thedotmack/claude-mem · error

" " is required

Error message

"${key}" is required

What it means

requireString() in the recall MCP server validates tool-call arguments. If a required argument is absent, not a string, or an empty/whitespace-only string, it throws `"<key>" is required`. This gives tool callers a clear, per-key message instead of undefined behavior downstream.

Solutions

1. Include the required key in the tool-call arguments as a non-empty string (e.g. projectId: 'my-project')
2. Coerce client-side values to strings before invoking (String(projectId))
3. If 'all projects' is intended, use a tool designed for it rather than an empty projectId

Example fix

// before
await client.callTool('observations', { projectId: 42 });
// after
await client.callTool('observations', { projectId: String(42) });

function assertArgs(args: Record<string, unknown>): void {
  if (typeof args.projectId !== 'string' || args.projectId.trim().length === 0) {
    throw new Error('"projectId" is required');
  }
}

const hasProjectId = (a: Record<string, unknown>): a is Record<string, unknown> & { projectId: string } =>
  typeof a.projectId === 'string' && a.projectId.trim().length > 0;

try {
  const result = await callRecallTool('observations', args);
} catch (e) {
  if (e instanceof Error && e.message === '"projectId" is required') {
    // prompt user for a projectId or return a clear client-side error
  }
  throw e;
}

When it happens

Trigger: Calling a tool (e.g. the observations tool) without the 'projectId' argument, passing it as a non-string (number, object), or passing an empty/blank string.

Common situations: MCP client omitting arguments from the tool-call input object; sending numbers/UUIDs as non-string JSON types; test harnesses with partially filled argument maps; a client using a null projectId for 'all projects'.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• file_path is required
• Missing required argument: name
• observation_add: "content" is required
• observation_context: "query" is required
• observation_generation_status: "jobId" is required

AI-assisted analysis of thedotmack/claude-mem@d8bc9755e7 (2026-09-17). Data as JSON: /api/errors/4c51c53b66ffded8. Report an issue: GitHub.

Appendix: source

Thrown at src/server/mcp/recall-mcp-server.ts:90

      type: 'object',
      properties: {
        projectId: { type: 'string', description: 'Project to list.' },
        limit: { type: 'integer', minimum: 1, maximum: RECENT_LIMIT.max },
      },
      required: ['projectId'],
    },
  },
];

function clampLimit(raw: unknown, spec: { default: number; max: number }): number {
  if (typeof raw !== 'number' || !Number.isFinite(raw)) return spec.default;
  return Math.min(Math.max(1, Math.trunc(raw)), spec.max);
}

function requireString(args: Record<string, unknown>, key: string): string {
  const value = args[key];
  if (typeof value !== 'string' || value.trim().length === 0) {
    throw new Error(`"${key}" is required`);
  }
  return value;
}

function jsonResult(payload: unknown): CallToolResult {
  return { content: [{ type: 'text', text: JSON.stringify(payload, null, 2) }] };
}

// Dispatches a single tool call to the backend. Throws on unknown tools or
// invalid arguments; `createRecallMcpServer` converts those into MCP errors.
async function dispatchToolCall(
  backend: RecallBackend,
  name: string,
  args: Record<string, unknown>,
): Promise<CallToolResult> {
  if (name === 'search') {
    const observations = await backend.search({
      projectId: requireString(args, 'projectId'),

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