Approval resume validates null-widened history args, so approved tools fail with repairToolInput: false #2073

import { chat, toolDefinition, maxIterations } from "@tanstack/ai";
import { openaiText } from "@tanstack/ai-openai";

const bookFlight = toolDefinition({
  name: "bookFlight",
  description: "Book a flight",
  inputSchema: {
    type: "object",
    properties: { destination: { type: "string" }, date: { type: "string" } },
    required: ["destination"],
    additionalProperties: false,
  },
  needsApproval: true,
}).server(async () => ({ booked: true }));

const threadId = `repro-${Date.now()}`;
const user = { role: "user", content: "Book a flight to Tokyo. I have no date yet." };

// Run 1: pauses for approval.
const run1 = [];
for await (const chunk of chat({
  adapter: openaiText("gpt-4o-mini"),
  messages: [user],
  tools: [bookFlight],
  threadId,
  runId: "r1",
})) run1.push(chunk);

const { toolCallId } = run1.find((e) => e.type === "TOOL_CALL_START");
const streamedArgs = run1
  .filter((e) => e.type === "TOOL_CALL_ARGS" && e.toolCallId === toolCallId)
  .map((e) => e.delta)
  .join(""); // {"destination":"Tokyo","date":null}

// Run 2: approve, with the history a client rebuilt from the stream.
for await (const chunk of chat({
  adapter: openaiText("gpt-4o-mini"),
  messages: [
    user,
    {
      role: "assistant",
      content: "",
      toolCalls: [
        { id: toolCallId, type: "function", function: { name: "bookFlight", arguments: streamedArgs } },
      ],
    },
  ],
  tools: [bookFlight],
  threadId,
  runId: "r2",
  parentRunId: "r1",
  resume: [{ interruptId: `approval_${toolCallId}`, status: "resolved", payload: { approved: true } }],
  repairToolInput: false,
  agentLoopStrategy: maxIterations(3),
})) {
  if (chunk.type === "TOOL_CALL_RESULT") console.log(chunk.content); // input validation error
}