Cloud Functions Development

Use this skill when developing, deploying, and managing CloudBase cloud functions (Node.js serverless functions).

When to use this skill

Use this skill for cloud function operations when you need to:

• Create and deploy Node.js cloud functions
• Understand runtime limitations and selection
• Query function logs and monitor execution
• Invoke cloud functions from applications
• Configure HTTP access for cloud functions

Do NOT use for:

• CloudRun backend services (use

  cloudrun-development

  skill)
• Multi-language backend services (use

  cloudrun-development

  skill)
• Database operations (use database skills)

How to use this skill (for a coding agent)

1. Understand runtime limitations

   • Runtime CANNOT be changed after function creation
   • Must select correct runtime during initial creation
   • If runtime needs to change, must delete and recreate function

2. Choose the right runtime

   • Check supported runtimes list below
   • Default:

     Nodejs18.15

     (recommended)
   • Consider Node.js version compatibility with dependencies

3. Deploy functions correctly

   • Use

     createFunction

     for new functions
   • Use

     updateFunctionCode

     for code updates (runtime cannot be changed)
   • Provide correct

     functionRootPath

     (parent directory of function folder)

4. Query logs properly

   • Use

     getFunctionLogs

     for log list (basic info)
   • Use

     getFunctionLogDetail

     with RequestId for detailed logs
   • Note time range limitations (max 1 day interval)

---

Core Knowledge

Runtime Environment

⚠️ CRITICAL: Runtime cannot be modified after function creation

Once a cloud function is created with a specific runtime, the runtime cannot be changed. If you need a different runtime:

1. Delete the existing function
2. Create a new function with the desired runtime

Supported Node.js Runtimes:

• Nodejs18.15

  (Default, Recommended)

• Nodejs16.13

• Nodejs14.18

• Nodejs12.16

• Nodejs10.15

• Nodejs8.9

Runtime Selection Guidelines:

• Use

  Nodejs18.15

  for new projects (default, most modern)
• Choose older versions only if dependencies require specific Node.js versions
• Consider security updates and support lifecycle
• Test thoroughly with selected runtime before deployment

Function Structure

Cloud functions require:

1. Function Directory: Contains function code

   • Must have

     index.js

     (or specified entry file)
   • Must export handler:

     exports.main = async (event, context) => {}

   • Include

     package.json

     with dependencies

2. Function Root Path: Parent directory containing function directories

   • Example: If function is at

     /project/cloudfunctions/myFunction/

   • functionRootPath

     should be

     /project/cloudfunctions/

   • Important: Do NOT include function name in root path

3. Entry Point: Default is

   index.js

   with

   exports.main

   • Can be customized via

     handler

     parameter

Function Deployment

Creating New Functions:

Use

createFunction

tool (see MCP tool documentation for full parameter list):

• Important: Always specify

  func.runtime

  explicitly (defaults to

  Nodejs18.15

  )
• Provide

  functionRootPath

  as parent directory of function folders (absolute path)
• Use

  force=true

  to overwrite existing function

Updating Function Code:

Use

updateFunctionCode

tool:

• ⚠️ Note: Only updates code, cannot change runtime
• If runtime needs to change, delete and recreate function

Deployment Best Practices:

1. Always specify runtime explicitly when creating functions
2. Use absolute paths for

   functionRootPath

3. Don't upload node_modules - dependencies installed automatically
4. Test locally before deployment when possible
5. Use environment variables for configuration, not hardcoded values

Function Logs

Querying Logs:

Primary Method: Use

getFunctionLogs

and

getFunctionLogDetail

tools (see MCP tool documentation).

