refactor(read_file): Codex-inspired read_file refactor EXT-617 (#10981)

Author: hannesrudolph

apps/vscode-e2e/src/suite/tools/read-file.test.ts

@@ -376,7 +376,7 @@ suite.skip("Roo Code read_file Tool", function () {
 		}
 	})
 
-	test("Should read file with line range", async function () {
+	test("Should read file with slice offset/limit", async function () {
 		const api = globalThis.api
 		const messages: ClineMessage[] = []
 		let taskCompleted = false
@@ -446,7 +446,7 @@ suite.skip("Roo Code read_file Tool", function () {
 					alwaysAllowReadOnly: true,
 					alwaysAllowReadOnlyOutsideWorkspace: true,
 				},
-				text: `Use the read_file tool to read the file "${fileName}" and show me what's on lines 2, 3, and 4. The file contains lines like "Line 1", "Line 2", etc. Assume the file exists and you can read it directly.`,
+				text: `Use the read_file tool to read the file "${fileName}" using slice mode with offset=2 and limit=3 (1-based offset). The file contains lines like "Line 1", "Line 2", etc. After reading, show me the three lines you read.`,
 			})
 
 			// Wait for task completion
@@ -455,9 +455,8 @@ suite.skip("Roo Code read_file Tool", function () {
 			// Verify tool was executed
 			assert.ok(toolExecuted, "The read_file tool should have been executed")
 
-			// Verify the tool returned the correct lines (when line range is used)
+			// Verify the tool returned the correct lines (offset=2, limit=3 -> lines 2-4)
 			if (toolResult && (toolResult as string).includes(" | ")) {
-				// The result includes line numbers
 				assert.ok(
 					(toolResult as string).includes("2 | Line 2"),
 					"Tool result should include line 2 with line number",

packages/cloud/src/__tests__/CloudSettingsService.parsing.test.ts

@@ -81,7 +81,6 @@ describe("CloudSettingsService - Response Parsing", () => {
 				version: 2,
 				defaultSettings: {
 					maxOpenTabsContext: 10,
-					maxReadFileLine: 1000,
 				},
 				allowList: {
 					allowAll: false,

packages/types/src/cloud.ts

@@ -95,7 +95,6 @@ export const organizationDefaultSettingsSchema = globalSettingsSchema
 	.pick({
 		enableCheckpoints: true,
 		maxOpenTabsContext: true,
-		maxReadFileLine: true,
 		maxWorkspaceFiles: true,
 		showRooIgnoredFiles: true,
 		terminalCommandDelay: true,
@@ -107,7 +106,6 @@ export const organizationDefaultSettingsSchema = globalSettingsSchema
 	.merge(
 		z.object({
 			maxOpenTabsContext: z.number().int().nonnegative().optional(),
-			maxReadFileLine: z.number().int().gte(-1).optional(),
 			maxWorkspaceFiles: z.number().int().nonnegative().optional(),
 			terminalCommandDelay: z.number().int().nonnegative().optional(),
 			terminalShellIntegrationTimeout: z.number().int().nonnegative().optional(),

packages/types/src/global-settings.ts

@@ -118,7 +118,6 @@ export const globalSettingsSchema = z.object({
 	allowedMaxCost: z.number().nullish(),
 	autoCondenseContext: z.boolean().optional(),
 	autoCondenseContextPercent: z.number().optional(),
-	maxConcurrentFileReads: z.number().optional(),
 
 	/**
 	 * Whether to include current time in the environment details
@@ -172,7 +171,6 @@ export const globalSettingsSchema = z.object({
 	maxWorkspaceFiles: z.number().optional(),
 	showRooIgnoredFiles: z.boolean().optional(),
 	enableSubfolderRules: z.boolean().optional(),
-	maxReadFileLine: z.number().optional(),
 	maxImageFileSize: z.number().optional(),
 	maxTotalImageSize: z.number().optional(),
 
@@ -382,7 +380,6 @@ export const EVALS_SETTINGS: RooCodeSettings = {
 	maxWorkspaceFiles: 200,
 	maxGitStatusFiles: 20,
 	showRooIgnoredFiles: true,
-	maxReadFileLine: -1, // -1 to enable full file reading.
 
