Connectors

Connectors enable Stack9 to integrate with external services, APIs, databases, and cloud platforms. They provide a unified, configuration-driven way to connect to third-party systems without writing integration code.

What are Connectors?

Connectors are JSON configuration files that define how to connect to external services:

REST APIs - Connect to any HTTP/HTTPS API
Databases - Connect to PostgreSQL, MongoDB, MSSQL, Redis
Cloud Services - Connect to AWS S3, Azure Blob, DynamoDB, OpenSearch
Third-party APIs - Connect to SendGrid, GraphQL endpoints, OpenAPI services

When you define a connector, Stack9 automatically:

✅ Manages authentication and credentials
✅ Handles connection pooling
✅ Secures sensitive data with environment variables
✅ Provides type-safe access in queries and actions
✅ Manages timeouts and retries

Why Use Connectors?

Without Connectors (Manual Integration)

// Scattered API clients, repeated configuration
import axios from 'axios';

const client = axios.create({
  baseURL: process.env.EXTERNAL_API_URL,
  headers: {
    'Authorization': `Bearer ${process.env.API_TOKEN}`,
    'Accept': 'application/json'
  }
});

// Repeated in multiple files
const response = await client.get('/customers');

With Connectors (Stack9 Approach)

{
  "name": "External Service",
  "key": "external_service",
  "type": "rest_api",
  "configuration": {
    "baseUrl": "%%APP_EXTERNAL_API_URL%%",
    "headers": {
      "Authorization": "Bearer %%APP_API_TOKEN%%",
      "Accept": "application/json"
    }
  }
}

Benefits:

✅ Centralized: All API configurations in one place
✅ Secure: Credentials never hardcoded
✅ Reusable: Use in queries, automations, and hooks
✅ Environment-aware: Different configs per environment
✅ Type-safe: TypeScript types generated automatically

Connector File Structure

Connectors are defined in src/connectors/{connector_name}.json:

{
  "key": "unique_connector_key",
  "name": "Human Readable Name",
  "description": "What this connector does",
  "type": "connector_type",
  "module": "module_name",  // Optional
  "configuration": {
    // Type-specific configuration
  }
}

Stack9 Console — Connector detail screen with the Configuration, Code view and Usages tabs open on Configuration, showing key, name, type and connection fields

Native Connectors

Stack9 provides built-in connectors that require no configuration:

stack9_api

Access Stack9's own entity APIs.

{
  "name": "Stack9 API",
  "key": "stack9_api",
  "type": "stack9_api",
  "description": "Native Stack9 API connector"
}

Usage in queries:

{
  "key": "getcustomerlist",
  "connector": "stack9_api",
  "queryTemplate": {
    "method": "post",
    "path": "/customer/search",
    "bodyParams": "{ \"$where\": { \"is_active\": true } }"
  }
}

stack9_db

Direct access to Stack9's database (PostgreSQL or MSSQL).

{
  "key": "stack9_db",
  "name": "Stack9 Database",
  "type": "stack9_db",
  "description": "Native Stack9 database connector",
  "configuration": {
    "client": "pg"  // or "mssql" for SQL Server
  }
}

Use in entity hooks with Knex:

await this.context.db.entity.knex('customers')
  .where({ is_active: true })
  .select('*');

Connector Types

1. REST API Connectors

Connect to any REST API service.

{
  "name": "Address Lookup Service",
  "key": "address_lookup_service",
  "description": "Experian address lookup API",
  "type": "rest_api",
  "configuration": {
    "baseUrl": "https://api.experianaperture.io",
    "headers": {
      "Auth-Token": "%%APP_EXPERIAN_ADDRESS_LOOKUP_TOKEN%%"
    },
    "authentication": {}
  }
}

Configuration Options:

baseUrl (required): Base URL for all API calls
headers (optional): Default headers for all requests
authentication (optional): Authentication configuration

Authentication Types:

Basic Auth

{
  "authentication": {
    "type": "basic",
    "username": "%%APP_API_USERNAME%%",
    "password": "%%APP_API_PASSWORD%%"
  }
}

