TencentCloud/TencentDB-Agent-Memory · error

File not found: ${key}

Error message

File not found: ${key}

What it means

readFileOrThrow is the strict variant of readFile: readFile returns null for a missing object, while readFileOrThrow converts that null into a thrown Error with the key in the message. It exists so callers that require the file can avoid null-check boilerplate.

Source

Thrown at MemoryCore/src/core/storage/adapter.ts:99

  return new StorageAdapter(new ScopedStorageBackend(base.getBackend(), prefix));
}

export class StorageAdapter {
  constructor(private backend: IStorageBackend) {}

  get type() { return this.backend.type; }

  // ── fs.readFile replacement ──

  async readFile(key: string): Promise<string | null> {
    const obj = await this.backend.getObject(key);
    if (!obj) return null;
    return obj.content.toString("utf-8");
  }

  async readFileOrThrow(key: string): Promise<string> {
    const content = await this.readFile(key);
    if (content === null) throw new Error(`File not found: ${key}`);
    return content;
  }

  async readFileBuffer(key: string): Promise<Buffer | null> {
    const obj = await this.backend.getObject(key);
    if (!obj) return null;
    return obj.content;
  }

  // ── fs.writeFile replacement ──

  async writeFile(key: string, content: string | Buffer): Promise<void> {
    return this.backend.putObject(key, content);
  }

  // ── fs.appendFile replacement — atomic via backend.appendObject (CR-1 fix) ──

  /**

View on GitHub (pinned to 3efcd317b8)

Solutions

1. Check existence first with adapter.exists(key) or use readFile and handle null
2. Fix the key — verify exact spelling/case and that it is relative to the adapter's scope
3. Create/initialize the object (write a default) on first access if absence is expected
4. Handle the error and fall back to a default value in the caller

Example fix

// before
const cfg = await adapter.readFileOrThrow('config.json');
// after
const cfg = (await adapter.readFile('config.json')) ?? JSON.stringify(DEFAULT_CONFIG);

if (!(await adapter.exists(key))) {
  return DEFAULT_CONTENT; // or throw a domain-level NotFound
}

try {
  content = await adapter.readFileOrThrow(key);
} catch (e) {
  if (String(e.message).startsWith('File not found:')) {
    content = await initializeDefault(key); // create default on first access
  } else throw e;
}

When it happens

Trigger: Calling readFileOrThrow(key) when no object exists at that (already prefixed) key in the storage backend.

Common situations: Reading a config or state file before it was ever written; a typo or case mismatch in the key; the object was deleted by another process; using the raw key without the adapter's scoping prefix on a raw backend.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• Source not found: ${sourceKey}
• STORAGE_NOT_FOUND
• Generation log object key exceeds COS limit
• Invalid generation log key
• Invalid generation log cursor

AI-assisted analysis of TencentCloud/TencentDB-Agent-Memory@3efcd317b8 (2026-09-01). Data as JSON: /api/errors/89f8494318308a85. Report an issue: GitHub.