Fix strict tool schemas for nullable objects

src/api/providers/__tests__/base-provider.spec.ts

@@ -176,6 +176,25 @@ describe("BaseProvider", () => {
 			expect(result.additionalProperties).toBe(false)
 			expect(result.required).toEqual([])
 		})
+
+		it("should inject required for nullable object schemas (type: ['object','null'])", () => {
+			const schema = {
+				type: "object",
+				properties: {
+					indentation: {
+						type: ["object", "null"],
+						properties: {
+							anchorLine: { type: ["integer", "null"] },
+							maxLevels: { type: ["integer", "null"] },
+						},
+						additionalProperties: false,
+					},
+				},
+			}
+
+			const result = provider.testConvertToolSchemaForOpenAI(schema)
+			expect(result.properties.indentation.required).toEqual(["anchorLine", "maxLevels"])
+		})
 	})
 
 	describe("convertToolsForOpenAI", () => {

src/api/providers/__tests__/openai-codex-native-tool-calls.spec.ts

@@ -98,4 +98,75 @@ describe("OpenAiCodexHandler native tool calls", () => {
 			name: "attempt_completion",
 		})
 	})
+
+	it("normalizes nullable object schemas for strict tools (read_file indentation.anchorLine regression)", async () => {
+		vi.spyOn(openAiCodexOAuthManager, "getAccessToken").mockResolvedValue("test-token")
+		vi.spyOn(openAiCodexOAuthManager, "getAccountId").mockResolvedValue("acct_test")
+
+		let capturedBody: any
+		;(handler as any).client = {
+			responses: {
+				create: vi.fn().mockImplementation(async (body: any) => {
+					capturedBody = body
+					return {
+						async *[Symbol.asyncIterator]() {
+							yield {
+								type: "response.done",
+								response: {
+									output: [{ type: "message", content: [{ type: "output_text", text: "ok" }] }],
+									usage: { input_tokens: 1, output_tokens: 1 },
+								},
+							}
+						},
+					}
+				}),
+			},
+		}
+
+		const readFileLikeTool = {
+			type: "function" as const,
+			function: {
+				name: "read_file",
+				description: "Read files",
+				parameters: {
+					type: "object",
+					properties: {
+						files: {
+							type: "array",
+							items: {
+								type: "object",
+								properties: {
+									path: { type: "string" },
+									indentation: {
+										type: ["object", "null"],
+										properties: {
+											anchorLine: { type: ["integer", "null"] },
+											maxLevels: { type: ["integer", "null"] },
+										},
+										additionalProperties: false,
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		const stream = handler.createMessage("system", [{ role: "user", content: "hello" } as any], {
+			taskId: "t",
+			toolProtocol: "native",
+			tools: [readFileLikeTool as any],
+		})
+		for await (const _ of stream) {
+			// consume
+		}
+
+		const tool = capturedBody.tools?.[0]
+		expect(tool).toBeDefined()
+		expect(tool.strict).toBe(true)
+		const indentation = tool.parameters.properties.files.items.properties.indentation
+		// Critical: nullable-object schemas must still have required containing every key in properties.
+		expect(indentation.required).toEqual(["anchorLine", "maxLevels"])
+	})
 })

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

@@ -218,6 +218,83 @@ describe("OpenAiNativeHandler MCP tool schema handling", () => {
 		expect(tool.parameters.required).toEqual(["path", "encoding"]) // Should have all properties as required
 	})
 
+	it("should inject required for nullable object schemas (read_file indentation.anchorLine regression)", async () => {
+		let capturedRequestBody: any
+
+		const handler = new OpenAiNativeHandler({
+			openAiNativeApiKey: "test-key",
+			apiModelId: "gpt-4o",
+		} as ApiHandlerOptions)
+
+		// Mock the responses API call
+		const mockClient = {
+			responses: {
+				create: vi.fn().mockImplementation((body: any) => {
+					capturedRequestBody = body
+					return {
+						[Symbol.asyncIterator]: async function* () {
+							yield {
+								type: "response.done",
+								response: {
+									output: [{ type: "message", content: [{ type: "output_text", text: "test" }] }],
+									usage: { input_tokens: 10, output_tokens: 5 },
+								},
+							}
+						},
+					}
+				}),
+			},
+		}
+		;(handler as any).client = mockClient
+
+		const tools: OpenAI.Chat.ChatCompletionTool[] = [
+			{
+				type: "function",
+				function: {
+					name: "read_file",
+					description: "Read files",
+					parameters: {
+						type: "object",
+						properties: {
+							files: {
+								type: "array",
+								items: {
+									type: "object",
+									properties: {
+										path: { type: "string" },
+										indentation: {
+											type: ["object", "null"],
+											properties: {
+												anchorLine: { type: ["integer", "null"] },
+												maxLevels: { type: ["integer", "null"] },
+											},
+											additionalProperties: false,
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		]
+
+		const stream = handler.createMessage("system prompt", [], {
+			taskId: "test-task-id",
+			tools,
+			toolProtocol: "native" as const,
+		})
+
+		for await (const _ of stream) {
+			// consume
+		}
+
+		const tool = capturedRequestBody.tools[0]
+		expect(tool.strict).toBe(true)
+		const indentation = tool.parameters.properties.files.items.properties.indentation
+		expect(indentation.required).toEqual(["anchorLine", "maxLevels"])
+	})
+
 	it("should recursively add additionalProperties: false to nested objects in MCP tools", async () => {
 		let capturedRequestBody: any
 

