FunctionToolStore

This docs was updated at: 2026-02-23

com.paragon.responses.spec.FunctionToolStore  ·  Class

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A store that maps function names to their implementations.

This store enables calling function tools directly from API responses by binding the function name and JSON arguments from the response to the actual function implementation.

Example usage:

// Create and add tools
var getWeatherTool = new GetWeatherTool();
var store = FunctionToolStore.create()
    .add(getWeatherTool);
// Make API call
var response = responder.respond(payload).join();
// Get callable function tool calls
var functionToolCalls = response.functionToolCalls(store);
FunctionToolCallOutput result = functionToolCalls.getFirst().call();

Methods

create

public static @NonNull FunctionToolStore create()

Creates a new FunctionToolStore with a default ObjectMapper.

Returns

a new empty store

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create

public static @NonNull FunctionToolStore create(@NonNull ObjectMapper objectMapper)

Creates a new FunctionToolStore with the specified ObjectMapper.

Parameters

Name	Description
objectMapper	the ObjectMapper to use for deserializing function arguments

Returns

a new empty store

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add

public @NonNull FunctionToolStore add(@NonNull FunctionTool<?> tool)

Adds a function tool to this store. The tool will be stored under its name as returned by FunctionTool.getName().

Parameters

Name	Description
tool	the function tool to add

Returns

this store for method chaining

Throws

Type	Condition
IllegalArgumentException	if a tool with the same name is already stored

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addAll

public @NonNull FunctionToolStore addAll(@NonNull FunctionTool<?>... tools)

Adds multiple function tools to this store.

Parameters

Name	Description
tools	the function tools to add

Returns

this store for method chaining

Throws

Type	Condition
IllegalArgumentException	if any tool has a duplicate name

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addAll

public @NonNull FunctionToolStore addAll(@NonNull Iterable<? extends FunctionTool<?>> tools)

Adds multiple function tools to this store.

Parameters

Name	Description
tools	the function tools to add

Returns

this store for method chaining

Throws

Type	Condition
IllegalArgumentException	if any tool has a duplicate name

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bind

public @NonNull BoundedFunctionCall bind(@NonNull FunctionToolCall toolCall)

Binds a function tool call from the API response to its implementation.

This creates a BoundedFunctionCall that can be invoked via BoundedFunctionCall.call().

Parameters

Name	Description
toolCall	the function tool call from the API response

Returns

a bounded function call that can be invoked

Throws

Type	Condition
IllegalArgumentException	if no tool is stored for the function name

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bindAll

public @NonNull List<BoundedFunctionCall> bindAll(@NonNull List<FunctionToolCall> toolCalls)

Binds all function tool calls from the API response to their implementations.

Parameters

Name	Description
toolCalls	the function tool calls from the API response

Returns

a list of bounded function calls that can be invoked

Throws

Type	Condition
IllegalArgumentException	if any tool call references a function not in the store

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contains

public boolean contains(@NonNull String name)

Checks if a tool with the given name is stored.

Parameters

Name	Description
name	the function name to check

Returns

true if a tool with this name is stored

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get

public FunctionTool<?> get(@NonNull String name)

Gets a tool by name.

Parameters

Name	Description
name	the function name

Returns

the tool, or null if not found

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getObjectMapper

public @NonNull ObjectMapper getObjectMapper()

Returns the ObjectMapper used by this store.

Returns

the ObjectMapper

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execute

public @NonNull FunctionToolCallOutput execute(@NonNull FunctionToolCall toolCall)
      throws JsonProcessingException

Executes a function tool call and returns the result.

This is a convenience method that binds and calls in one step.

Parameters

Name	Description
toolCall	the function tool call to execute

Returns

the function tool call output

Throws

Type	Condition
JsonProcessingException	if the arguments cannot be deserialized
IllegalArgumentException	if no tool is stored for the function name

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executeAll

public @NonNull List<FunctionToolCallOutput> executeAll(@NonNull List<FunctionToolCall> toolCalls)
      throws JsonProcessingException

Executes all function tool calls and returns their results.

Parameters

Name	Description
toolCalls	the function tool calls to execute

Returns

a list of function tool call outputs

Throws

Type	Condition
JsonProcessingException	if any arguments cannot be deserialized
IllegalArgumentException	if any tool call references a function not in the store