Alternative Method (Plan B): If tools unavailable, use

callCloudApi

:

1. Get Log List - Use

   GetFunctionLogs

   action:

callCloudApi({
  service: "tcb",
  action: "GetFunctionLogs",
  params: {
    EnvId: "{envId}",
    FunctionName: "functionName",
    Offset: 0,
    Limit: 10,
    StartTime: "2024-01-01 00:00:00",
    EndTime: "2024-01-01 23:59:59",
    LogRequestId: "optional-request-id",
    Qualifier: "$LATEST"
  }
})

2. Get Log Details - Use

   GetFunctionLogDetail

   action (requires LogRequestId from step 1):

callCloudApi({
  service: "tcb",
  action: "GetFunctionLogDetail",
  params: {
    StartTime: "2024-01-01 00:00:00",
    EndTime: "2024-01-01 23:59:59",
    LogRequestId: "request-id-from-log-list"
  }
})

Log Query Limitations:

• Offset + Limit

  cannot exceed 10000

• StartTime

  and

  EndTime

  interval cannot exceed 1 day
• Use pagination for large time ranges

Log Query Best Practices:

1. Query logs within 1-day windows
2. Use RequestId for specific invocation debugging
3. Combine list and detail queries for comprehensive debugging
4. Check logs after deployment to verify function behavior

Invoking Cloud Functions

From Web Applications:

import cloudbase from "@cloudbase/js-sdk";

import cloudbaseSDK from "@cloudbase/js-sdk";

const cloudbase = cloudbaseSDK.init({
  env: 'your-env-id',
  region: 'ap-shanghai',
  accessKey: 'your-access-key'
});

// Call cloud function
const result = await cloudbase.callFunction({
  name: "functionName",
  data: { /* function parameters */ }
});

From Mini Programs:

wx.cloud.callFunction({
  name: "functionName",
  data: { /* function parameters */ }
}).then(res => {
  console.log(res.result);
});

From Node.js Backend:

const cloudbase = require("@cloudbase/node-sdk");

const app = cloudbase.init({
  env: "your-env-id"
});

const result = await app.callFunction({
  name: "functionName",
  data: { /* function parameters */ }
});

From HTTP API:

Use CloudBase HTTP API to invoke functions:

• Endpoint:

  https://api.cloudbase.net/v1/{envId}/functions/{functionName}/invoke

• Requires authentication token
• See

  http-api

  skill for details

HTTP Access Configuration

HTTP Access vs HTTP API:

• HTTP API: Uses CloudBase API endpoint (

  https://api.cloudbase.net/v1/{envId}/functions/{functionName}/invoke

  ) with authentication token
• HTTP Access: Creates direct HTTP/HTTPS endpoint for standard REST API access (GET, POST, etc.) without SDK or CloudBase API format

Creating HTTP Access:

Primary Method: Use

createFunctionHTTPAccess

tool (see MCP tool documentation).

Alternative Method (Plan B): If tool unavailable, use

callCloudApi

with

CreateCloudBaseGWAPI

:

callCloudApi({
  service: "tcb",
  action: "CreateCloudBaseGWAPI",
  params: {
    EnableUnion: true,
    Path: "/api/users",
    ServiceId: "{envId}",
    Type: 6,
    Name: "functionName",
    AuthSwitch: 2,
    PathTransmission: 2,
    EnableRegion: true,
    Domain: "*"  // Use "*" for default domain, or custom domain name
  }
})

Key Parameters:

• Type: 6

  - Cloud Function type (required)

• AuthSwitch: 2

  - No auth (1 = with auth)

• Domain: "*"

  - Default domain, or specify custom domain

Access URL:

https://{envId}.{region}.app.tcloudbase.com/{path}

or

https://{domain}/{path}

Function Configuration

Environment Variables:

Set via

func.envVariables

when creating/updating:

{
  envVariables: {
    "DATABASE_URL": "mysql://...",
    "API_KEY": "secret-key"
  }
}

⚠️ CRITICAL: Environment Variable Update Constraint

When updating environment variables for existing functions:

1. MUST first query current environment variables using

   getFunctionList

   with

   action=detail

   to get the function's current configuration
2. MUST merge new environment variables with existing ones
3. DO NOT directly overwrite - this will delete existing environment variables not included in the update

Correct Update Pattern:

// 1. First, get current function details
const currentFunction = await getFunctionList({
  action: "detail",
  name: "functionName"
});

