checks08-13 uptime: 83.9% compliance: 100% checksuptimecompliance07-2008-13

checklist grew 11->14 on 2026-07-28; a step here is a metric change, not a regression

PILLARS OVER TIME (measured)

Measured site and economics pillars from the assessment history, so the latest value shown elsewhere on this page reads as a point on a trend rather than a permanent state.

VOLUME (on-chain settlement, USD)
07-15 · $0.0007-16 · $0.0107-18 · $0.0207-19 · $0.0007-20 · $0.0107-21 · $0.0107-22 · $0.0107-23 · $0.0007-24 · $0.0107-25 · $0.0107-26 · $0.0407-27 · $0.0107-30 · $0.0008-12 · $108-13 · $0.42peak $107-1508-13

Shared payout address (65 other services). These bars are the full shared address (operator-level), so do not sum them across the services that share it. Where a per-service figure is attributed, the assessment block and the ranking, it is the address total divided pro-quota by the 66 services sharing it: a declared convention, not an individually observed measure.

DISTINCT BUYERS
07-15 · 3 buyers07-16 · 2 buyers07-18 · 2 buyers07-19 · 1 buyer07-20 · 2 buyers07-21 · 2 buyers07-22 · 1 buyer07-23 · 1 buyer07-24 · 1 buyer07-25 · 1 buyer07-26 · 2 buyers07-27 · 1 buyer07-30 · 1 buyer08-12 · 1 buyer08-13 · 3 buyerspeak 3 buyers07-1508-13

Shared payout address (65 other services). These bars are the full shared address (operator-level), so do not sum them across the services that share it. Per-service buyer and transaction counts are shown whole (integers), not divided; only volume is attributed pro-quota. A declared convention, not an individually observed measure.

COMPLIANCE

14/14 checks pass · grade A

last 402 captured 2026-08-12 · last up 2026-08-13

  • 402 payload captured
  • accepts[] array present
  • payTo address recoverable
  • payTo at accepts[0].payTo (conformant shape)
  • payTo is a valid on-chain address
  • atomic price declared
  • atomic price in a sane range
  • asset (token) address declared
  • network resolves to CAIP-2
  • payment scheme declared
  • served over HTTPS
  • declares the current x402 version (2)
  • EIP-712 domain parameters present on every EVM entry
  • x402 v2 envelope delivered in the payment-required header

SITE PILLARS

  • homepage reachable
  • openapi doc
  • pricing page
  • llms.txt
  • robots.txt
  • terms page
recent checks (18) live · click to expand
TIME STATUS RESP CAUSE
● OK 826ms
● OK 619ms
● OK 961ms
● OK 1043ms
● OK 1156ms
● OK 1270ms
● SLOW 2118ms
● SLOW 1848ms
● OK 674ms
● OK 1106ms
● OK 495ms
● SLOW 1737ms
● OK 534ms
● OK 316ms
● OK 720ms
● OK 624ms
● OK 537ms
● OK 637ms

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