Agents: preserve unsafe integer tool args in Ollama stream

src/agents/ollama-stream.test.ts

@@ -244,6 +244,40 @@ describe("parseNdjsonStream", () => {
     // Final done:true chunk has no tool_calls
     expect(chunks[2].message.tool_calls).toBeUndefined();
   });
+
+  it("preserves unsafe integer tool arguments as exact strings", async () => {
+    const reader = mockNdjsonReader([
+      '{"model":"m","created_at":"t","message":{"role":"assistant","content":"","tool_calls":[{"function":{"name":"send","arguments":{"target":1234567890123456789,"nested":{"thread":9223372036854775807}}}}]},"done":false}',
+    ]);
+
+    const chunks = [];
+    for await (const chunk of parseNdjsonStream(reader)) {
+      chunks.push(chunk);
+    }
+
+    const args = chunks[0]?.message.tool_calls?.[0]?.function.arguments as
+      | { target?: unknown; nested?: { thread?: unknown } }
+      | undefined;
+    expect(args?.target).toBe("1234567890123456789");
+    expect(args?.nested?.thread).toBe("9223372036854775807");
+  });
+
+  it("keeps safe integer tool arguments as numbers", async () => {
+    const reader = mockNdjsonReader([
+      '{"model":"m","created_at":"t","message":{"role":"assistant","content":"","tool_calls":[{"function":{"name":"send","arguments":{"retries":3,"delayMs":2500}}}]},"done":false}',
+    ]);
+
+    const chunks = [];
+    for await (const chunk of parseNdjsonStream(reader)) {
+      chunks.push(chunk);
+    }
+
+    const args = chunks[0]?.message.tool_calls?.[0]?.function.arguments as
+      | { retries?: unknown; delayMs?: unknown }
+      | undefined;
+    expect(args?.retries).toBe(3);
+    expect(args?.delayMs).toBe(2500);
+  });
 });
 
 describe("createOllamaStreamFn", () => {

src/agents/ollama-stream.ts

@@ -49,6 +49,130 @@ interface OllamaToolCall {
   };
 }
 
+const MAX_SAFE_INTEGER_ABS_STR = String(Number.MAX_SAFE_INTEGER);
+
+function isAsciiDigit(ch: string | undefined): boolean {
+  return ch !== undefined && ch >= "0" && ch <= "9";
+}
+
+function parseJsonNumberToken(
+  input: string,
+  start: number,
+): { token: string; end: number; isInteger: boolean } | null {
+  let idx = start;
+  if (input[idx] === "-") {
+    idx += 1;
+  }
+  if (idx >= input.length) {
+    return null;
+  }
+
+  if (input[idx] === "0") {
+    idx += 1;
+  } else if (isAsciiDigit(input[idx]) && input[idx] !== "0") {
+    while (isAsciiDigit(input[idx])) {
+      idx += 1;
+    }
+  } else {
+    return null;
+  }
+
+  let isInteger = true;
+  if (input[idx] === ".") {
+    isInteger = false;
+    idx += 1;
+    if (!isAsciiDigit(input[idx])) {
+      return null;
+    }
+    while (isAsciiDigit(input[idx])) {
+      idx += 1;
+    }
+  }
+
+  if (input[idx] === "e" || input[idx] === "E") {
+    isInteger = false;
+    idx += 1;
+    if (input[idx] === "+" || input[idx] === "-") {
+      idx += 1;
+    }
+    if (!isAsciiDigit(input[idx])) {
+      return null;
+    }
+    while (isAsciiDigit(input[idx])) {
+      idx += 1;
+    }
+  }
+
+  return {
+    token: input.slice(start, idx),
+    end: idx,
+    isInteger,
+  };
+}
+
+function isUnsafeIntegerLiteral(token: string): boolean {
+  const digits = token[0] === "-" ? token.slice(1) : token;
+  if (digits.length < MAX_SAFE_INTEGER_ABS_STR.length) {
+    return false;
+  }
+  if (digits.length > MAX_SAFE_INTEGER_ABS_STR.length) {
+    return true;
+  }
+  return digits > MAX_SAFE_INTEGER_ABS_STR;
+}
+
+function quoteUnsafeIntegerLiterals(input: string): string {
+  let out = "";
+  let inString = false;
+  let escaped = false;
+  let idx = 0;
+
+  while (idx < input.length) {
+    const ch = input[idx] ?? "";
+    if (inString) {
+      out += ch;
+      if (escaped) {
+        escaped = false;
+      } else if (ch === "\\") {
+        escaped = true;
+      } else if (ch === '"') {
+        inString = false;
+      }
+      idx += 1;
+      continue;
+    }
+
+    if (ch === '"') {
+      inString = true;
+      out += ch;
+      idx += 1;
+      continue;
+    }
+
+    if (ch === "-" || isAsciiDigit(ch)) {
+      const parsed = parseJsonNumberToken(input, idx);
+      if (parsed) {
+        if (parsed.isInteger && isUnsafeIntegerLiteral(parsed.token)) {
+          out += `"${parsed.token}"`;
+        } else {
+          out += parsed.token;
+        }
+        idx = parsed.end;
+        continue;
+      }
+    }
+
+    out += ch;
+    idx += 1;
+  }
+
+  return out;
+}
+
+function parseJsonPreservingUnsafeIntegers(input: string): unknown {
+  return JSON.parse(quoteUnsafeIntegerLiterals(input)) as unknown;
+}
+
 // ── Ollama /api/chat response types ─────────────────────────────────────────
 
 interface OllamaChatResponse {
@@ -262,7 +386,7 @@ export async function* parseNdjsonStream(
         continue;
       }
       try {
-        yield JSON.parse(trimmed) as OllamaChatResponse;
+        yield parseJsonPreservingUnsafeIntegers(trimmed) as OllamaChatResponse;
       } catch {
         log.warn(`Skipping malformed NDJSON line: ${trimmed.slice(0, 120)}`);
       }
@@ -271,7 +395,7 @@ export async function* parseNdjsonStream(
 
   if (buffer.trim()) {
     try {
-      yield JSON.parse(buffer.trim()) as OllamaChatResponse;
+      yield parseJsonPreservingUnsafeIntegers(buffer.trim()) as OllamaChatResponse;
     } catch {
       log.warn(`Skipping malformed trailing data: ${buffer.trim().slice(0, 120)}`);
     }