Roundhouse

Barker

The yield primitive for the agent economy — every agent touching stablecoins eventually plugs in. Live APY index across 500+ DeFi protocols and 20+ CEX. Free public data and agent-callable endpoints.

TradingLiveeip155:8453Exactvia cdp
https://mcp.barker.money/barker_defi_vaults
Calls · 30d
54↑ 49%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 30 snapshots so far.
$0.34
Verified settled volume
175 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0010
Listed price
As published in the catalog. Always read the live 402 before paying.
54
Calls · 30d
Upstream's own call count for this endpoint, not ours.
3
Unique payers · 30d
Last called 2026-09-23 08:00Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x83f15f5bea445109e255ab82622fbdfecd1e4c9f

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "error": "Payment required",
  "usage": {
    "hint": "Settle one of the `accepts` quotes, then retry this exact URL with the base64 payment payload in the PAYMENT-SIGNATURE header (x402 v2). Required query params are listed above; full JSON Schema is in extensions.bazaar.schema.",
    "method": "GET",
    "example": "https://mcp.barker.money/barker_defi_vaults?asset=usdc&chain=base&sort=apy&limit=10",
    "required": []
  },
  "accepts": [
    {
      "asset": "0x779ded0c9e1022225f8e0630b35a9b54be713736",
      "extra": {
        "name": "USD₮0",
        "version": "1"
      },
      "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
      "amount": "1000",
      "scheme": "exact",
      "network": "eip155:196",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "0x779ded0c9e1022225f8e0630b35a9b54be713736",
      "extra": {
        "name": "USD₮0",
        "version": "1"
      },
      "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
      "amount": "1000",
      "scheme": "aggr_deferred",
      "network": "eip155:196",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
      "amount": "1000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
      "amount": "1000",
      "scheme": "exact",
      "network": "eip155:1",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
      "amount": "1000",
      "scheme": "exact",
      "network": "eip155:137",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
      "amount": "1000",
      "scheme": "exact",
      "network": "eip155:42161",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://mcp.barker.money/barker_defi_vaults",
    "iconUrl": "https://barker.money/icons/icon-512x512.png",
    "mimeType": "application/json",
    "description": "Query real-time stablecoin supply yield pools from Barker's index of 500+ DeFi protocols. Returns ranked rows with protocol_name, chain_name, asset_symbol, supply_apy_total (decimal — multiply by 100 for %), and supply_tvl (USD). Use for questions like 'best stablecoin yield', 'where to earn on USDC', 'compare lending rates', '稳定币利率'.",
    "serviceName": "Barker"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "sort": "apy",
            "asset": "usdc",
            "chain": "base",
            "limit": 10
          }
        },
        "output": {
          "type": "json",
          "example": {
            "data": [
              {
                "pool_uid": "aave-v3_ethereum_usdc_supply",
                "chain_name": "ethereum",
                "supply_tvl": 1234567890,
                "asset_symbol": "USDC",
                "protocol_name": "Aave V3",
                "supply_apy_total": 0.0523
              }
            ],
            "success": true
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "properties": {
                  "sort": {
                    "enum": [
                      "apy",
                      "tvl"
                    ],
                    "type": "string",
                    "description": "Sort key"
                  },
                  "asset": {
                    "type": "string",
                    "description": "Stablecoin symbol (lowercase): usdt, usdc, dai, usde, usds, fdusd, gho, crvusd, pyusd, sdai, frxusd, tusd, lusd, dola, etc."
                  },
                  "chain": {
                    "type": "string",
                    "description": "Chain name (lowercase): ethereum, bsc, arbitrum, base, polygon, optimism, avalanche, solana, etc."
                  },
                  "limit": {
                    "type": "integer",
                    "maximum": 100,
                    "minimum": 1,
                    "description": "Row count (default 50, max 100)"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

1000units
on eip155:196 · exact scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to
0x83f1…e4c9f
Token contract
0x779d…13736
Payment window
5 minutes
1000units
on eip155:196 · aggr_deferred scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to
0x83f1…e4c9f
Token contract
0x779d…13736
Payment window
5 minutes
0.001USDC≈ $0.001 USD
on Base · exact scheme

Pay 0.001 USDC on Base to 0x83f1…e4c9f. The signed payment is good for 5 minutes.

Paid to
0x83f1…e4c9f
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
1000 smallest units
1000units
on Ethereum · exact scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to
0x83f1…e4c9f
Token contract
0xA0b8…6eB48
Payment window
10 minutes
1000units
on Polygon · exact scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to
0x83f1…e4c9f
Token contract
0x3c49…c3359
Payment window
10 minutes
1000units
on Arbitrum · exact scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to
0x83f1…e4c9f
Token contract
0xaf88…e5831
Payment window
10 minutes
The catalog’s raw entry
[
  {
    "asset": "0x779ded0c9e1022225f8e0630b35a9b54be713736",
    "extra": {
      "name": "USD₮0",
      "version": "1"
    },
    "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
    "amount": "1000",
    "scheme": "exact",
    "network": "eip155:196",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "0x779ded0c9e1022225f8e0630b35a9b54be713736",
    "extra": {
      "name": "USD₮0",
      "version": "1"
    },
    "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
    "amount": "1000",
    "scheme": "aggr_deferred",
    "network": "eip155:196",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
    "amount": "1000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
    "amount": "1000",
    "scheme": "exact",
    "network": "eip155:1",
    "maxTimeoutSeconds": 600
  },
  {
    "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
    "amount": "1000",
    "scheme": "exact",
    "network": "eip155:137",
    "maxTimeoutSeconds": 600
  },
  {
    "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x83f15f5bea445109e255ab82622fbdfecd1e4c9f",
    "amount": "1000",
    "scheme": "exact",
    "network": "eip155:42161",
    "maxTimeoutSeconds": 600
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "sort": "apy",
          "asset": "usdc",
          "chain": "base",
          "limit": 10
        }
      },
      "output": {
        "type": "json",
        "example": {
          "data": [
            {
              "pool_uid": "aave-v3_ethereum_usdc_supply",
              "chain_name": "ethereum",
              "supply_tvl": 1234567890,
              "asset_symbol": "USDC",
              "protocol_name": "Aave V3",
              "supply_apy_total": 0.0523
            }
          ],
          "success": true
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "properties": {
                "sort": {
                  "enum": [
                    "apy",
                    "tvl"
                  ],
                  "type": "string",
                  "description": "Sort key"
                },
                "asset": {
                  "type": "string",
                  "description": "Stablecoin symbol (lowercase): usdt, usdc, dai, usde, usds, fdusd, gho, crvusd, pyusd, sdai, frxusd, tusd, lusd, dola, etc."
                },
                "chain": {
                  "type": "string",
                  "description": "Chain name (lowercase): ethereum, bsc, arbitrum, base, polygon, optimism, avalanche, solana, etc."
                },
                "limit": {
                  "type": "integer",
                  "maximum": 100,
                  "minimum": 1,
                  "description": "Row count (default 50, max 100)"
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-09-24 08:00Z
Last indexed by Roundhouse
2026-09-24 09:20Z
Last enriched (probe, favicon, geo)
2026-09-11 14:46Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 402
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 30 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service Barker and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=Barker'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://mcp.barker.money/barker_defi_vaults, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402,
or use an organization key from https://roundhouseai.io/dashboard/team.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.