mastra-ai/mastra · error · Error

Multiple suspended steps found: ${pathStrings.join(', ')}. P

Error message

Multiple suspended steps found: ${pathStrings.join(', ')}. Please specify which step to resume using the "step" parameter.

What it means

When resuming an evented workflow without an explicit "step" parameter, Mastra looks up the snapshot's suspendedPaths. If exactly one step is suspended it auto-selects it; if more than one is suspended it cannot disambiguate, so it throws listing all suspended step paths and asks the caller to pass "step". This prevents resuming the wrong branch of the workflow.

Source

Thrown at packages/core/src/workflows/evented/workflow.ts:2394

              suspendedStepPaths.push([stepId, ...nestedPath]);
            } else {
              // For single-level suspension, just use the step ID
              suspendedStepPaths.push([stepId]);
            }
          }
        }
      });

      if (suspendedStepPaths.length === 0) {
        throw new Error('No suspended steps found in this workflow run');
      }

      if (suspendedStepPaths.length === 1) {
        // For single suspended step, use the full path
        steps = suspendedStepPaths[0]!;
      } else {
        const pathStrings = suspendedStepPaths.map(path => `[${path.join(', ')}]`);
        throw new Error(
          `Multiple suspended steps found: ${pathStrings.join(', ')}. ` +
            'Please specify which step to resume using the "step" parameter.',
        );
      }
    }

    // Validate that the step is actually suspended
    const suspendedStepIds = Object.keys(snapshot?.suspendedPaths ?? {});
    const isStepSuspended = suspendedStepIds.includes(steps?.[0] ?? '');

    if (!isStepSuspended) {
      throw new Error(
        `This workflow step "${steps?.[0]}" was not suspended. Available suspended steps: [${suspendedStepIds.join(', ')}]`,
      );
    }

    const resumePath = snapshot.suspendedPaths?.[steps[0]!] as any;
    // Start with the snapshot's request context (old values)

View on GitHub (pinned to 75dd419e61)

Solutions

1. Pass the step to resume: workflow.resume({ runId, resumeData, step: [stepId] }) (nested steps use the full path array, e.g. step: ['parent', 'child']).
2. Inspect snapshot.suspendedPaths (via getWorkflowRunState / the error message) to see which paths are suspended and pick the intended one.
3. If you want auto-resume to work, ensure only one step is suspended per resume (resume sequentially, one branch at a time).

Example fix

// before
await workflow.resume({ runId, resumeData: { approved: true } });
// after
await workflow.resume({ runId, resumeData: { approved: true }, step: ['humanApproval'] });

const snap = await workflow.getWorkflowRunState(runId);
const suspended = Object.keys(snap?.suspendedPaths ?? {});
if (suspended.length > 1) {
  throw new Error(`Ambiguous resume: pick one of ${suspended.join(', ')}`);
}
await workflow.resume({ runId, resumeData, step: [suspended[0]!] });

try {
  await workflow.resume({ runId, resumeData });
} catch (err) {
  if (err instanceof Error && err.message.startsWith('Multiple suspended steps found')) {
    const steps = err.message.match(/\[(.*?)\]/g)?.map(s => s.slice(1, -1));
    await workflow.resume({ runId, resumeData, step: JSON.parse(`[${steps?.[0]}]`) });
  } else throw err;
}

When it happens

Trigger: Calling workflow.resume({ runId, resumeData }) (or resume with no step) on a run whose snapshot.suspendedPaths contains two or more entries, e.g. after parallel/branch steps both suspended with .suspend().

Common situations: Workflows using parallel() or conditionally-exclusive branches where two or more steps call suspend(); developers added a second suspend point after initial testing with only one suspended step; fan-out patterns resuming without a step selector.

Related errors

• This workflow step "${steps?.[0]}" was not suspended. Availa
• AGENT_RESUME_NO_SNAPSHOT_FOUND
• AGENT_RESUME_TOOL_CALL_NOT_SUSPENDED
• Cannot resume workflow: workflows store is required
• Cannot resume workflow: no snapshot found for runId ${this.r

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/5857ebe0a19bfaf0. Report an issue: GitHub.