# Barker Yield Engine

> Yield-as-a-Service API & embed for wallets and payment apps.

- [Introduction](https://docs.barker.money/introduction.md): Welcome to Barker Yield Engine — embed institutional-grade stablecoin yield in your wallet or payment app.
- [Choosing an integration mode](https://docs.barker.money/integration-modes.md): Embed iframe vs Headless API — which one fits your product.
- [Quickstart](https://docs.barker.money/quickstart.md): Make your first Barker Yield Engine API call in 5 minutes.
- [Authentication](https://docs.barker.money/authentication.md): API key authentication and key management.
- [Rate Limits](https://docs.barker.money/rate-limits.md): Anti-abuse limits on the Partner API. There is no usage billing.
- [Embed (iframe)](https://docs.barker.money/embed.md): Drop a deposit/withdraw UI into your app with one line of HTML.
- [Headless API integration](https://docs.barker.money/integration-api.md): Build your own deposit/withdraw UI on top of the Barker REST API + BarkerEngine contract.
- [Multi-tier products](https://docs.barker.money/multi-tier-products.md): Offer 3 risk profiles (conservative / balanced / aggressive) by registering 3 product slugs.
- [Agent execution (x402)](https://docs.barker.money/agent-execution.md): Buy an unsigned, ready-to-sign vault transaction with a $0.05 micropayment — no account, no API key, non-custodial.
- [Webhooks](https://docs.barker.money/webhooks.md): Subscribe to product events and verify the HMAC-SHA256 signature.
- [Deposit / Redeem Lifecycle](https://docs.barker.money/deposit-redeem-lifecycle.md): Event sequence, confirmation depth, and how to reconcile your UI with on-chain state.
- [Smart Contracts](https://docs.barker.money/contracts-reference.md): BarkerEngine ABI for headless integrations. ERC-4626 standard.
- [Error Codes](https://docs.barker.money/error-codes.md): Error codes returned by the Barker Yield Engine API.
- [Failure Modes](https://docs.barker.money/failure-modes.md): How to handle RPC outages, tx replacement, chain reorgs, vault pauses, and webhook delivery failures.
- [Glossary](https://docs.barker.money/glossary.md): Terms used across the API, contracts, and portal.
- [SDKs](https://docs.barker.money/sdks.md): Official JavaScript and Python clients, plus how to generate your own from our OpenAPI spec.
- [API Changelog](https://docs.barker.money/api-changelog.md): Changes to Barker's data API and the x402 agent gateway. Additive-only: existing response fields never disappear, anchor field types never change.
- [Compliance & risk](https://docs.barker.money/compliance.md): Custody model, KYC responsibilities, risk disclosures, and what you must show to your users before deposit.
- [List all products for this partner](https://docs.barker.money/api-reference/products/list-all-products-for-this-partner.md): Returns every BarkerEngine product provisioned for the API key's partner — across all chains. Each entry includes the latest daily metrics snapshot (`latest_metrics`) when available; for products in `pending_deploy` status the metrics field is `null`.
- [Single product detail (with latest metrics)](https://docs.barker.money/api-reference/products/single-product-detail-with-latest-metrics.md): Same `Product` shape as the list endpoint, scoped to one slug. Use this when you already know the slug (e.g. from a deep-link or cached config) and don't need to fetch the whole list.
- [APY history (daily granularity)](https://docs.barker.money/api-reference/products/apy-history-daily-granularity.md): Time series of `underlying_apy` and `net_apy_for_user` for the product, one row per day. APY values are decimals (`0.0612` = 6.12%). Use this to render the APY chart on a partner dashboard.
- [Fee-split statistics over a date range](https://docs.barker.money/api-reference/products/fee-split-statistics-over-a-date-range.md): Daily breakdown of yield, partner fee earned, and Barker fee earned. Use this for partner accounting / reconciliation views. Range capped at 365 days; if `start_date` / `end_date` are omitted, defaults to the trailing 30 days.
- [Yield calculator (project annual / monthly yield for a principal)](https://docs.barker.money/api-reference/products/yield-calculator-project-annual-monthly-yield-for-a-principal.md): Stateless projection — give a principal amount, get back projected annual and monthly yield at the product's current `net_apy_for_user`. Good for "Earn $X/year" copy on a deposit form.
- [Engine + underlying vault health](https://docs.barker.money/api-reference/products/engine-+-underlying-vault-health.md): Operational status check. `is_paused` reflects the BarkerEngine pause state, and `underlying_ok` reflects whether the underlying ERC-4626 vault is operating normally (no upstream pause, accepting deposits).
- [Query a user's position in this product](https://docs.barker.money/api-reference/position/query-a-users-position-in-this-product.md): Returns the engine shares owned by `address`, converted to the underlying asset (`assets`) and to USD (`usd_value`). Use this to render "Your balance" in your UI.
- [Receive events pushed by partner (partner → Barker)](https://docs.barker.money/api-reference/webhooks/receive-events-pushed-by-partner-partner-→-barker.md): The partner POSTs events to Barker. - Must be HMAC-SHA256 signed (using the inbound secret configured in portal) - Must include the `Idempotency-Key` header — duplicates return 200 without re-processing

## OpenAPI Specs

- [openapi](/openapi.yaml)


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