feat(coding-agent): type ToolCallEvent.input per tool

Matches ToolResultEvent pattern with typed inputs via discriminated union.

- Export *ToolInput types from tool schemas
- Add *ToolCallEvent interfaces for each built-in tool
- Add isToolCallEventType() guard with overloads for built-ins

Direct narrowing (event.toolName === "bash") doesn't work due to
CustomToolCallEvent.toolName: string overlapping with literals.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/coding-agent/src/core/tools/bash.ts

@@ -3,7 +3,7 @@ import { createWriteStream, existsSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import type { AgentTool } from "@mariozechner/pi-agent-core";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { spawn } from "child_process";
 import { getShellConfig, getShellEnv, killProcessTree } from "../../utils/shell.js";
 import { DEFAULT_MAX_BYTES, DEFAULT_MAX_LINES, formatSize, type TruncationResult, truncateTail } from "./truncate.js";
@@ -21,6 +21,8 @@ const bashSchema = Type.Object({
 	timeout: Type.Optional(Type.Number({ description: "Timeout in seconds (optional, no default timeout)" })),
 });
 
+export type BashToolInput = Static<typeof bashSchema>;
+
 export interface BashToolDetails {
 	truncation?: TruncationResult;
 	fullOutputPath?: string;

packages/coding-agent/src/core/tools/edit.ts

@@ -1,5 +1,5 @@
 import type { AgentTool } from "@mariozechner/pi-agent-core";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { constants } from "fs";
 import { access as fsAccess, readFile as fsReadFile, writeFile as fsWriteFile } from "fs/promises";
 import {
@@ -19,6 +19,8 @@ const editSchema = Type.Object({
 	newText: Type.String({ description: "New text to replace the old text with" }),
 });
 
+export type EditToolInput = Static<typeof editSchema>;
+
 export interface EditToolDetails {
 	/** Unified diff of the changes made */
 	diff: string;

packages/coding-agent/src/core/tools/find.ts

@@ -1,5 +1,5 @@
 import type { AgentTool } from "@mariozechner/pi-agent-core";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { spawnSync } from "child_process";
 import { existsSync } from "fs";
 import { globSync } from "glob";
@@ -16,6 +16,8 @@ const findSchema = Type.Object({
 	limit: Type.Optional(Type.Number({ description: "Maximum number of results (default: 1000)" })),
 });
 
+export type FindToolInput = Static<typeof findSchema>;
+
 const DEFAULT_LIMIT = 1000;
 
 export interface FindToolDetails {

packages/coding-agent/src/core/tools/grep.ts

@@ -1,6 +1,6 @@
 import { createInterface } from "node:readline";
 import type { AgentTool } from "@mariozechner/pi-agent-core";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { spawn } from "child_process";
 import { readFileSync, statSync } from "fs";
 import path from "path";
@@ -29,6 +29,8 @@ const grepSchema = Type.Object({
 	limit: Type.Optional(Type.Number({ description: "Maximum number of matches to return (default: 100)" })),
 });
 
+export type GrepToolInput = Static<typeof grepSchema>;
+
 const DEFAULT_LIMIT = 100;
 
 export interface GrepToolDetails {

packages/coding-agent/src/core/tools/index.ts

@@ -1,18 +1,48 @@
 export {
 	type BashOperations,
 	type BashToolDetails,
+	type BashToolInput,
 	type BashToolOptions,
 	bashTool,
 	createBashTool,
 } from "./bash.js";
-export { createEditTool, type EditOperations, type EditToolDetails, type EditToolOptions, editTool } from "./edit.js";
-export { createFindTool, type FindOperations, type FindToolDetails, type FindToolOptions, findTool } from "./find.js";
-export { createGrepTool, type GrepOperations, type GrepToolDetails, type GrepToolOptions, grepTool } from "./grep.js";
-export { createLsTool, type LsOperations, type LsToolDetails, type LsToolOptions, lsTool } from "./ls.js";
+export {
+	createEditTool,
+	type EditOperations,
+	type EditToolDetails,
+	type EditToolInput,
+	type EditToolOptions,
+	editTool,
+} from "./edit.js";
+export {
+	createFindTool,
+	type FindOperations,
+	type FindToolDetails,
+	type FindToolInput,
+	type FindToolOptions,
+	findTool,
+} from "./find.js";
+export {
+	createGrepTool,
+	type GrepOperations,
+	type GrepToolDetails,
+	type GrepToolInput,
+	type GrepToolOptions,
+	grepTool,
+} from "./grep.js";
+export {
+	createLsTool,
+	type LsOperations,
+	type LsToolDetails,
+	type LsToolInput,
+	type LsToolOptions,
+	lsTool,
+} from "./ls.js";
 export {
 	createReadTool,
 	type ReadOperations,
 	type ReadToolDetails,
+	type ReadToolInput,
 	type ReadToolOptions,
 	readTool,
 } from "./read.js";
@@ -26,7 +56,13 @@ export {
 	truncateLine,
 	truncateTail,
 } from "./truncate.js";
-export { createWriteTool, type WriteOperations, type WriteToolOptions, writeTool } from "./write.js";
+export {
+	createWriteTool,
+	type WriteOperations,
+	type WriteToolInput,
+	type WriteToolOptions,
+	writeTool,
+} from "./write.js";
 
 import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { type BashToolOptions, bashTool, createBashTool } from "./bash.js";

packages/coding-agent/src/core/tools/ls.ts

@@ -1,5 +1,5 @@
 import type { AgentTool } from "@mariozechner/pi-agent-core";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { existsSync, readdirSync, statSync } from "fs";
 import nodePath from "path";
 import { resolveToCwd } from "./path-utils.js";
@@ -10,6 +10,8 @@ const lsSchema = Type.Object({
 	limit: Type.Optional(Type.Number({ description: "Maximum number of entries to return (default: 500)" })),
 });
 
+export type LsToolInput = Static<typeof lsSchema>;
+
 const DEFAULT_LIMIT = 500;
 
 export interface LsToolDetails {

packages/coding-agent/src/core/tools/read.ts

@@ -1,6 +1,6 @@
 import type { AgentTool } from "@mariozechner/pi-agent-core";
 import type { ImageContent, TextContent } from "@mariozechner/pi-ai";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { constants } from "fs";
 import { access as fsAccess, readFile as fsReadFile } from "fs/promises";
 import { formatDimensionNote, resizeImage } from "../../utils/image-resize.js";
@@ -14,6 +14,8 @@ const readSchema = Type.Object({
 	limit: Type.Optional(Type.Number({ description: "Maximum number of lines to read" })),
 });
 
+export type ReadToolInput = Static<typeof readSchema>;
+
 export interface ReadToolDetails {
 	truncation?: TruncationResult;
 }

packages/coding-agent/src/core/tools/write.ts

@@ -1,5 +1,5 @@
 import type { AgentTool } from "@mariozechner/pi-agent-core";
-import { Type } from "@sinclair/typebox";
+import { type Static, Type } from "@sinclair/typebox";
 import { mkdir as fsMkdir, writeFile as fsWriteFile } from "fs/promises";
 import { dirname } from "path";
 import { resolveToCwd } from "./path-utils.js";
@@ -9,6 +9,8 @@ const writeSchema = Type.Object({
 	content: Type.String({ description: "Content to write to the file" }),
 });
 
+export type WriteToolInput = Static<typeof writeSchema>;
+
 /**
  * Pluggable operations for the write tool.
  * Override these to delegate file writing to remote systems (e.g., SSH).