 	includeDiagnosticMessages: true,
 	maxDiagnosticMessages: 50,

packages/types/src/telemetry.ts

@@ -73,6 +73,7 @@ export enum TelemetryEventName {
 	CODE_INDEX_ERROR = "Code Index Error",
 	TELEMETRY_SETTINGS_CHANGED = "Telemetry Settings Changed",
 	MODEL_CACHE_EMPTY_RESPONSE = "Model Cache Empty Response",
+	READ_FILE_LEGACY_FORMAT_USED = "Read File Legacy Format Used",
 }
 
 /**
@@ -203,6 +204,7 @@ export const rooCodeTelemetryEventSchema = z.discriminatedUnion("type", [
 			TelemetryEventName.TAB_SHOWN,
 			TelemetryEventName.MODE_SETTINGS_CHANGED,
 			TelemetryEventName.CUSTOM_MODE_CREATED,
+			TelemetryEventName.READ_FILE_LEGACY_FORMAT_USED,
 		]),
 		properties: telemetryPropertiesSchema,
 	}),

packages/types/src/tool-params.ts

@@ -2,16 +2,96 @@
  * Tool parameter type definitions for native protocol
  */
 
+/**
+ * Read mode for the read_file tool.
+ * - "slice": Simple offset/limit reading (default)
+ * - "indentation": Semantic block extraction based on code structure
+ */
+export type ReadFileMode = "slice" | "indentation"
+
+/**
+ * Indentation-mode configuration for the read_file tool.
+ */
+export interface IndentationParams {
+	/** 1-based line number to anchor indentation extraction (defaults to offset) */
+	anchor_line?: number
+	/** Maximum indentation levels to include above anchor (0 = unlimited) */
+	max_levels?: number
+	/** Include sibling blocks at the same indentation level */
+	include_siblings?: boolean
+	/** Include file header (imports, comments at top) */
+	include_header?: boolean
+	/** Hard cap on lines returned for indentation mode */
+	max_lines?: number
+}
+
+/**
+ * Parameters for the read_file tool (new format).
+ *
+ * NOTE: This is the canonical, single-file-per-call shape.
+ */
+export interface ReadFileParams {
+	/** Path to the file, relative to workspace */
+	path: string
+	/** Reading mode: "slice" (default) or "indentation" */
+	mode?: ReadFileMode
+	/** 1-based line number to start reading from (slice mode, default: 1) */
+	offset?: number
+	/** Maximum number of lines to read (default: 2000) */
+	limit?: number
+	/** Indentation-mode configuration (only used when mode === "indentation") */
+	indentation?: IndentationParams
+}
+
+// ─── Legacy Format Types (Backward Compatibility) ─────────────────────────────
+
+/**
+ * Line range specification for legacy read_file format.
+ * Represents a contiguous range of lines [start, end] (1-based, inclusive).
+ */
 export interface LineRange {
 	start: number
 	end: number
 }
 
+/**
+ * File entry for legacy read_file format.
+ * Supports reading multiple disjoint line ranges from a single file.
+ */
 export interface FileEntry {
+	/** Path to the file, relative to workspace */
 	path: string
+	/** Optional list of line ranges to read (if omitted, reads entire file) */
 	lineRanges?: LineRange[]
 }
 
+/**
+ * Legacy parameters for the read_file tool (pre-refactor format).
+ * Supports reading multiple files in a single call with optional line ranges.
+ *
+ * @deprecated Use ReadFileParams instead. This format is maintained for
+ * backward compatibility with existing chat histories.
+ */
+export interface LegacyReadFileParams {
+	/** Array of file entries to read */
+	files: FileEntry[]
+	/** Discriminant flag for type narrowing */
+	_legacyFormat: true
+}
+
+/**
+ * Union type for read_file tool parameters.
+ * Supports both new single-file format and legacy multi-file format.
+ */
+export type ReadFileToolParams = ReadFileParams | LegacyReadFileParams
+
+/**
+ * Type guard to check if params are in legacy format.
+ */
+export function isLegacyReadFileParams(params: ReadFileToolParams): params is LegacyReadFileParams {
+	return "_legacyFormat" in params && params._legacyFormat === true
+}
+
 export interface Coordinate {
 	x: number
 	y: number

