mastra-ai/mastra · error · Error

Target type '${targetType}' not yet supported.

Error message

Target type '${targetType}' not yet supported.

What it means

executeTarget dispatches on the experiment target's type; 'processor' targets were dropped from the roadmap and are explicitly rejected. The error is thrown synchronously before any execution happens, so no experiment items are run.

Source

Thrown at packages/core/src/datasets/experiment/executor.ts:165

          target as Agent,
          item,
          signal,
          options?.requestContext,
          options?.experimentId,
          options?.versions,
          options?.toolMocks,
          options?.unmockedToolPolicy,
        );
        break;
      case 'workflow':
        executionPromise = executeWorkflow(target as Workflow, item, options?.requestContext);
        break;
      case 'scorer':
        executionPromise = executeScorer(target as MastraScorer<any, any, any, any>, item);
        break;
      case 'processor':
        // Processor targets dropped from roadmap - not a core use case
        throw new Error(`Target type '${targetType}' not yet supported.`);
      default:
        throw new Error(`Unknown target type: ${targetType}`);
    }

    // Race execution against signal abort (ensures timeout works even if target ignores signal)
    if (signal) {
      return await raceWithSignal(executionPromise, signal);
    }

    return await executionPromise;
  } catch (error) {
    return {
      output: null,
      error: {
        message: error instanceof Error ? error.message : String(error),
        stack: error instanceof Error ? error.stack : undefined,
      },
      traceId: null,

View on GitHub (pinned to 75dd419e61)

Solutions

1. Change the target type to a supported one ('agent', 'tool', 'workflow', or 'scorer')
2. Wrap the processor logic in a tool or scorer and target that instead
3. Remove the processor experiment config and re-create it against a supported target

Example fix

// before
runExperiment({ targetType: 'processor', targetId: 'redact-pii' });
// after
runExperiment({ targetType: 'tool', targetId: 'redact-pii-tool' });

const SUPPORTED = ['agent', 'tool', 'workflow', 'scorer'] as const;
if (!SUPPORTED.includes(targetType)) {
  throw new Error(`Unsupported targetType for experiments: ${targetType}`);
}

type SupportedTargetType = 'agent' | 'tool' | 'workflow' | 'scorer';
function isSupportedTargetType(t: string): t is SupportedTargetType {
  return ['agent', 'tool', 'workflow', 'scorer'].includes(t);
}

try {
  await runExperiment(config);
} catch (err) {
  if (err instanceof Error && err.message.includes("not yet supported")) {
    // replace processor target with a tool/scorer equivalent
  } else throw err;
}

When it happens

Trigger: Configuring an experiment with targetType 'processor' (e.g. runExperiment({ targetType: 'processor', targetId: ... }) or a stored target referencing a processor).

Common situations: Copying an experiment config from an older codebase/docs where processor targets were supported; migrating experiments after the roadmap change and leaving the old target type in place.

Related errors

• Unknown target type: ${targetType}
• No data source: provide datasetId or data
• Target not found: ${targetType}/${targetId}
• No task: provide targetType+targetId or task
• Async buffering is not yet supported with scope: 'resource'.

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/95e7007b539a4d4b. Report an issue: GitHub.