feat: complete typed Account Data API

AGENTS.md

@@ -11,7 +11,7 @@ mvn -pl library package    # build only the library module
 mvn -pl examples package   # build only the examples module
 ```
 
-There are no tests in this project. CI runs `mvn clean package` on PRs targeting `master`.
+The library's JUnit 5 tests use JSON fixtures and Mockito mocks of `KrakenRestRequester`, without network access or API keys. Run them with `mvn -pl library test`. CI runs `mvn clean package` on PRs targeting `master`.
 
 Java 25 with Temurin is required (configured via `maven-compiler-plugin` with `<release>25</release>`).
 

README.md

@@ -103,6 +103,26 @@ JsonNode order = api.query(KrakenAPI.Private.ADD_ORDER, Map.of(
 // Exception in thread "main" KrakenException(errors=[EGeneral:Permission denied])
 ```
 
+### Account data
+
+All Account Data operations have typed methods, including balances, credit lines, orders, amendments, trades, positions, fee tiers, API key information, wallets, ledgers, and report exports. Optional settings use the corresponding `...Params.builder()`; omitted values keep Kraken's defaults.
+
+```java
+Map<String, BigDecimal> balances = api.accountBalance();
+OpenOrders orders = api.openOrders(OpenOrdersParams.builder().trades(true).build());
+ClosedOrders page = api.closedOrders(ClosedOrdersParams.builder().offset(50).withoutCount(true).build());
+Map<String, AccountTrade> trades = api.queryTrades(QueryTradesParams.builder().transactionIds(List.of("THVRQM-33VKH-UCI7BS")).build());
+TradeVolume fees = api.tradeVolume(TradeVolumeParams.builder()
+        .pairsWithClass(List.of(new TradeVolumeParams.Pair("TSLAx/USD", "equity_pair")))
+        .feeSchedule(true).build());
+```
+
+`closedOrders` and `tradesHistory` expose the returned count, which is null when omitted by Kraken. Their `start` and `end` filters accept timestamp strings or transaction IDs. Monetary values use `BigDecimal`, timestamps use `Instant`, including fractional trade times and amendment times decoded from epoch nanoseconds. `creditLines` returns `Optional.empty()` when Kraken reports no credit lines. `accountBalance` can select a wallet using `AccountBalanceParams.accountId`, while `walletAccounts` lists the available wallets.
+
+`TradeVolumeParams` encodes requests as JSON to support class-qualified pairs. Custom REST requesters should send `endpoint.encodedParamsWith(nonce)` unchanged with `endpoint.getContentType()` and use `endpoint.unwrapResponse(response)` to handle endpoint-specific nullable results.
+
+Custom `KrakenNonceGenerator` implementations must produce increasing unsigned 64-bit integers as canonical decimal strings. `TradeVolume` encodes the nonce as a JSON number and rejects malformed, out-of-range or noncanonical values with an `IllegalStateException` that names the generator contract. Canonical formatting keeps the nonce used for signing identical to the number in the JSON body.
+
 ### Custom endpoints
 
 An endpoint the library doesn't implement can also be given a proper type, instead of falling back to `JsonNode`. Extend `PublicEndpoint<T>`, or `PrivateEndpoint<T>` for a private one, and pass your endpoint to `query`:

library/pom.xml

@@ -12,4 +12,22 @@
     <artifactId>kraken-api</artifactId>
     <name>Java Kraken API Client</name>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
 </project>