Remove subgraph links, add kong and ydaemon docs

docs/contributing/contribute.md

@@ -92,14 +92,12 @@ This is complementary to the above, but it's not directly related to creating st
 - [Yearn Governance Forum](https://gov.yearn.fi/)
 - [Yearn Snapshot Governance Voting](https://snapshot.box/#/s:veyfi.eth)
 
-#### List of Yearn Tools
+#### List of Yearn Data Tools
 
-- Yearn Subgraphs, [Ethereum](https://thegraph.com/explorer/subgraph?id=0xf50b705e4eaba269dfe954f10c65bd34e6351e0c-0&version=0xf50b705e4eaba269dfe954f10c65bd34e6351e0c-0-0&view=Overview), [Fantom](https://thegraph.com/hosted-service/subgraph/yearn/yearn-vaults-v2-fantom), [GitHub](https://github.com/yearn/yearn-vaults-v2-subgraph)
-- Yearn SDK, [GitHub](https://github.com/yearn/yearn-sdk)
-- Yearn API, [GitHub](https://github.com/yearn/kong)
-- Yearn Discord FAQ Bot, [GitHub](https://github.com/danijelthales/yfi-faq-bot)
+- yDaemon API, [GitHub](https://github.com/yearn/ydaemon)
+- Kong API, [GitHub](https://github.com/yearn/kong)
 
-### Legacy Products and Websites
+### Old Legacy Products and Websites
 
 - Former list of [open GitHub issues here](https://contribute.yearn.rocks/).
 - [v1 yearn.fi](https://v1.yearn.fi), [GitHub](https://github.com/yearn/iearn-finance)

docs/developers/building-on-yearn.md

@@ -37,21 +37,19 @@ V2 and V3 vaults implement strategies differently, so it is important to get fam
 
 ### Frontend Integrations
 
-Yearn uses a JavaScript SDK for formatting protocol data and generating transactions for reading/writing protocol data. Yearn SDK integrates several components, both on-chain and off-chain.
-
-[The repository here](https://github.com/turtlemoji/yearn-sdk-examples) contains a live preview and example usage of the Yearn SDK. Explore this codebase to learn how to start interacting with the Yearn protocol in your own app.
+Yearn uses Kong and yDaemon as frontend data sources. Old Yearn SDKs existed, but as of late 2025, only yDaemon and Kong are actively used.
 
 Check out the [Frontend Integrations](front-end-development) section of this documentation for more information about Frontend Integrations.
 
 ### Data Sources
 
-[**yDaemon**](https://ydaemon.yearn.fi/) is a public API for a broad range of Vault data.
+[**Kong**](https://kong.yearn.fi/api/gql) is an API to submit graphql queries for Yearn data.
 
-- Learn more about yDaemon in the [README](https://github.com/yearn/ydaemon)
+- Learn more about kong [here](/developers/data-services/kong) and in the [README](https://github.com/yearn/kong).
 
-**The Graph** - Query contract data with GQL using the Yearn subgraphs
+[**yDaemon**](https://ydaemon.yearn.fi/) is a public API for a broad range of Vault data.
 
-- Learn more about the Graph and Subgraphs that Yearn provides [here](./data-services/subgraph-info).
+- Learn more about yDaemon [here](/developers/data-services/ydaemon) and in the [README](https://github.com/yearn/ydaemon)
 
 ## Data Analysis
 

docs/developers/data-services/kong.md

@@ -0,0 +1,125 @@
+# Kong
+
+[Kong](https://github.com/yearn/kong) is a real-time/historical EVM indexer and analytics platform designed to make it easy to index EVM logs, enrich blockchain data, and query indexed data via GraphQL. It comes pre-configured with an index over Yearn's v2 and v3 vault ecosystems. For more detailed docs, reference [deepwiki](https://deepwiki.com/yearn/kong).
+
+## Key Features
+
+### Event Sourcing Architecture
+
+- Stores EVM logs and contract snapshots in PostgreSQL without transformation
+- Supports index replay without re-extracting data from blockchain
+- Handles events out of order for faster historical indexing
+
+### Hook System
+
+Three types of custom enrichment hooks:
+- **Snapshot Hooks**: Process recurring snapshots of contracts
+- **Event Hooks**: Process and enrich blockchain events
+- **Timeseries Hooks**: Generate time-series analytics data
+
+### Real-Time Webhooks
+
+- Real-time notifications triggered during indexing
+- HMAC-SHA256 authentication
+- Configurable filtering by chains and contract addresses
+
+### Domain Modeling with "Things"
+
+- Dynamically created entities (analogous to "entities" in conventional ETL)
+- Used as sources for further indexing
+- Supports hierarchical indexing (e.g., Registry → Vaults → Strategies)
+
+## GraphQL API
+
+### Base URL
+
+- GraphQL Explorer: https://kong.yearn.fi/api/gql
+
+### Example Queries
+
+#### List Yearn Vaults on mainnet
+
+```graphql
+query MainnetVaults {
+  vaults(chainId: 1) {
+    address
+    name
+    symbol
+  }
+}
+```
+
+#### List Yearn v2 vaults on all chains
+
+```graphql
+query GetV2VaultAddresses {
+  vaults(vaultType: 2) {
+    chainId
+    address
+    name
+    symbol
+  }
+}
+```
+
+### Query last 100 deposit events for specific vault
+
+```graphql
+query GetDeposits {
+  deposits(chainId: 1, address: "0xBe53A109B494E5c9f97b9Cd39Fe969BE68BF6204") {
+    amount
+    shares
+    recipient
+  }
+}
+```
+
+#### Query Timeseries Data for specific vault
+
+```graphql
+query Timeseries {
+  timeseries(
+    label: "tvl-c",
+    component: "tvl",
+    chainId: 1,
+    address: "0xdA816459F1AB5631232FE5e97a05BBBb94970c95",
+    limit: 1000
+  ) {
+    chainId
+    address
+    label
+    component
+    value
+    time
+    period
+  }
+}
+```
+
+## Database Schema
+
+### Core Tables
+
+#### `thing`
+Domain object definitions (vaults, strategies, etc.)
+- `chain_id`, `address`, `label`, `defaults` (JSONB)
+
+#### `snapshot`
+Latest contract snapshots with hook data
+- Stores contract state and enriched hook data
+- JSONB fields for flexible schema
+
+#### `evmlog`
+Raw EVM logs with hook enrichments
+- Full event history with args and hook data in JSONB
+- Limited history on transfers, deposits, withdraws, approves
+
+#### `evmlog_strides`
+Track which blocks have been indexed
+- Prevents duplicate indexing
+- Identifies gaps in coverage
+
+#### `output`
+Timeseries data from timeseries hooks
+- TVL, APY, PPS calculations
+- Time-series analytics