Shared from "Claude-Code" on Inkdown
The complete
Tooltype system — every method, every hook, every rendering path.
Tool.ts (792 lines) defines the complete interface that every tool must implement. This is one of the most important type definitions in the codebase.
interface Tool<Input = unknown, Output = unknown, P = unknown> {
// ─── Identity ───────────────────────────────────────────
name: string // Unique identifier (e.g., "Bash")
description: string // Shown to model in system prompt
// ─── Schema ─────────────────────────────────────────────
parameters: JSONSchema7 // JSON Schema for input validation
optionsSchema?: JSONSchema7 // Optional options schema
// ─── Runtime Checks ─────────────────────────────────────
isEnabled(): boolean // Is this tool available right now?
isAutoApproved(context): boolean // Skip permission prompt?
// ─── Execution ──────────────────────────────────────────
call(input, context): AsyncIterable<ToolResult<Output>>
// ─── Input Validation ───────────────────────────────────
validateInput?(input): ValidationResult
// ─── Rendering (UI display) ─────────────────────────────
renderToolUseMessage(block, context): ReactNode
renderToolResultMessage(result, context): ReactNode
renderToolUseProgressMessage(progress, context): ReactNode
renderToolUseErrorMessage(error, context): ReactNode
renderToolUseRejectedMessage(context): ReactNode
renderGroupedToolUse?(blocks, context): ReactNode
// ─── Activity Description (status bar) ──────────────────
getActivityDescription?(input): string
// ─── Auto-Classifier ────────────────────────────────────
toAutoClassifierInput?(input): AutoClassifierInput
// ─── Tool Classification ────────────────────────────────
isSearchOrReadCommand(): boolean
isConcurrencySafe(): boolean
isReadOnly(): boolean
isDestructive(): boolean
// ─── Interrupt Behavior ─────────────────────────────────
interruptBehavior: InterruptBehavior
// ─── Deferral ───────────────────────────────────────────
shouldDefer?(input, context): boolean
// ─── Always Load ────────────────────────────────────────
alwaysLoad: boolean // Always include in system prompt
// ─── Observable Input Backfill ──────────────────────────
backfillObservableInput?(input): void
// ─── MCP Info ───────────────────────────────────────────
mcpInfo?: { serverName: string; toolName: string }
}What a tool returns from call():
type ToolResult<T> = {
content: ToolResultContent[] // The result content
newMessages?: Message[] // Optional messages to inject
contextModifier?: (ctx) => ctx // Optional context modification
}The massive context object passed to every tool call:
interface ToolUseContext {
// Abort control
abortController: AbortController
// App state access
getAppState(): AppState
setAppState(updater): void
// Query tracking
queryTracking: { chainId: string; depth: number }
// Tool pool
options: {
tools: Tool[]
mainLoopModel: string
thinkingConfig: ThinkingConfig
agentDefinitions: AgentDefinitions
isNonInteractiveSession: boolean
appendSystemPrompt?: string
}
// Agent identity
agentId?: string
// Notification system
addNotification(notification): void
// File state cache
fileStateCache: FileStateCache
// Content replacement state
contentReplacementState?: ContentReplacementState
// Messages (current conversation)
messages: Message[]
}Immutable permission rules:
interface ToolPermissionContext {
mode: PermissionMode // 'default' | 'yolo' | 'plan' | 'bypassPermissions'
// Rule sources (for debugging/display)
alwaysAllow: Rule[] // Auto-approved patterns
alwaysDeny: Rule[] // Auto-denied patterns
alwaysAsk: Rule[] // Always prompt user
}How a tool behaves when the user interrupts:
enum InterruptBehavior {
KILL = 'kill', // Kill the process immediately
WAIT = 'wait', // Let it finish gracefully
IGNORE = 'ignore', // Continue running in background
}Creates a tool with safe defaults:
function buildTool<Input, Output, P>(
partial: PartialTool<Input, Output, P>
): Tool<Input, Output, P> {
return {
alwaysLoad: false,
interruptBehavior: InterruptBehavior.KILL,
isEnabled: () => true,
isAutoApproved: () => false,
isSearchOrReadCommand: () => false,
isConcurrencySafe: () => false,
isReadOnly: () => false,
isDestructive: () => false,
shouldDefer: () => false,
validateInput: () => ({ valid: true }),
...partial,
}
}Re-exported progress types for UI rendering:
// Progress types for each tool
AgentToolProgress
BashProgress
MCPProgress
TaskProgress
TeamProgress
ComputerUseProgress
WebBrowserProgress
// ... etcCalled when the model calls the tool. Returns the UI to display:
┌──────────────────────────────────────┐
│ $ npm test │
│ Running tests... │
└──────────────────────────────────────┘Called when the tool completes. Returns the result UI:
┌──────────────────────────────────────┐
│ ✓ 42 tests passed (3.2s) │
└──────────────────────────────────────┘Called during streaming progress:
┌──────────────────────────────────────┐
│ Running tests... 23/42 passed │
│ ████████████░░░░░░░░ 55% │
└──────────────────────────────────────┘Returns the one-liner shown in the status bar:
getActivityDescription({ command: "npm test" })
// → "Running tests"| File | Purpose |
|---|---|
src/Tool.ts | Complete tool interface (792 lines) |
src/tools.ts | Tool assembly and merging |
src/tools/shared/ | Shared tool utilities |
src/tools/utils.ts | Tool utility functions |
src/utils/permissions/ | Permission system |
src/services/tools/ | Tool orchestration |