[BUG] Environment variables in MCP Servers configuration seems to not be passed/used correctly

[matteo-ladrat-Legrand]

Context

I'm trying to put in place a script that will start an agent using the SDK with the Azure DevOps MCP server. For authentication, I need to use the environment variable as specified in the documentation ADO_MCP_AUTH_TOKEN however it seems that passing the environment variables in the MCP server configuration doesn't work at all ...

Code

import { CopilotClient } from '@github/copilot-sdk'
import process from 'node:process'

async function main() {
    const client = new CopilotClient({
        autoStart: true,
        autoRestart: false,
        logLevel: 'all',
        githubToken: process.env.GITHUB_TOKEN,
        useStdio: true,
    })

    const env = {
        ADO_MCP_AUTH_TOKEN: process.env.SYSTEM_ACCESSTOKEN
    }

    const session = await client.createSession({
        model: 'gpt-4.1',
        mcpServers: {
            devops: {
                type: 'stdio',
                command: 'npx',
                args: [
                    '-y',
                    '@azure-devops/mcp', process.env.ADO_ORG,
                    '-d', 'core', 'work', 'work-items',
                    '--authentication', 'envvar'
                ],
                env,
                tools: ['*']
            }
        }
    })

    session.on(event => console.dir(event, { depth: 6 }))

    const response = await session.sendAndWait({
        prompt: `In the project "${process.env.ADO_PROJECT}", what does the work item with ID "30026" look like?`
    })
    if (!response) {
        throw new Error('No response received from Copilot')
    }

    console.log('==== Response from Copilot ====')
    console.dir(response, { depth: 6 })
    console.log('==== Response from Copilot ====')

    await session.destroy()
    await client.stop()
}

main()

[github-actions]

Thank you for reporting this issue, @matteo-ladrat-Legrand!

I've labeled this as bug and sdk/nodejs since it involves the Node.js SDK and MCP server environment variable handling.

This appears to be related to issue #163, which reports similar problems with environment variables not being passed to MCP servers (in that case for Python SDK). The issue seems to affect multiple SDK implementations.

Your reproduction code is very helpful. A maintainer will investigate the root cause of why the env property in the MCP server configuration isn't working as expected.

AI generated by Issue Triage Agent

[matteo-ladrat-Legrand]

I found a workaround to load environment variables :

const env = {
    ADO_MCP_AUTH_TOKEN: '${SYSTEM_ACCESSTOKEN}'
}

However, I think the initial code should be working based on documentation ....