src/api/providers/base-provider.ts

@@ -61,7 +61,17 @@ export abstract class BaseProvider implements ApiHandler {
 	 * This matches the behavior of ensureAllRequired in openai-native.ts
 	 */
 	protected convertToolSchemaForOpenAI(schema: any): any {
-		if (!schema || typeof schema !== "object" || schema.type !== "object") {
+		const isObjectLikeSchema = (candidate: any): boolean => {
+			if (!candidate || typeof candidate !== "object") return false
+			const type = candidate.type
+			return (
+				type === "object" ||
+				(Array.isArray(type) && type.includes("object")) ||
+				candidate.properties !== undefined
+			)
+		}
+
+		if (!isObjectLikeSchema(schema)) {
 			return schema
 		}
 
@@ -89,19 +99,39 @@ export abstract class BaseProvider implements ApiHandler {
 					prop.type = nonNullTypes.length === 1 ? nonNullTypes[0] : nonNullTypes
 				}
 
-				// Recursively process nested objects
-				if (prop && prop.type === "object") {
+				// Recursively process nested objects (including nullable objects)
+				if (isObjectLikeSchema(prop)) {
 					newProps[key] = this.convertToolSchemaForOpenAI(prop)
-				} else if (prop && prop.type === "array" && prop.items?.type === "object") {
+				} else if (prop && prop.type === "array" && prop.items && isObjectLikeSchema(prop.items)) {
 					newProps[key] = {
 						...prop,
-						items: this.convertToolSchemaForOpenAI(prop.items),
+						items: Array.isArray(prop.items)
+							? prop.items.map((i: any) => this.convertToolSchemaForOpenAI(i))
+							: this.convertToolSchemaForOpenAI(prop.items),
 					}
 				}
 			}
 			result.properties = newProps
 		}
 
+		// Also recurse through unions if present
+		if (Array.isArray((result as any).anyOf)) {
+			;(result as any).anyOf = (result as any).anyOf.map((s: any) => this.convertToolSchemaForOpenAI(s))
+		}
+		if (Array.isArray((result as any).oneOf)) {
+			;(result as any).oneOf = (result as any).oneOf.map((s: any) => this.convertToolSchemaForOpenAI(s))
+		}
+		if (Array.isArray((result as any).allOf)) {
+			;(result as any).allOf = (result as any).allOf.map((s: any) => this.convertToolSchemaForOpenAI(s))
+		}
+
+		if ((result as any).type === "array" && (result as any).items) {
+			const items = (result as any).items
+			;(result as any).items = Array.isArray(items)
+				? items.map((i: any) => this.convertToolSchemaForOpenAI(i))
+				: this.convertToolSchemaForOpenAI(items)
+		}
+
 		return result
 	}
 

src/api/providers/openai-codex.ts

@@ -207,8 +207,31 @@ export class OpenAiCodexHandler extends BaseProvider implements SingleCompletion
 		reasoningEffort: ReasoningEffortExtended | undefined,
 		metadata?: ApiHandlerCreateMessageMetadata,
 	): any {
+		const isObjectLikeSchema = (schema: any): boolean => {
+			if (!schema || typeof schema !== "object") return false
+			const type = schema.type
+			return (
+				type === "object" || (Array.isArray(type) && type.includes("object")) || schema.properties !== undefined
+			)
+		}
+
 		const ensureAllRequired = (schema: any): any => {
-			if (!schema || typeof schema !== "object" || schema.type !== "object") {
+			// Only object-like schemas need "required" injection for OpenAI strict schemas.
+			if (!isObjectLikeSchema(schema)) {
+				// Still recurse into anyOf/oneOf/allOf arrays if present.
+				if (schema && typeof schema === "object") {
+					const out = { ...schema }
+					if (Array.isArray(out.anyOf)) out.anyOf = out.anyOf.map(ensureAllRequired)
+					if (Array.isArray(out.oneOf)) out.oneOf = out.oneOf.map(ensureAllRequired)
+					if (Array.isArray(out.allOf)) out.allOf = out.allOf.map(ensureAllRequired)
+					// Recurse into array item schemas too.
+					if (out.type === "array" && out.items) {
+						out.items = Array.isArray(out.items)
+							? out.items.map(ensureAllRequired)
+							: ensureAllRequired(out.items)
+					}
+					return out
+				}
 				return schema
 			}
 
