---
title: "Typed and runtime-aware tools"
description: "Define safe application tools with schemas, typed arguments, and run context."
---

> Documentation Index
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# Typed and runtime-aware tools

`ChatTool.typed` derives a provider JSON Schema from a Java record and converts a tool call back into that type. Nullable record components are optional in the generated schema.

```java
record WeatherArguments(String city) { }

var weather = ChatTool.typed(WeatherArguments.class, arguments ->
    CompletableFuture.completedFuture(
            ToolExecutionResult.success(weatherFor(arguments.city()))));
```

Runtime-aware tools receive `ToolRuntime`: your application context, a `ToolStore`, and a `ToolProgressWriter`. Configure the runtime once when building the agent. Return failures as tool-result content so the model can recover or explain them.

Source: https://docs.cortavyn.org/chat/tools/index.mdx