catalyst-functions

name	catalyst-functions
description	Catalyst serverless functions — all 7 types (Basic I/O, Advanced I/O, Event, Cron, Job, Integration, Browser Logic), handler signatures, catalyst-config.json, Security Rules, API Gateway routing, file uploads, busboy, Express middleware, environment variables, function URL, and function testing. Requires MCP connection — check for CatalystbyZoho_* tools before any operation. Trigger on 'write a function', 'catalyst function', 'API Gateway', 'Security Rules', 'function not found', 'function returns 401', 'busboy', 'middleware', 'function URL', 'environment variable in function', 'duplicate CORS headers', 'CORS error in browser', 'Access-Control-Allow-Origin multiple values', 'function URL 404', 'execute suffix', 'function timeout', 'function hangs', or any function type question. Do NOT use for persistent servers, long-running processes, or Docker deployments — use catalyst-appsail instead.
compatibility	Requires Catalyst CLI (`npm install -g zcatalyst-cli`) and Node.js v20 (recommended; v14–v18 also supported). Java functions also require JDK 8, 11, or 17. Python functions require Python 3.9.
metadata	{"version":"2.0.1"}

How It Works

1. Verify local scaffold — both catalyst init and functions:add support non-interactive mode (CLI v1.27.0+). Check whether .catalystrc and catalyst.json exist. If missing, use MCP tools to get the org ID and project ID, then run:

   catalyst init --org <orgId> -p <projectId> -ni
   

   Never ask the user to run catalyst init interactively. NI mode can only link an existing project — if none exists, tell the user to create one in the console first. Once initialized, add functions non-interactively:

   catalyst functions:add --name <name> --type <type> --stack <stack> -ni
   # e.g. catalyst functions:add --name api --type aio --stack node20 -ni
   

2. Identify the function type — Basic I/O for simple request/response, Advanced I/O for raw HTTP control, Event for trigger-based, Cron/Job for scheduled, Integration for Zoho service events, Browser Logic for Puppeteer.

3. Load references/functions-basics.md — for the matching handler signature, catalyst-config.json keys, SDK init pattern, and CORS setup.

4. Load references/functions-advanced.md — for file uploads (busboy), streaming responses, error handling, or chaining functions.

5. Load references/api-gateway.md — for routing rules, rate limiting, or gateway-level CORS.

6. Validate config — Confirm catalyst-config.json uses deployment + execution keys only. Never use function or entry_point.

Security Checklist

• Functions are publicly accessible by default. Security Rules sets authentication to optional when a function is created — its URL is globally accessible to everyone with no restrictions. Set "authentication": "required" in the Security Rules JSON for any function that reads or writes user data or sensitive resources.
• API Gateway replaces Security Rules — do not use both. Enabling API Gateway automatically disables Security Rules. Pick one auth/routing layer per function.

Triggers

Use this skill for: "write a function", "catalyst function", "Basic I/O", "Advanced I/O", "Event function", "Cron function", "Browser Logic", catalyst-config.json, "function handler", "API Gateway", "rate limiting", "busboy", "file upload in function", catalyst deploy --only functions:<function-name>, catalyst functions:add, "function CORS", or any function type or function configuration question.

Deployment command note:

• Use catalyst deploy --only functions:<function-name> to deploy one function (where functions:<name> targets the function by its folder name).
• Use catalyst deploy --only functions to deploy all functions at once.

References

Reference	Load when the query is about…
references/functions-basics.md	Start here for any function question. Function type selection, Basic I/O and Advanced I/O handler signatures, catalyst-config.json, user-scope vs admin-scope, CORS, Security Rules, execution limits
references/functions-advanced.md	Advanced I/O patterns only. Express vs raw-http template differences, file uploads (busboy), streaming files from Stratus, error handling patterns, CORS for local dev, local testing, function chaining, ZCQL result unwrapping, HTTP payload limits
references/functions-templates.md	Event, Cron, Job, or Integration functions. Handler templates for all background/scheduled types, SDK component reference, retry behavior, cold start data, and the full common errors table
references/api-gateway.md	API Gateway config only. Enable/disable gateway, routing rules, rate limiting, CORS via gateway