using-lambda-connector

name	using-lambda-connector
description	Implements AWS Lambda function invocation and management using generated clients and MCP tools. Use when doing ANYTHING that touches Lambda or AWS Lambda in any way, load this skill.

Major Platform Resource: AWS Lambda

Common: Interacting with Resources

Security: Never connect directly to databases/APIs. Never use credentials in code. Always use generated clients or MCP tools.

Two ways to interact with resources:

1. MCP tools (direct, no code needed): Tools follow the pattern mcp__resources__<resourcetype>_<toolname>. Use mcp__resources__list_resources to discover available resources and their IDs.
2. Generated TypeScript clients (for app code): Call mcp__resource-tools__add-resource-client with a resourceId to generate a typed client. Clients are created in /clients/ (Next.js) or /src/clients/ (Vite).

CRITICAL: Do NOT guess client method names or signatures. The TypeScript clients in @major-tech/resource-client have strongly typed inputs and outputs. ALWAYS read the actual client source code in the generated /clients/ directory (or the package itself) to verify available methods and their exact signatures before writing any client code.

Framework note: Next.js = resource clients must be used in server-side code only (Server Components, Server Actions, API Routes). Vite = call directly from frontend.

Error handling: Always check result.ok before accessing result.result.

Invocation keys must be static strings — use descriptive literals like "fetch-user-orders", never dynamic values like `${date}-records`.

---

MCP Tools

• mcp__resources__lambda_list_functions — List accessible Lambda functions. Args: resourceId, maxItems?
• mcp__resources__lambda_get_function — Get function config and code location. Args: resourceId, functionName, qualifier?
• mcp__resources__lambda_invoke — Invoke a function. Args: resourceId, functionName, payload?, invocationType?, qualifier?

TypeScript Client

import { lambdaClient } from "./clients";

// invoke(functionName, payload, invocationKey, options?)
const result = await lambdaClient.invoke("my-function", { userId: "123", action: "process" }, "invoke-processor", {
	invocationType: "RequestResponse",
});
if (result.ok) {
	console.log(result.result);
}

Tips

• Invocation types: RequestResponse (synchronous, default), Event (async fire-and-forget), DryRun (validate without executing)
• Payload size limit: 6MB for synchronous, 256KB for async invocations
• Use qualifier to invoke a specific version or alias (defaults to $LATEST)

Docs: AWS Lambda Documentation