serverless/serverless · error · ServerlessError

LOGS_MUTUAL_EXCLUSIVITY

LOGS_MUTUAL_EXCLUSIVITY

Error message

Cannot specify both --function and --agent. Use --function to view Lambda function logs or --agent to view agent logs.

What it means

Error "Cannot specify both --function and --agent. Use --function to view Lambda function logs or --agent to view agent logs." thrown in serverless/serverless.

Source

Thrown at packages/serverless/lib/plugins/aws/logs-agent.js:29

 * Plugin for viewing CloudWatch logs from AgentCore Runtime agents.
 * Follows the same pattern as invoke-agent.js for the invoke command.
 */
class AwsLogsAgent {
  constructor(serverless, options, pluginUtils) {
    this.serverless = serverless
    this.options = options || {}
    this.provider = this.serverless.getProvider('aws')
    this.logger = pluginUtils.log
    this.progress = pluginUtils.progress

    this.hooks = {
      'logs:logs': async () => {
        if (!this.options.agent) {
          return
        }

        if (this.options.function) {
          throw new ServerlessError(
            'Cannot specify both --function and --agent. Use --function to view Lambda function logs or --agent to view agent logs.',
            'LOGS_MUTUAL_EXCLUSIVITY',
          )
        }

        if (!this.options.tail) {
          this.progress.notice('Fetching agent logs')
        } else {
          this.logger.aside(
            `Streaming new logs for agent: "${this.options.agent}"`,
          )
          this.progress.notice('Listening')
        }

        this.validateAgent()
        this.options.interval = this.options.interval || 1000
        this.options.logGroupName = await this.resolveLogGroupName()
        const logStreamNames = await this.getLogStreams()

View on GitHub (pinned to b9d7ea51c8)

Solutions

1. Use either --function to view Lambda logs or --agent to view agent logs, but not both in the same command.

When it happens

Trigger: Thrown at packages/serverless/lib/plugins/aws/logs-agent.js:29 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of serverless/serverless@b9d7ea51c8 (2026-08-13). Data as JSON: /api/errors/59d8c56596f75c82. Report an issue: GitHub.