Bearer Token

{
  "authentication": {
    "type": "bearer",
    "bearer": "%%APP_API_TOKEN%%"
  }
}

API Key

{
  "authentication": {
    "type": "apiKey",
    "apiKey": "%%APP_API_KEY%%"
  }
}

Custom Authorization

{
  "headers": {
    "Authorization": "Basic %%APP_WESTPAC_LOTTERY_SECRET_KEY%%"
  }
}

2. Amazon OpenSearch

Note: Amazon OpenSearch is defined in the ConnectorType enum but not validated in ConnectorSchemaValidator. Support may be limited.

Connect to AWS OpenSearch for full-text search and analytics.

{
  "key": "opensearch",
  "name": "OpenSearch",
  "description": "AWS OpenSearch service",
  "type": "amazon_opensearch",
  "configuration": {
    // Configuration schema not defined in validator
    // Check with Stack9 support for proper configuration
  }
}

3. Amazon S3

Connect to AWS S3 for file storage.

{
  "name": "Document Storage",
  "key": "document_storage",
  "type": "amazon_s3",
  "configuration": {
    "accessKeyId": "%%APP_AWS_S3_ACCESS_KEY_ID%%",
    "secretAccessKeyId": "%%APP_AWS_S3_SECRET_ACCESS_KEY%%",
    "bucketName": "%%APP_S3_BUCKET_NAME%%",
    "s3ForcePathStyle": false
  }
}

Configuration:

accessKeyId: AWS access key
secretAccessKeyId: AWS secret key
bucketName: S3 bucket name
arn (optional): Bucket ARN
s3ForcePathStyle (optional): Use path-style URLs
isCustomS3Endpoint (optional): For S3-compatible services
baseUrl (optional): Custom S3 endpoint URL

4. Azure Blob Storage

Connect to Azure Blob Storage for file storage.

{
  "name": "Azure Documents",
  "key": "azure_documents",
  "type": "azure_blob",
  "configuration": {
    "connectionString": "%%APP_AZURE_CONNECTION_STRING%%",
    "containerName": "%%APP_AZURE_CONTAINER_NAME%%"
  }
}

5. PostgreSQL Database

Connect to external PostgreSQL databases.

{
  "name": "External Database",
  "key": "external_db",
  "type": "postgresql",
  "configuration": {
    "host": "%%APP_DB_HOST%%",
    "port": 5432,
    "databaseName": "%%APP_DB_NAME%%",
    "databaseUsername": "%%APP_DB_USERNAME%%",
    "databasePassword": "%%APP_DB_PASSWORD%%",
    "sslEnabled": true
  }
}

Alternative with Connection String:

{
  "configuration": {
    "connectionString": "%%APP_DB_CONNECTION_STRING%%"
  }
}

6. MongoDB

Connect to MongoDB databases.

{
  "name": "MongoDB Analytics",
  "key": "mongodb_analytics",
  "type": "mongodb",
  "configuration": {
    "host": "%%APP_MONGO_HOST%%",
    "port": 27017,
    "databaseName": "%%APP_MONGO_DB_NAME%%",
    "databaseUsername": "%%APP_MONGO_USERNAME%%",
    "databasePassword": "%%APP_MONGO_PASSWORD%%"
  }
}

7. Redis

Connect to Redis for caching and sessions.

{
  "name": "Redis Cache",
  "key": "redis_cache",
  "type": "redis",
  "configuration": {
    "host": "%%APP_REDIS_HOST%%",
    "port": 6379,
    "password": "%%APP_REDIS_PASSWORD%%"
  }
}

8. GraphQL

Connect to GraphQL APIs.

{
  "name": "GraphQL Service",
  "key": "graphql_service",
  "type": "graphql",
  "configuration": {
    "baseUrl": "%%APP_GRAPHQL_ENDPOINT%%",
    "headers": {
      "Authorization": "Bearer %%APP_GRAPHQL_TOKEN%%"
    },
    "authentication": {
      "type": "bearer",
      "token": "%%APP_GRAPHQL_TOKEN%%"
    }
  }
}

9. SendGrid

Connect to SendGrid for email delivery.

