ERR_MODULE_NOT_FOUND in 0.1.31: session.js missing .js extension on vscode-jsonrpc/node import

[paulwhitten]

Bug

@github/copilot-sdk@0.1.31 crashes on startup under Node.js v24 due to a missing .js file extension on a new import added to dist/session.js.

Same class of defect as #8 (fixed in 0.1.10/0.1.11 for client.js).

Error

Error [ERR_MODULE_NOT_FOUND]: Cannot find module
  '.../node_modules/vscode-jsonrpc/node'
  imported from .../node_modules/@github/copilot-sdk/dist/session.js
Did you mean to import "vscode-jsonrpc/node.js"?

Root Cause

SDK 0.1.31 added a new import to dist/session.js (not present in 0.1.29) that omits the .js extension:

# 0.1.31 session.js line 1 -- NEW import, missing .js
import { ConnectionError, ResponseError } from "vscode-jsonrpc/node";

# 0.1.31 client.js line 10 -- existing import, correct
} from "vscode-jsonrpc/node.js";

The SDK declares "type": "module" (ESM). The dependency vscode-jsonrpc@8.2.1 has no exports map and no "type" field. Without an exports map, Node ESM resolution does not auto-append .js for subpath imports, so "vscode-jsonrpc/node" fails to resolve even though node.js exists in the package root.

dist/client.js already uses the correct "vscode-jsonrpc/node.js" form -- the new session.js import simply did not follow the same convention.

Diff: 0.1.29 / 0.1.30 vs 0.1.31

File	0.1.29	0.1.30	0.1.31
dist/session.js	No vscode-jsonrpc import	No vscode-jsonrpc import	import { ConnectionError, ResponseError } from "vscode-jsonrpc/node" (missing .js)
dist/client.js	from "vscode-jsonrpc/node.js"	from "vscode-jsonrpc/node.js"	from "vscode-jsonrpc/node.js" (unchanged, correct)

Environment

• Affected: 0.1.31
• Working: 0.1.29, 0.1.30
• Node.js: v24.14.0
• OS: Linux

Workaround

Pin to 0.1.30 (or 0.1.29):

"@github/copilot-sdk": "0.1.30"

Suggested Fix

Add .js to the import in the source that produces dist/session.js:

import { ConnectionError, ResponseError } from "vscode-jsonrpc/node.js";

[theblixguy]

I also ran into this in our test suite (vitest with Node ESM). There's another workaround which involves registering a custom module resolution hook before the SDK gets imported:

// filename: fix-jsonrpc-import.js

import { register } from "node:module";

register(
  "data:text/javascript," +
    encodeURIComponent(`
      export function resolve(specifier, context, nextResolve) {
        if (specifier === "vscode-jsonrpc/node") {
          return nextResolve("vscode-jsonrpc/node.js", context);
        }
        return nextResolve(specifier, context);
      }
    `),
  import.meta.url,
);

For vitest, you can drop this in a file and add it to the setupFiles in your config. For plain Node, you can pass it with --import ./fix-jsonrpc-import.js. The hook will intercept the bare vscode-jsonrpc/node specifier and appends .js before Node's default resolver sees it.

It's worth noting that this only affects ESM contexts where Node enforces strict specifier resolution. CJS works fine and so do bundlers like tsx, since they handle extension-less imports on their own.

[Rubiss]

Still present in v0.1.32, also reproducible on Node 22

Confirming this bug is not fixed in v0.1.32 (latest as of 2026-03-14). The bad import is unchanged in the published package:

$ npm show @github/copilot-sdk version
0.1.32

$ node -e "require('fs').readFileSync(require.resolve('@github/copilot-sdk/dist/session.js'), 'utf8').split('\n').slice(0,1).forEach(l => console.log(l))"
import { ConnectionError, ResponseError } from "vscode-jsonrpc/node";

Additional environment data

Field	Value
@github/copilot-sdk	0.1.32
vscode-jsonrpc	8.2.1
Node.js	v22.22.0 (also fails on v22, not just v24)
OS	Linux (WSL2)

The error is identical to what #707 describes — Node 22's strict ESM resolver also refuses to auto-append .js for subpath imports on packages without an exports map.

Workaround for npm-installed packages

As an alternative to the module hook in the previous comment, a postinstall script can patch the file in place (no runtime overhead):

// postinstall patch (CJS, no deps required)
const fs = require('fs'), path = require('path');
const f = path.resolve(process.cwd(), 'node_modules/@github/copilot-sdk/dist/session.js');
try {
  const s = fs.readFileSync(f, 'utf8');
  fs.writeFileSync(f, s.replace('from "vscode-jsonrpc/node"', 'from "vscode-jsonrpc/node.js"'));
} catch (_) {}

This is idempotent and non-fatal if the file is absent. Hoping for an official fix in 0.1.33+.

[norrisp90]

Confirming on Node 22 with @github/copilot-sdk@0.1.32 + vscode-jsonrpc@8.2.1 in a CommonJS Express server that dynamic-imports the SDK.

We settled on patch-package as the workaround — it's the lightest touch and works cleanly in Docker builds:

// package.json
{
  "scripts": { "postinstall": "npx patch-package" },
  "devDependencies": { "patch-package": "^8.0.0" }
}

# patches/@github+copilot-sdk+0.1.32.patch
--- a/node_modules/@github/copilot-sdk/dist/session.js
+++ b/node_modules/@github/copilot-sdk/dist/session.js
@@ -1,4 +1,4 @@
-import { ConnectionError, ResponseError } from "vscode-jsonrpc/node";
+import { ConnectionError, ResponseError } from "vscode-jsonrpc/node.js";
 import { createSessionRpc } from "./generated/rpc.js";

No runtime hooks, no version overrides, auto-applies on npm install, and self-removes when the SDK ships the fix.

[theblixguy]

It's fixed on main but I think they haven't shipped a new release since then, so we need to wait for .33

[sinedied]

Bumping this, the issue is already fixed so would it be possible to publish a new version? This is currently blocking

[patniko]

Coming. We are combining a few breaking changes and releases for integrators at the moment. Expect a rev to 0.2.xx within the next day.

[SteveSandersonMS]

@sinedied Just shipped 0.1.33-preview.3 to NPM - please let us know if you still run into this issue.

[sinedied]

@SteveSandersonMS updated, tested it fixed the issue thanks!