// 2. Merge existing envVariables with new ones
const mergedEnvVariables = {
  ...currentFunction.EnvVariables,  // Existing variables
  ...newEnvVariables                 // New/updated variables
};

// 3. Update with merged variables
await updateFunctionConfig({
  funcParam: {
    name: "functionName",
    envVariables: mergedEnvVariables
  }
});

Why This Matters:

• Direct overwrite will delete all environment variables not included in the update
• This can break function functionality if critical variables are removed
• Always preserve existing configuration when making partial updates

Timeout Configuration:

Set via

func.timeout

(in seconds):

• Default timeout varies by runtime
• Maximum timeout depends on runtime version
• Consider function execution time when setting

Timer Triggers:

Configure via

func.triggers

:

• Type:

  timer

  (only supported type)
• Config: Cron expression (7 fields: second minute hour day month week year)
• Examples:

  • "0 0 2 1 * * *"

    - 2:00 AM on 1st of every month

  • "0 30 9 * * * *"

    - 9:30 AM every day

VPC Configuration:

For accessing VPC resources:

{
  vpc: {
    vpcId: "vpc-xxxxx",
    subnetId: "subnet-xxxxx"
  }
}

MCP Tools Reference

Function Management:

• getFunctionList

  - List functions or get function details

• createFunction

  - Create new cloud function

• updateFunctionCode

  - Update function code (runtime cannot change)

• updateFunctionConfig

  - Update function configuration (⚠️ when updating envVariables, must first query and merge with existing values to avoid overwriting)

Logging:

• getFunctionLogs

  - Get function log list (basic info)

• getFunctionLogDetail

  - Get detailed log content by RequestId

• callCloudApi

  (Plan B) - Use

  GetFunctionLogs

  and

  GetFunctionLogDetail

  actions if direct tools unavailable

HTTP Access:

• createFunctionHTTPAccess

  - Create HTTP access for function

• callCloudApi

  (Plan B) - Use

  CreateCloudBaseGWAPI

  action if direct tool unavailable

Triggers:

• manageFunctionTriggers

  - Create or delete function triggers

Console Management

Function Console URLs:

• Function List:

  https://tcb.cloud.tencent.com/dev?envId=${envId}#/scf

• Function Detail:

  https://tcb.cloud.tencent.com/dev?envId=${envId}#/scf/detail?id=${functionName}&NameSpace=${envId}

Console Features:

• View function code and configuration
• Monitor function invocations and performance
• Manage environment variables
• Configure triggers
• View logs and execution history

Common Patterns

Error Handling

exports.main = async (event, context) => {
  try {
    // Function logic
    return {
      code: 0,
      message: "Success",
      data: result
    };
  } catch (error) {
    return {
      code: -1,
      message: error.message,
      data: null
    };
  }
};

Environment Variable Usage

exports.main = async (event, context) => {
  const apiKey = process.env.API_KEY;
  const dbUrl = process.env.DATABASE_URL;
  
  // Use environment variables
};

Database Operations

const cloudbase = require("@cloudbase/node-sdk");

const app = cloudbase.init({
  env: process.env.ENV_ID
});

exports.main = async (event, context) => {
  const db = app.database();
  const result = await db.collection("users").get();
  return result;
};

Best Practices

1. Runtime Selection: Always specify runtime explicitly, use

   Nodejs18.15

   for new projects
2. Code Organization: Keep functions focused and single-purpose
3. Error Handling: Always implement proper error handling
4. Environment Variables: Use env vars for configuration, never hardcode secrets
5. Logging: Add meaningful logs for debugging
6. Testing: Test functions locally when possible before deployment
7. Security: Implement authentication/authorization for HTTP access
8. Performance: Optimize cold start time, use connection pooling for databases
9. Monitoring: Regularly check logs and monitor function performance
10. Documentation: Document function parameters and return values

Related Skills

• cloudrun-development

  - For multi-language backend services

• http-api

  - For HTTP API invocation patterns

• cloudbase-platform

  - For general CloudBase platform knowledge