{
  "name": "Email Service",
  "key": "email_service",
  "type": "sendgrid",
  "configuration": {
    "accessToken": "%%APP_SENDGRID_API_KEY%%"
  }
}

10. OpenAPI

Connect to services with OpenAPI specifications.

{
  "name": "OpenAPI Service",
  "key": "openapi_service",
  "type": "open_api",
  "configuration": {
    "specificationUrl": "https://api.example.com/openapi.json",
    "basePath": "/v1",
    "customHeaders": {
      "X-API-Version": "2024-01-01"
    },
    "authentication": {
      "type": "apiKey",
      "apiKey": "%%APP_OPENAPI_KEY%%"
    }
  }
}

11. Amazon DynamoDB

Note: Amazon DynamoDB is defined in the ConnectorType enum but not validated in ConnectorSchemaValidator. Support may be limited.

Connect to AWS DynamoDB.

{
  "key": "dynamodb",
  "name": "DynamoDB",
  "type": "amazon_dynamodb",
  "configuration": {
    // Configuration schema not defined in validator
    // Check with Stack9 support for proper configuration
  }
}

12. Elasticsearch

Connect to Elasticsearch clusters.

{
  "name": "Elasticsearch",
  "key": "elasticsearch",
  "type": "elastic_search",
  "configuration": {
    "nodeOrCloudId": "%%APP_ELASTICSEARCH_NODE%%",
    "auth": {
      "type": "basic",
      "username": "%%APP_ELASTICSEARCH_USERNAME%%",
      "password": "%%APP_ELASTICSEARCH_PASSWORD%%"
    }
  }
}

Environment Variables

Use %%VARIABLE_NAME%% syntax to inject environment variables securely.

Variable Naming Convention

# .env file
APP_EXTERNAL_API_URL=https://api.example.com
APP_API_TOKEN=secret_token_here
APP_AWS_S3_BUCKET_NAME=my-documents

In Connector Configuration

{
  "configuration": {
    "baseUrl": "%%APP_EXTERNAL_API_URL%%",
    "headers": {
      "Authorization": "Bearer %%APP_API_TOKEN%%"
    }
  }
}

Benefits:

🔒 Secrets never committed to version control
🌍 Different values per environment (dev, staging, prod)
🔄 Easy rotation without code changes
✅ Validated at startup

Using Connectors in Query Library

Reference connectors in your queries:

{
  "key": "lookup_address",
  "name": "lookupAddress",
  "connector": "address_lookup_service",
  "queryTemplate": {
    "method": "get",
    "path": "/search",
    "queryParams": {
      "query": "{{searchTerm}}"
    }
  },
  "userParams": {
    "searchTerm": ""
  }
}

When executed, Stack9:

Resolves the connector configuration
Injects environment variables
Applies authentication
Merges headers
Executes the request

Using Connectors in Automations

Use connectors in custom action types:

// action-types/fetch-external-data.ts
export class FetchExternalData extends CustomFunction {
  async exec(): Promise<ActionTypeResponse> {
    // Use connector through query library
    const result = await this.context.services.query.execute(
      'lookup_address',
      { searchTerm: '123 Main St' }
    );

    return { success: true, data: result };
  }
}

Using Connectors in Entity Hooks

Access connector data in hooks:

export class ValidateAddress extends CustomFunction {
  async exec(): Promise<CustomFunctionResponse> {
    const { entity } = this.context;

    // Validate address using external service
    const addressValidation = await this.context.services.query.execute(
      'lookup_address',
      { searchTerm: entity.address }
    );

    if (!addressValidation.valid) {
      return {
        valid: false,
        errors: [{
          field: 'address',
          message: 'Address not found'
        }]
      };
    }

    return { valid: true, entity };
  }
}

Real-World Examples

Example 1: Address Validation Service

{
  "name": "Address Lookup Service",
  "key": "address_lookup_service",
  "description": "Experian address lookup API",
  "type": "rest_api",
  "configuration": {
    "baseUrl": "https://api.experianaperture.io",
    "headers": {
      "Auth-Token": "%%APP_EXPERIAN_ADDRESS_LOOKUP_TOKEN%%"
    }
  }
}

