[BUG] Agent/Explore subagent crashes with "Cannot read properties of undefined (reading 'input_tokens')"

Found 1 possible duplicate issue:

1. https://github.com/anthropics/claude-code/issues/30620

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🤖 Generated with Claude Code

Is there any solution for this already? It also happens when running claude code with minimax2.7 through openrouter

was happening to me after switching to minimax2.7, switched back to 2.5 and it seems to be working fine.

+1， I also encountered this problem; my model is GLM5.

+1, and it seems to occur more often when execute complex tasks.

+1, exactly same for me, minimax 2.7 keeps breaking

same for me as well, minimax 2.7 keeps breaking

I am also getting the same when using subagents within a session. I am on MacOS Tahoe, so it's not exclusive to Windows.

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

Solution that worked for me

Use a proxy. this is the script I used:

#!/usr/bin/env node
const http = require("http");
const https = require("https");

const PORT = 3099;

function patchUsage(usage) {
  if (!usage || typeof usage !== "object") return usage;
  usage.input_tokens = usage.input_tokens || usage.prompt_tokens || 0;
  usage.output_tokens = usage.output_tokens || usage.completion_tokens || 0;
  usage.cache_read_input_tokens = usage.cache_read_input_tokens || 0;
  usage.cache_creation_input_tokens = usage.cache_creation_input_tokens || 0;
  usage.cache_creation = usage.cache_creation || 0;
  return usage;
}

function patchSSELine(line) {
  if (!line.startsWith("data: ")) return line;
  const payload = line.slice(6).trim();
  if (payload === "[DONE]") return line;
  try {
    const obj = JSON.parse(payload);
    if (obj.usage) obj.usage = patchUsage(obj.usage);
    if (obj.message && obj.message.usage)
      obj.message.usage = patchUsage(obj.message.usage);
    return "data: " + JSON.stringify(obj);
  } catch {
    return line;
  }
}

const server = http.createServer((req, res) => {
  const options = {
    hostname: "openrouter.ai",
    port: 443,
    path: "/api" + req.url,
    method: req.method,
    headers: {
      ...req.headers,
      host: "openrouter.ai",
      "accept-encoding": "identity",
    },
  };

  const upstream = https.request(options, (upRes) => {
    const isSSE = (upRes.headers["content-type"] || "").includes(
      "text/event-stream",
    );

    res.writeHead(upRes.statusCode, upRes.headers);

    if (!isSSE) {
      upRes.pipe(res);
      return;
    }

    // SSE: patch each line
    let buffer = "";
    upRes.on("data", (chunk) => {
      buffer += chunk.toString();
      const lines = buffer.split("\n");
      buffer = lines.pop(); // keep incomplete line
      for (const line of lines) {
        res.write(patchSSELine(line) + "\n");
      }
    });
    upRes.on("end", () => {
      if (buffer) res.write(patchSSELine(buffer) + "\n");
      res.end();
    });
  });

  upstream.on("error", (err) => {
    console.error("[proxy] error:", err.message);
    res.writeHead(502);
    res.end(JSON.stringify({ error: err.message }));
  });

  req.pipe(upstream);
});

server.listen(PORT, "127.0.0.1", () => {});

And then, in my .zshrc I am using a custom command:

openclaude() {
  # Start proxy if not already running
  if ! lsof -i :3099 -t &>/dev/null; then
    node ~/.claude/proxy.js &
    PROXY_PID=$!
    echo "[proxy] started (pid $PROXY_PID)"
    sleep 0.5  # give it a moment to bind
  else
    PROXY_PID=""
    echo "[proxy] already running, reusing"
  fi

  ANTHROPIC_BASE_URL="http://localhost:3099" \
  ANTHROPIC_AUTH_TOKEN="$OPENROUTER_API_KEY" \
  ANTHROPIC_API_KEY="" \
  ANTHROPIC_MODEL="minimax/minimax-m2.7" \
  ANTHROPIC_DEFAULT_OPUS_MODEL="minimax/minimax-m2.7" \
  ANTHROPIC_DEFAULT_SONNET_MODEL="minimax/minimax-m2.7" \
  ANTHROPIC_DEFAULT_HAIKU_MODEL="minimax/minimax-m2.7" \
  CLAUDE_CODE_SUBAGENT_MODEL="minimax/minimax-m2.7" \
  ENABLE_TOOL_SEARCH=true \
  claude --tools "Agent,AskUserQuestion,Bash,Edit,Glob,Grep,LSP,Read,Skill,TaskCreate,TaskGet,TaskList,TaskUpdate,TaskStop,TaskOutput,TodoWrite,WebFetch,WebSearch,Write" "$@"

}

This way, it worked perfectly fine.

NOTE: i have shifted to using kimi 2.6 using Ollama, and this is what worked for me before moving to ollama. Overall, no issues in Ollama. Posting it here for folks who still wanna use Open Router, or something else that might be causing the same error message for them.

In case the above does not work for you, make sure to feed it to claude and ask it to fix it for you. Make sure to check your paths and stuff

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.