@@ -224,28 +247,34 @@ export class OpenAiCodexHandler extends BaseProvider implements SingleCompletion
 				const newProps = { ...result.properties }
 				for (const key of allKeys) {
 					const prop = newProps[key]
-					if (prop.type === "object") {
+					if (prop && typeof prop === "object") {
+						// Recurse for nested object schemas, nullable object schemas (type: ["object","null"]),
+						// union schemas (anyOf), and arrays-of-objects.
 						newProps[key] = ensureAllRequired(prop)
-					} else if (prop.type === "array" && prop.items?.type === "object") {
-						newProps[key] = {
-							...prop,
-							items: ensureAllRequired(prop.items),
-						}
 					}
 				}
 				result.properties = newProps
 			}
 
+			if (Array.isArray(result.anyOf)) result.anyOf = result.anyOf.map(ensureAllRequired)
+			if (Array.isArray(result.oneOf)) result.oneOf = result.oneOf.map(ensureAllRequired)
+			if (Array.isArray(result.allOf)) result.allOf = result.allOf.map(ensureAllRequired)
+			if (result.type === "array" && result.items) {
+				result.items = Array.isArray(result.items)
+					? result.items.map(ensureAllRequired)
+					: ensureAllRequired(result.items)
+			}
+
 			return result
 		}
 
 		const ensureAdditionalPropertiesFalse = (schema: any): any => {
-			if (!schema || typeof schema !== "object" || schema.type !== "object") {
+			if (!schema || typeof schema !== "object") {
 				return schema
 			}
 
 			const result = { ...schema }
-			if (result.additionalProperties !== false) {
+			if (isObjectLikeSchema(result) && result.additionalProperties !== false) {
 				result.additionalProperties = false
 			}
 
@@ -253,18 +282,23 @@ export class OpenAiCodexHandler extends BaseProvider implements SingleCompletion
 				const newProps = { ...result.properties }
 				for (const key of Object.keys(result.properties)) {
 					const prop = newProps[key]
-					if (prop && prop.type === "object") {
+					if (prop && typeof prop === "object") {
 						newProps[key] = ensureAdditionalPropertiesFalse(prop)
-					} else if (prop && prop.type === "array" && prop.items?.type === "object") {
-						newProps[key] = {
-							...prop,
-							items: ensureAdditionalPropertiesFalse(prop.items),
-						}
 					}
 				}
 				result.properties = newProps
 			}
 
+			if (Array.isArray(result.anyOf)) result.anyOf = result.anyOf.map(ensureAdditionalPropertiesFalse)
+			if (Array.isArray(result.oneOf)) result.oneOf = result.oneOf.map(ensureAdditionalPropertiesFalse)
+			if (Array.isArray(result.allOf)) result.allOf = result.allOf.map(ensureAdditionalPropertiesFalse)
+
+			if (result.type === "array" && result.items) {
+				result.items = Array.isArray(result.items)
+					? result.items.map(ensureAdditionalPropertiesFalse)
+					: ensureAdditionalPropertiesFalse(result.items)
+			}
+
 			return result
 		}
 

