Merge pull request #3 from DaveZheng/fix-tool-execution

fix: enable tool execution with stop sequences, name mapping, and XML suppression

Author: DaveZheng

src/client.ts

@@ -10,6 +10,7 @@ export interface OpenAIChatRequest {
   temperature: number;
   top_p: number;
   stream?: boolean;
+  stop?: string[];
 }
 
 export interface OpenAIChatResponse {

src/parser.test.ts

@@ -3,7 +3,7 @@ import assert from "node:assert";
 import { parseToolCalls, type ParsedToolCall } from "./parser.js";
 
 describe("parseToolCalls", () => {
-  it("parses a single tool call", () => {
+  it("parses a single tool call and maps name to Claude Code format", () => {
     const output = `Let me read that file.
 
 <tool_call>
@@ -15,11 +15,11 @@ describe("parseToolCalls", () => {
     const result = parseToolCalls(output);
     assert.strictEqual(result.text, "Let me read that file.");
     assert.strictEqual(result.toolCalls.length, 1);
-    assert.strictEqual(result.toolCalls[0].name, "read_file");
+    assert.strictEqual(result.toolCalls[0].name, "Read");
     assert.deepStrictEqual(result.toolCalls[0].input, { file_path: "/src/main.ts" });
   });
 
-  it("parses multiple parameters", () => {
+  it("parses multiple parameters and maps edit_file to Edit", () => {
     const output = `<tool_call>
 <function=edit_file>
 <parameter=file_path>/src/main.ts</parameter>
@@ -29,7 +29,7 @@ describe("parseToolCalls", () => {
 </tool_call>`;
 
     const result = parseToolCalls(output);
-    assert.strictEqual(result.toolCalls[0].name, "edit_file");
+    assert.strictEqual(result.toolCalls[0].name, "Edit");
     assert.strictEqual(result.toolCalls[0].input.file_path, "/src/main.ts");
     assert.strictEqual(result.toolCalls[0].input.old_string, "const x = 1;");
     assert.strictEqual(result.toolCalls[0].input.new_string, "const x = 2;");
@@ -46,6 +46,7 @@ line three</parameter>
 </tool_call>`;
 
     const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls[0].name, "Write");
     assert.strictEqual(result.toolCalls[0].input.content, "line one\nline two\nline three");
   });
 
@@ -58,7 +59,7 @@ line three</parameter>
 
     const result = parseToolCalls(output);
     assert.strictEqual(result.toolCalls.length, 1);
-    assert.strictEqual(result.toolCalls[0].name, "read_file");
+    assert.strictEqual(result.toolCalls[0].name, "Read");
   });
 
   it("parses multiple tool calls in one response", () => {
@@ -93,7 +94,7 @@ line three</parameter>
 
     const result = parseToolCalls(output);
     assert.strictEqual(result.toolCalls.length, 1);
-    assert.strictEqual(result.toolCalls[0].name, "read_file");
+    assert.strictEqual(result.toolCalls[0].name, "Read");
     assert.strictEqual(result.toolCalls[0].input.file_path, "/src/main.ts");
   });
 
@@ -111,6 +112,81 @@ line three</parameter>
 
     const result = parseToolCalls(output);
     assert.strictEqual(result.toolCalls.length, 1);
-    assert.strictEqual(result.toolCalls[0].name, "read_file");
+    assert.strictEqual(result.toolCalls[0].name, "Read");
+  });
+
+  it("maps bash tool name to Bash", () => {
+    const output = `<tool_call>
+<function=bash>
+<parameter=command>ls -la</parameter>
+</function>
+</tool_call>`;
+
+    const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls[0].name, "Bash");
+    assert.strictEqual(result.toolCalls[0].input.command, "ls -la");
+  });
+
+  it("maps grep tool name to Grep", () => {
+    const output = `<tool_call>
+<function=grep>
+<parameter=pattern>TODO</parameter>
+<parameter=path>/src</parameter>
+</function>
+</tool_call>`;
+
+    const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls[0].name, "Grep");
+    assert.strictEqual(result.toolCalls[0].input.pattern, "TODO");
+  });
+
+  it("maps glob tool name to Glob", () => {
+    const output = `<tool_call>
+<function=glob>
+<parameter=pattern>**/*.ts</parameter>
+</function>
+</tool_call>`;
+
+    const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls[0].name, "Glob");
+  });
+
+  it("handles stop sequence truncation (missing </tool_call>)", () => {
+    // When stop=["</tool_call>"], the model output ends before the closing tag
+    const output = `Let me check.
+
+<tool_call>
+<function=read_file>
+<parameter=file_path>/src/main.ts</parameter>
+</function>
+`;
+
+    const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls.length, 1);
+    assert.strictEqual(result.toolCalls[0].name, "Read");
+    assert.strictEqual(result.toolCalls[0].input.file_path, "/src/main.ts");
+  });
+
+  it("handles stop sequence truncation (missing </function> and </tool_call>)", () => {
+    // Extreme truncation — stop sequence fired before </function>
+    const output = `<tool_call>
+<function=bash>
+<parameter=command>echo hello</parameter>`;
+
+    const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls.length, 1);
+    assert.strictEqual(result.toolCalls[0].name, "Bash");
+    assert.strictEqual(result.toolCalls[0].input.command, "echo hello");
+  });
+
+  it("passes through unknown tool names unchanged", () => {
+    const output = `<tool_call>
+<function=custom_tool>
+<parameter=arg>value</parameter>
+</function>
+</tool_call>`;
+
+    const result = parseToolCalls(output);
+    assert.strictEqual(result.toolCalls[0].name, "custom_tool");
   });
 });