packages/types/src/vscode-extension-host.ts

@@ -65,7 +65,6 @@ export interface ExtensionMessage {
 		| "remoteBrowserEnabled"
 		| "ttsStart"
 		| "ttsStop"
-		| "maxReadFileLine"
 		| "fileSearchResults"
 		| "toggleApiConfigPin"
 		| "acceptInput"
@@ -304,7 +303,6 @@ export type ExtensionState = Pick<
 	| "ttsSpeed"
 	| "soundEnabled"
 	| "soundVolume"
-	| "maxConcurrentFileReads"
 	| "terminalOutputPreviewSize"
 	| "terminalShellIntegrationTimeout"
 	| "terminalShellIntegrationDisabled"
@@ -355,7 +353,6 @@ export type ExtensionState = Pick<
 	maxWorkspaceFiles: number // Maximum number of files to include in current working directory details (0-500)
 	showRooIgnoredFiles: boolean // Whether to show .rooignore'd files in listings
 	enableSubfolderRules: boolean // Whether to load rules from subdirectories
-	maxReadFileLine: number // Maximum number of lines to read from a file before truncating
 	maxImageFileSize: number // Maximum size of image files to process in MB
 	maxTotalImageSize: number // Maximum total size for all images in a single read operation in MB
 
@@ -818,6 +815,7 @@ export interface ClineSayTool {
 	isProtected?: boolean
 	additionalFileCount?: number // Number of additional files in the same read_file request
 	lineNumber?: number
+	startLine?: number // Starting line for read_file operations (for navigation on click)
 	query?: string
 	batchFiles?: Array<{
 		path: string

src/__tests__/command-mentions.spec.ts

@@ -36,7 +36,6 @@ describe("Command Mentions", () => {
 			false, // showRooIgnoredFiles
 			true, // includeDiagnosticMessages
 			50, // maxDiagnosticMessages
-			undefined, // maxReadFileLine
 		)
 	}
 

src/api/providers/__tests__/bedrock-native-tools.spec.ts

@@ -135,23 +135,18 @@ describe("AwsBedrockHandler Native Tool Calling", () => {
 						parameters: {
 							type: "object",
 							properties: {
-								files: {
-									type: "array",
-									items: {
-										type: "object",
-										properties: {
-											path: { type: "string" },
-											line_ranges: {
-												type: ["array", "null"],
-												items: { type: "integer" },
-												description: "Optional line ranges",
-											},
+								path: { type: "string" },
+								indentation: {
+									type: ["object", "null"],
+									properties: {
+										anchor_line: {
+											type: ["integer", "null"],
+											description: "Optional anchor line",
 										},
-										required: ["path", "line_ranges"],
 									},
 								},
 							},
-							required: ["files"],
+							required: ["path"],
 						},
 					},
 				},
@@ -167,15 +162,14 @@ describe("AwsBedrockHandler Native Tool Calling", () => {
 			expect(executeCommandSchema.properties.cwd.type).toBeUndefined()
 			expect(executeCommandSchema.properties.cwd.description).toBe("Working directory (optional)")
 
-			// Second tool: line_ranges should be transformed from type: ["array", "null"] to anyOf
-			// with items moved inside the array variant (required by GPT-5-mini strict schema validation)
+			// Second tool: nested nullable object should be transformed from type: ["object", "null"] to anyOf
 			const readFileSchema = bedrockTools[1].toolSpec.inputSchema.json as any
-			const lineRanges = readFileSchema.properties.files.items.properties.line_ranges
-			expect(lineRanges.anyOf).toEqual([{ type: "array", items: { type: "integer" } }, { type: "null" }])
-			expect(lineRanges.type).toBeUndefined()
-			// items should now be inside the array variant, not at root
-			expect(lineRanges.items).toBeUndefined()
-			expect(lineRanges.description).toBe("Optional line ranges")
+			const indentation = readFileSchema.properties.indentation
+			expect(indentation.anyOf).toBeDefined()
+			expect(indentation.type).toBeUndefined()
+			// Object-level schema properties are preserved at the root, not inside the anyOf object variant
+			expect(indentation.additionalProperties).toBe(false)
+			expect(indentation.properties.anchor_line.anyOf).toEqual([{ type: "integer" }, { type: "null" }])
 		})
 
 		it("should filter non-function tools", () => {