src/api/providers/openai-native.ts

@@ -216,17 +216,37 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 		reasoningEffort: ReasoningEffortExtended | undefined,
 		metadata?: ApiHandlerCreateMessageMetadata,
 	): any {
-		// Ensure all properties are in the required array for OpenAI's strict mode
-		// This recursively processes nested objects and array items
+		const isObjectLikeSchema = (schema: any): boolean => {
+			if (!schema || typeof schema !== "object") return false
+			const type = schema.type
+			return (
+				type === "object" || (Array.isArray(type) && type.includes("object")) || schema.properties !== undefined
+			)
+		}
+
+		// Ensure all properties are in the required array for OpenAI's strict mode.
+		// This recursively processes nested objects and array items.
+		// IMPORTANT: must handle nullable objects (type: ["object","null"]).
 		const ensureAllRequired = (schema: any): any => {
-			if (!schema || typeof schema !== "object" || schema.type !== "object") {
+			if (!isObjectLikeSchema(schema)) {
+				if (schema && typeof schema === "object") {
+					const out = { ...schema }
+					if (Array.isArray(out.anyOf)) out.anyOf = out.anyOf.map(ensureAllRequired)
+					if (Array.isArray(out.oneOf)) out.oneOf = out.oneOf.map(ensureAllRequired)
+					if (Array.isArray(out.allOf)) out.allOf = out.allOf.map(ensureAllRequired)
+					if (out.type === "array" && out.items) {
+						out.items = Array.isArray(out.items)
+							? out.items.map(ensureAllRequired)
+							: ensureAllRequired(out.items)
+					}
+					return out
+				}
 				return schema
 			}
 
 			const result = { ...schema }
 
-			// OpenAI Responses API requires additionalProperties: false on all object schemas
-			// Only add if not already set to false (to avoid unnecessary mutations)
+			// OpenAI Responses API requires additionalProperties: false on all object schemas.
 			if (result.additionalProperties !== false) {
 				result.additionalProperties = false
 			}
@@ -235,58 +255,61 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 				const allKeys = Object.keys(result.properties)
 				result.required = allKeys
 
-				// Recursively process nested objects
 				const newProps = { ...result.properties }
 				for (const key of allKeys) {
 					const prop = newProps[key]
-					if (prop.type === "object") {
+					if (prop && typeof prop === "object") {
 						newProps[key] = ensureAllRequired(prop)
-					} else if (prop.type === "array" && prop.items?.type === "object") {
-						newProps[key] = {
-							...prop,
-							items: ensureAllRequired(prop.items),
-						}
 					}
 				}
 				result.properties = newProps
 			}
 
+			if (Array.isArray(result.anyOf)) result.anyOf = result.anyOf.map(ensureAllRequired)
+			if (Array.isArray(result.oneOf)) result.oneOf = result.oneOf.map(ensureAllRequired)
+			if (Array.isArray(result.allOf)) result.allOf = result.allOf.map(ensureAllRequired)
+			if (result.type === "array" && result.items) {
+				result.items = Array.isArray(result.items)
+					? result.items.map(ensureAllRequired)
+					: ensureAllRequired(result.items)
+			}
+
 			return result
 		}
 
-		// Adds additionalProperties: false to all object schemas recursively
-		// without modifying required array. Used for MCP tools with strict: false
-		// to comply with OpenAI Responses API requirements.
+		// Adds additionalProperties: false to all object-like schemas recursively without modifying required.
+		// Used for MCP tools with strict: false to comply with OpenAI Responses API requirements.
 		const ensureAdditionalPropertiesFalse = (schema: any): any => {
-			if (!schema || typeof schema !== "object" || schema.type !== "object") {
+			if (!schema || typeof schema !== "object") {
 				return schema
 			}
 
 			const result = { ...schema }
-
-			// OpenAI Responses API requires additionalProperties: false on all object schemas
-			// Only add if not already set to false (to avoid unnecessary mutations)
-			if (result.additionalProperties !== false) {
+			if (isObjectLikeSchema(result) && result.additionalProperties !== false) {
 				result.additionalProperties = false
 			}
 
 			if (result.properties) {
-				// Recursively process nested objects
 				const newProps = { ...result.properties }
 				for (const key of Object.keys(result.properties)) {
 					const prop = newProps[key]
-					if (prop && prop.type === "object") {
+					if (prop && typeof prop === "object") {
 						newProps[key] = ensureAdditionalPropertiesFalse(prop)
-					} else if (prop && prop.type === "array" && prop.items?.type === "object") {
-						newProps[key] = {
-							...prop,
-							items: ensureAdditionalPropertiesFalse(prop.items),
-						}
 					}
 				}
 				result.properties = newProps
 			}
 
+			if (Array.isArray(result.anyOf)) result.anyOf = result.anyOf.map(ensureAdditionalPropertiesFalse)
+			if (Array.isArray(result.oneOf)) result.oneOf = result.oneOf.map(ensureAdditionalPropertiesFalse)
+			if (Array.isArray(result.allOf)) result.allOf = result.allOf.map(ensureAdditionalPropertiesFalse)
+
+			if (result.type === "array" && result.items) {
+				result.items = Array.isArray(result.items)
+					? result.items.map(ensureAdditionalPropertiesFalse)
+					: ensureAdditionalPropertiesFalse(result.items)
+			}
+
 			return result
 		}