Knowledge storage domain is not available on ${this.storage.

Error message

Knowledge storage domain is not available on ${this.storage.constructor.name}

What it means

Memory resolves its knowledge domain through `this.storage.getStore('knowledge')`. If the configured storage adapter does not implement/support the 'knowledge' domain, getStore returns undefined and Memory throws this error naming the storage class. It means the chosen storage backend cannot host knowledge data required by subconscious/semantic-index features.

Source

Thrown at packages/memory/src/index.ts:527

        throw new Error(
          '`retrieval: { vector: true }` requires an embedder. Pass an `embedder` option to your Memory instance.',
        );
      }
    }
    if (omConfig?.experimental_subconscious) {
      if (!this.vector) {
        throw new Error('Subconscious semantic knowledge requires a vector store. Pass a `vector` option to Memory.');
      }
      if (!this.embedder) {
        throw new Error('Subconscious semantic knowledge requires an embedder. Pass an `embedder` option to Memory.');
      }
    }
  }

  private async getKnowledgeStore(): Promise<KnowledgeStorage> {
    const store = await this.storage.getStore('knowledge');
    if (!store) {
      throw new Error(`Knowledge storage domain is not available on ${this.storage.constructor.name}`);
    }
    return store;
  }

  public async getKnowledgeSemanticIndex(): Promise<KnowledgeSemanticIndexCoordinator> {
    if (!this.vector || !this.embedder) {
      throw new Error('Subconscious semantic knowledge requires both a vector store and an embedder.');
    }
    this._knowledgeSemanticIndex ??= this.getKnowledgeStore().then(
      knowledge =>
        new KnowledgeSemanticIndexCoordinator({
          knowledge,
          vector: this.vector!,
          embedder: this.embedder!,
          embedderOptions: this.embedderOptions,
        }),
    );
    return this._knowledgeSemanticIndex;

View on GitHub (pinned to 75dd419e61)

Solutions

Use a storage adapter that supports the knowledge domain (e.g. LibSQLStorage/PostgresStorage current versions)
Upgrade the storage package so the knowledge domain is implemented
If using a custom adapter, implement getStore to return a KnowledgeStorage for the 'knowledge' domain
Check for initialization errors in the storage adapter that may prevent domain registration

Example fix

// before
new Memory({ storage: new MyMinimalStorage(), ... })
// after
new Memory({ storage: new LibSQLStorage({ url: process.env.DB_URL }), ... })

Defensive patterns

Strategy: validation

Validate before calling

const knowledgeStore = await storage.getStore('knowledge');
if (!knowledgeStore) {
  throw new Error(`${storage.constructor.name} does not support the knowledge domain; use a compatible adapter`);
}

Try / catch

try {
  const idx = await memory.getKnowledgeSemanticIndex();
} catch (err) {
  if (err instanceof Error && err.message.includes('Knowledge storage domain is not available')) {
    // switch to a storage adapter that implements the knowledge domain
  } else throw err;
}

Prevention

Verify adapter feature matrix (knowledge domain support) before adopting a storage backend
Upgrade storage packages to versions implementing getStore('knowledge')
Smoke-test knowledge features against the target storage in CI
Implement the knowledge domain if writing a custom storage adapter

When it happens

Trigger: Calling getKnowledgeSemanticIndex or _initOMEngine (which call getKnowledgeStore) on a Memory whose storage adapter lacks a 'knowledge' store — e.g. a minimal/custom storage implementation or an adapter that doesn't support the knowledge domain.

Common situations: Using a custom or third-party Storage adapter that hasn't implemented getStore('knowledge'); using a storage backend that predates the knowledge domain; misconfigured storage that fails to register its domains.

Related errors

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/7c989e5e641002e4. Report an issue: GitHub.