src/parser.ts

@@ -8,6 +8,44 @@ export interface ParseResult {
   toolCalls: ParsedToolCall[];
 }
 
+/**
+ * Map local tool names to Claude Code tool names.
+ * The local model calls tools by the names in our injected definitions,
+ * but Claude Code expects its own tool names.
+ */
+const TOOL_NAME_MAP: Record<string, string> = {
+  read_file: "Read",
+  write_file: "Write",
+  edit_file: "Edit",
+  bash: "Bash",
+  glob: "Glob",
+  grep: "Grep",
+};
+
+/**
+ * Map local parameter names to Claude Code parameter names where they differ.
+ */
+const PARAM_NAME_MAP: Record<string, Record<string, string>> = {
+  Read: { file_path: "file_path", offset: "offset", limit: "limit" },
+  Write: { file_path: "file_path", content: "content" },
+  Edit: { file_path: "file_path", old_string: "old_string", new_string: "new_string" },
+  Bash: { command: "command" },
+  Glob: { pattern: "pattern", path: "path" },
+  Grep: { pattern: "pattern", path: "path" },
+};
+
+function mapToolCall(name: string, input: Record<string, string>): ParsedToolCall {
+  const mappedName = TOOL_NAME_MAP[name] ?? name;
+  const paramMap = PARAM_NAME_MAP[mappedName];
+  if (!paramMap) return { name: mappedName, input };
+
+  const mappedInput: Record<string, string> = {};
+  for (const [key, value] of Object.entries(input)) {
+    mappedInput[paramMap[key] ?? key] = value;
+  }
+  return { name: mappedName, input: mappedInput };
+}
+
 export function parseToolCalls(output: string): ParseResult {
   const toolCalls: ParsedToolCall[] = [];
 
@@ -25,9 +63,16 @@ export function parseToolCalls(output: string): ParseResult {
   normalized = normalized.replace(new RegExp(sentinel.replace(/\0/g, "\\0"), "g"), "");
 
   // Normalize: handle missing </tool_call> closing tag
-  // Insert </tool_call> after </function> if not already followed by one
+  // Also handles stop sequence cutting off </tool_call> — the model stops
+  // generating at </tool_call> so it may not appear in the output
   normalized = normalized.replace(/<\/function>\s*(?!<\/tool_call>)/g, "</function>\n</tool_call>");
 
+  // Handle truncated tool calls where </function> is also missing
+  // (stop sequence fired mid-generation). Close any unclosed function blocks.
+  if (normalized.includes("<function=") && !normalized.includes("</function>")) {
+    normalized += "\n</function>\n</tool_call>";
+  }
+
   // Extract all tool call blocks
   const blockRegex = /<tool_call>\s*<function=([^>]+)>([\s\S]*?)<\/function>\s*<\/tool_call>/g;
   let match: RegExpExecArray | null;
@@ -52,7 +97,7 @@ export function parseToolCalls(output: string): ParseResult {
       input[paramMatch[1].trim()] = paramMatch[2].trim();
     }
 
-    toolCalls.push({ name, input });
+    toolCalls.push(mapToolCall(name, input));
   }
 
   const text = textParts.join("").trim();

src/translate-request.ts

@@ -118,5 +118,6 @@ export function translateRequest(req: AnthropicRequest, mlxModel: string): OpenA
     temperature: 0.7,
     top_p: 0.95,
     stream: req.stream,
+    stop: ["</tool_call>"],
   };
 }