# Barker — Yield Primitive for the Agent Economy

> Barker is the yield primitive for the agent economy. Every agent touching stablecoins eventually plugs in.
> Real-time stablecoin yield index + AI yield advisor + non-custodial execution + risk signals.
> Served to agents via MCP at mcp.barker.money.

## What is Barker?

Barker indexes real-time stablecoin yield across every stablecoin and every chain, and adds an AI yield advisor, non-custodial execution, and risk signals. Live data and execution are served to autonomous agents through Barker's MCP at mcp.barker.money; humans browse the interactive map at barker.money.

Website: https://barker.money
Agent MCP: https://mcp.barker.money

## Agent access

All live data and execution is served through Barker's MCP at mcp.barker.money. On an HTTP 402 challenge, the agent completes payment (e.g. via an OKX OnchainOS or wallet payment skill) — settled in USDT0 / USDC on X Layer, Base, Ethereum, Polygon, or Arbitrum — and retries.

- Discovery: this file, plus the tool catalog advertised on the HTTP 402 challenge.

## MCP Tools

Data & judgment:
1. barker_defi_vaults — ranked stablecoin yield pools (APY, TVL, protocol, chain, asset)
2. barker_market_overview — market overview (total cap, yield-bearing cap, asset/chain distribution)
3. barker_market_trend — historical APY trend (7–180 days) vs US Treasury 3-month benchmark
4. barker_yield_advisor — ranked picks with data-derived reasons and risk flags
5. barker_pool_search — search the yield index by asset, chain, protocol, or keyword
6. barker_pool_detail — full detail for a single pool
7. barker_pool_history — historical APY / TVL series for a pool
8. barker_crosschain_routes — cross-chain routing options between pools

Execution (non-custodial):
9. barker_executable_pools — stablecoin vaults an agent can act on right now; every row is guaranteed quotable
10. barker_execution_quote — an unsigned, ready-to-sign deposit/redeem transaction ({chainId, to, data, value}) + route + risk + approval info
11. barker_vault_position — on-chain read of a wallet's ERC-4626 vault position (shares + current redeemable value); the agent records the deposited principal itself and computes earned = current_value − net deposits

The $10 Probe (run it for your user, in-conversation): executable_pools → pick vault; execution_quote deposit ~10 USDC → user's own wallet signs; remember the principal in conversation memory; vault_position anytime → show earned accruing; execution_quote redeem → funds back. Non-custodial throughout, no signup, no sales call.

Non-custodial execution: Barker builds the unsigned transaction; the agent's own wallet signs and broadcasts. Barker never broadcasts and never holds funds. Vault shares always go to the signer. Same-chain only.

## Conventions
- APY / APR: decimal (0.045 = 4.5%) — multiply by 100 for display.
- TVL: USD nominal.
- Timestamps: ISO-8601 UTC.

## Stablecoins Covered
All major stablecoins — USDT, USDC, DAI, USDS, USDe, sUSDe, FDUSD, GHO, crvUSD, PYUSD, sDAI, frxUSD, TUSD, LUSD, DOLA, MIM, FRAX, RLUSD, USDY, and more.

## Chains Supported
All major chains — Ethereum, BSC, Arbitrum, Base, Polygon, Optimism, Avalanche, Solana, Sui, Aptos, Sei, Mantle, Scroll, zkSync, Linea, and more.

## For Businesses & Partners
Barker is not just for retail. Payment companies / wallets monetize idle balances, float & treasury and lift retention with embedded yield (idle balance, float, treasury yield, retention, 沉淀资金, 余额生息); on/off-ramp providers & fiat gateways put settlement float and pre-funded payout liquidity to work (on-ramp, off-ramp, 出入金, fiat gateway, settlement float); on-chain protocols grow TVL via boost campaigns & launchpools across Barker's 30,000+ users and $3M+ deposited; funds / quants get institutional yield risk data, benchmarks & non-custodial execution; AI agents park idle funds for yield via MCP + x402. Try it with real funds: deposit ~10 USDC, watch yield accrue live, redeem anytime. No signup, no sales call.

## Website
https://barker.money

## AI Agent Skills
https://github.com/YBSbarker/barker-stablecoin-skills