Invalid MemoryRequestContext.resourceId: expected string, go

Error message

Invalid MemoryRequestContext.resourceId: expected string, got ${typeof ctx.resourceId}

What it means

parseMemoryRequestContext validates the 'MastraMemory' RequestContext entry; this error is thrown when `resourceId` is present but is not a string. The resourceId identifies the user/owner for memory scoping, so the library enforces a string to keep resource-scoped memory lookups deterministic.

Source

Thrown at packages/core/src/memory/types.ts:169

    throw new Error(`Invalid MemoryRequestContext: expected object, got ${typeof memoryContext}`);
  }

  const ctx = memoryContext as Record<string, unknown>;

  // Validate thread if present
  if (ctx.thread !== undefined) {
    if (typeof ctx.thread !== 'object' || ctx.thread === null) {
      throw new Error(`Invalid MemoryRequestContext.thread: expected object, got ${typeof ctx.thread}`);
    }
    const thread = ctx.thread as Record<string, unknown>;
    if (typeof thread.id !== 'string') {
      throw new Error(`Invalid MemoryRequestContext.thread.id: expected string, got ${typeof thread.id}`);
    }
  }

  // Validate resourceId if present
  if (ctx.resourceId !== undefined && typeof ctx.resourceId !== 'string') {
    throw new Error(`Invalid MemoryRequestContext.resourceId: expected string, got ${typeof ctx.resourceId}`);
  }

  return memoryContext as MemoryRequestContext;
}

export type MessageResponse<T extends 'raw' | 'core_message'> = {
  raw: MastraMessageV1[];
  core_message: CoreMessage[];
}[T];

type BaseWorkingMemory = {
  enabled: boolean;
  /**
   * Scope for working memory storage.
   * - 'resource': Memory persists across all threads for the same resource/user (default)
   * - 'thread': Memory is isolated per conversation thread
   *
   * @default 'resource'

View on GitHub (pinned to 75dd419e61)

Solutions

Set `resourceId` to a plain string in the 'MastraMemory' RequestContext entry: `resourceId: 'user-123'`.
Coerce at construction time: `resourceId: String(user.id)`.
If the resource is unknown, omit the key entirely instead of passing null/objects.
Validate the context shape with parseMemoryRequestContext in your own request setup to catch the mistake at the boundary.

Example fix

// before
requestContext.set('MastraMemory', { thread: { id: 't1' }, resourceId: user.id }); // number
// after
requestContext.set('MastraMemory', { thread: { id: 't1' }, resourceId: String(user.id) });

Defensive patterns

Strategy: validation

Validate before calling

const ctx = requestContext?.get('MastraMemory');
if (ctx && ctx.resourceId !== undefined && typeof ctx.resourceId !== 'string') {
  throw new TypeError(`resourceId must be a string, got ${typeof ctx.resourceId}`);
}

Type guard

function hasStringResourceId(ctx: unknown): ctx is { resourceId: string } {
  return typeof ctx === 'object' && ctx !== null &&
    'resourceId' in ctx && typeof (ctx as any).resourceId === 'string';
}

Try / catch

try {
  const memCtx = parseMemoryRequestContext(requestContext);
  // use memCtx.resourceId
} catch (err) {
  if (err instanceof Error && err.message.includes('resourceId')) {
    logger.error('Malformed memory context: resourceId is not a string', { err });
    requestContext.set('MastraMemory', undefined); // or rebuild context correctly
    return;
  }
  throw err;
}

Prevention

Coerce user ids to strings once where they enter your app (String(user.id)).
Keep resourceId and threadId as plain strings in shared context-building utilities.
Add a unit test asserting the shape of the 'MastraMemory' RequestContext entry you build.
Omit resourceId rather than passing null/objects when unknown.

When it happens

Trigger: Any call routed through parseMemoryRequestContext (memoryContext, threadId, memoryRunState, getThreadId, resolveThreadId, memoryConfig) where the 'MastraMemory' context has `resourceId` defined as a non-string — e.g. `resourceId: 12345`, `resourceId: { id: 'u1' }`, or a deserialized object/number.

Common situations: Passing a numeric user id from your database directly as resourceId; passing a user object instead of its id; JSON round-tripping that converted the id; mixing up the resourceId/threadId fields in a hand-built context.

Related errors

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/1ad4be7e4a3c4980. Report an issue: GitHub.