mastra-ai/mastra · warning · HTTPException

JSON.stringify(errorResponse)

Error message

JSON.stringify(errorResponse)

What it means

validateBody checks that required fields are present in a request body, accumulating per-field messages like '<key> is required'. If any are missing it throws an HTTPException 400 whose message is the JSON.stringify of the error map. The wire message therefore looks like JSON text, not a human sentence.

Source

Thrown at packages/deployer/src/server/handlers/utils.ts:13

import { HTTPException } from 'hono/http-exception';

// Validation helper
export function validateBody(body: Record<string, unknown>) {
  const errorResponse = Object.entries(body).reduce<Record<string, string>>((acc, [key, value]) => {
    if (!value) {
      acc[key] = `${key} is required`;
    }
    return acc;
  }, {});

  if (Object.keys(errorResponse).length > 0) {
    throw new HTTPException(400, { message: JSON.stringify(errorResponse) });
  }
}

View on GitHub (pinned to 75dd419e61)

Solutions

1. Parse the 400 message as JSON — each key maps to '<key> is required' — and add the missing fields to the request body.
2. Set Content-Type: application/json and send a valid JSON body.
3. Update @mastra/client-js / SDK versions so request payloads match the current server API.

Example fix

// before
curl -X POST /api/workflows/runs/restart -d '{}'
// after
curl -X POST /api/workflows/runs/restart -H 'Content-Type: application/json' -d '{"runId":"abc"}'

const required = ['runId'];
for (const key of required) {
  if (body?.[key] == null) throw new Error(`Client bug: '${key}' is required before calling this endpoint`);
}

function hasRequired<T extends object, K extends readonly (keyof T)[]>(body: object, keys: K): body is T {
  return keys.every(k => k in body && body[k] != null);
}

try {
  await client.restartRun(input);
} catch (e) {
  if (e?.status === 400) {
    const missing = JSON.parse(e.message); // { field: "field is required" }
    console.error('Missing fields:', Object.keys(missing));
  }
  throw e;
}

When it happens

Trigger: POSTing to a deployer server endpoint with a body missing required keys — e.g. omitting runId or resourceId — triggers this 400 with a JSON-encoded object of missing-field messages.

Common situations: Client SDK version mismatch after API schema changes; sending empty bodies from curl/scripts; forgetting Content-Type: application/json so fields never parse.

Related errors

• Query parameter "status" must be "draft" or "published"
• Agent ID is required
• Query parameters "versionId" and "status" are mutually exclu
• Query parameter "status" must be "draft" or "published"
• bad request: ${responseText}

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/33d9e240413e403e. Report an issue: GitHub.