openai/codex-plugin-cc · error · Error

This Codex version does not support Claude session transfer.

Error message

This Codex version does not support Claude session transfer. Update Codex with `npm install -g @openai/codex@latest`, then retry.

What it means

Thrown by importExternalAgentSession when the RPC call 'externalAgentConfig/import' is rejected with rpcCode -32601 (JSON-RPC method not found). That code means the connected Codex app-server does not implement the external-agent import method, i.e. the installed Codex is older than the feature. The error is wrapped with { cause: error } preserving the original RPC failure.

Source

Thrown at plugins/codex/scripts/lib/codex.mjs:1073

  });
}

export async function importExternalAgentSession(cwd, options = {}) {
  const availability = getCodexAvailability(cwd);
  if (!availability.available) {
    throw new Error("Codex CLI is not installed or is missing required runtime support. Install it with `npm install -g @openai/codex`, then rerun `/codex:setup`.");
  }
  if (!options.sourcePath) {
    throw new Error("A Claude session source path is required.");
  }

  return withDirectAppServer(cwd, async (client) => {
    emitProgress(options.onProgress, "Importing Claude session into Codex.", "transferring");
    try {
      await requestExternalAgentSessionImport(client, externalAgentSessionMigration(options.sourcePath, cwd));
    } catch (error) {
      if (error?.rpcCode === -32601) {
        throw new Error(
          "This Codex version does not support Claude session transfer. Update Codex with `npm install -g @openai/codex@latest`, then retry.",
          { cause: error }
        );
      }
      throw error;
    }
    const threadId = importedThreadIdForSource(options.sourcePath);
    if (!threadId) {
      const stderr = cleanCodexStderr(client.stderr);
      throw new Error(
        `Codex reported that the Claude import completed, but did not record an imported thread.${stderr ? `\n${stderr}` : " Check the Codex app-server logs for the underlying import error."}`
      );
    }
    emitProgress(options.onProgress, `Claude session imported (${threadId}).`, "completed", { threadId });
    return {
      threadId,
      stderr: cleanCodexStderr(client.stderr)
    };

View on GitHub (pinned to db52e28f4d)

Solutions

1. Upgrade Codex: npm install -g @openai/codex@latest.
2. Stop any running shared broker (so a fresh app-server spawns from the new binary) then retry.
3. Confirm 'codex --version' shows a version that includes externalAgentConfig/import.
4. If a stale broker persists, clear the session dir's broker artifacts or reboot to release the socket.

Example fix

// before
await importExternalAgentSession(cwd, { sourcePath }) // throws -32601 on old codex

// after
//   npm install -g @openai/codex@latest
//   (restart the broker / new terminal)
await importExternalAgentSession(cwd, { sourcePath })

// Probe version support before importing if you can query it; otherwise rely on the catch.
// After upgrade, confirm: codex --version reports a version that supports externalAgentConfig/import.

function isMethodNotFound(error) {
  return error?.rpcCode === -32601;
}

try {
  await importExternalAgentSession(cwd, { sourcePath });
} catch (error) {
  if (error?.rpcCode === -32601 || /does not support Claude session transfer/.test(error.message)) {
    // instruct upgrade, then offer to retry after npm install -g @openai/codex@latest
  } else {
    throw error;
  }
}

When it happens

Trigger: Calling importExternalAgentSession against a Codex app-server built before the externalAgentConfig/import method shipped. The request reaches a live (but old) app-server, which returns -32601, caught in the try/catch around requestExternalAgentSessionImport.

Common situations: A pinned older @openai/codex version is installed. The broker started a previously-installed codex binary that has since been partly upgraded. A system-wide old Codex shadows the global npm install on PATH.

Related errors

• A Claude session source path is required.
• Codex reported that the Claude import completed, but did not
• Codex CLI is not installed or is missing required runtime su
• Could not identify the current Claude transcript. Retry with
• Claude session source must be a JSONL file: ${sourcePath}

AI-assisted analysis of openai/codex-plugin-cc@db52e28f4d (2026-08-13). Data as JSON: /api/errors/0a0c8aa830a37787. Report an issue: GitHub.