Crate agentkit_tools_core 

Core abstractions for defining, registering, executing, and governing tools in agentkit.

This crate provides the Tool trait, ToolRegistry, BasicToolExecutor, and a layered permission system built on PermissionChecker, PermissionPolicy, and CompositePermissionChecker. Together these types let you:

• Define tools by implementing Tool with a ToolSpec and async invoke method.
• Register tools in a ToolRegistry and hand it to an executor or capability provider.
• Check permissions before execution using composable policies (PathPolicy, CommandPolicy, McpServerPolicy, CustomKindPolicy).
• Handle interruptions (approval prompts, OAuth flows) via the ToolInterruption / ApprovalRequest / AuthRequest types.
• Bridge to the capability layer with ToolCapabilityProvider, which wraps every registered tool as an Invocable.

Structs

ApprovalRequest

A request sent to the host when a tool execution needs human approval.

AuthRequest

A request for authentication credentials before a tool can proceed.

BasicToolExecutor

The default ToolExecutor that looks up tools in a ToolRegistry, checks permissions via Tool::proposed_requests, and invokes the tool.

CommandPolicy

A PermissionPolicy that governs ShellPermissionRequests by checking the executable name, working directory, and environment variables.

CompositePermissionChecker

Chains multiple PermissionPolicy implementations into a single PermissionChecker.

CustomKindPolicy

A PermissionPolicy that matches requests whose PermissionRequest::kind starts with "custom." and allows or denies them by name.

McpServerPolicy

A PermissionPolicy that governs McpPermissionRequests by checking whether the target server is trusted and the requested auth scopes are in the allow-list.

OwnedToolContext

Owned execution context that can outlive a single stack frame.

PathPolicy

A PermissionPolicy that governs FileSystemPermissionRequests by checking whether target paths fall within allowed or protected directory trees.

PermissionDenial

Structured denial produced when a PermissionChecker rejects an operation.

ShellPermissionRequest

Permission request for executing a shell command.

ToolAnnotations

Hints that describe behavioural properties of a tool.

ToolCapabilityProvider

A CapabilityProvider that exposes every tool in a ToolRegistry as an Invocable in the agentkit capability layer.

ToolContext

Runtime context passed to every Tool::invoke call.

ToolInvocableAdapter

Wraps a Tool as an Invocable so it can be surfaced through the agentkit capability layer.

ToolName

Unique name identifying a Tool within a ToolRegistry.

ToolRegistry

A name-keyed collection of Tool implementations.

ToolRequest

An incoming request to execute a tool.

ToolResult

The output produced by a successful tool invocation.

ToolSpec

Declarative specification of a tool’s identity, schema, and behavioural hints.

Enums

ApprovalDecision

The user’s response to an ApprovalRequest.

ApprovalReason

Why a permission policy is requesting human approval before proceeding.

AuthOperation

Describes the operation that triggered an AuthRequest.

AuthResolution

The outcome of an AuthRequest after the user interacts with the auth flow.

FileSystemPermissionRequest

Permission request for a filesystem operation.

McpPermissionRequest

Permission request for an MCP (Model Context Protocol) operation.

PermissionCode

Machine-readable code indicating why a permission was denied.

PermissionDecision

The verdict from a PermissionChecker for a single PermissionRequest.

PolicyMatch

The result of a single PermissionPolicy evaluation.

ToolError

Errors that can occur during tool lookup, permission checking, or execution.

ToolExecutionOutcome

The three-way result of a ToolExecutor::execute call.

ToolInterruption

A tool execution was paused because it needs external input.

Traits

PermissionChecker

Evaluates a PermissionRequest and returns a final PermissionDecision.

PermissionPolicy

A single, focused permission rule that contributes to a composite decision.

PermissionRequest

A description of an operation that requires permission before it can proceed.

Tool

The central abstraction for an executable tool in an agentkit agent.

ToolExecutor

Trait for executing tool calls with permission checking and interruption handling.

ToolResources

Trait for dependency injection into tool implementations.