Query using this connector:

{
  "key": "validate_address",
  "connector": "address_lookup_service",
  "queryTemplate": {
    "method": "get",
    "path": "/address/search/v1/autocomplete",
    "queryParams": {
      "country": "AUS",
      "query": "{{address}}"
    }
  }
}

Example 2: Payment Gateway

{
  "name": "Payment Gateway",
  "key": "payment_gateway",
  "type": "rest_api",
  "configuration": {
    "baseUrl": "%%APP_PAYMENT_GATEWAY_URL%%",
    "headers": {
      "Authorization": "Basic %%APP_PAYMENT_GATEWAY_SECRET%%",
      "Accept": "application/json",
      "Content-Type": "application/json"
    }
  }
}

Example 3: Document Storage

{
  "name": "Document Storage",
  "key": "document_storage",
  "type": "amazon_s3",
  "configuration": {
    "accessKeyId": "%%APP_AWS_S3_ACCESS_KEY_ID%%",
    "secretAccessKeyId": "%%APP_AWS_S3_SECRET_ACCESS_KEY%%",
    "bucketName": "customer-documents-prod"
  }
}

Use in action type:

export class UploadDocument extends CustomFunction {
  async exec(): Promise<ActionTypeResponse> {
    const { documentId, fileBuffer } = this.params;

    // Stack9 handles S3 connection through connector
    const s3Key = `documents/${documentId}.pdf`;
    await this.context.services.storage.upload(
      'document_storage',
      s3Key,
      fileBuffer
    );

    return { success: true, key: s3Key };
  }
}

Best Practices

1. Use Descriptive Names

{
  "key": "address_lookup_service",    // ✅ Clear purpose
  "key": "api1"                       // ❌ Unclear
}

2. Always Use Environment Variables

{
  "baseUrl": "%%APP_API_URL%%",              // ✅ Secure
  "baseUrl": "https://api.example.com"       // ❌ Hardcoded
}

3. Add Descriptions

{
  "description": "Experian address lookup API for validating Australian addresses"  // ✅ Helpful
}

4. Organize Headers Logically

{
  "headers": {
    "Accept": "application/json",
    "Content-Type": "application/json",
    "Authorization": "Bearer %%APP_TOKEN%%",
    "X-Custom-Header": "value"
  }
}

5. Use Consistent Naming

# Environment variables
APP_{SERVICE}_{RESOURCE}_{PROPERTY}

# Examples
APP_SENDGRID_API_KEY
APP_AWS_S3_BUCKET_NAME
APP_PAYMENT_GATEWAY_SECRET_KEY

6. Document Authentication Requirements

{
  "description": "Westpac Lottery Service - Requires Basic Auth with base64 encoded credentials"
}

7. Test Connector Configuration

Before deploying, verify:

✅ All environment variables are set
✅ Authentication works
✅ Base URL is correct
✅ Headers are properly formatted

Common Patterns

Multi-Environment Configuration

# .env.development
APP_API_URL=https://api-dev.example.com
APP_API_TOKEN=dev_token

# .env.production
APP_API_URL=https://api.example.com
APP_API_TOKEN=prod_token

Same connector definition works across all environments:

{
  "configuration": {
    "baseUrl": "%%APP_API_URL%%",
    "headers": {
      "Authorization": "Bearer %%APP_API_TOKEN%%"
    }
  }
}

Retry Configuration

For unreliable APIs, configure retries in query:

{
  "connector": "external_api",
  "retryOptions": {
    "maxAttempts": 3,
    "backoff": "exponential",
    "retryOn": [408, 429, 500, 502, 503, 504]
  }
}

Timeout Configuration

Set timeouts to prevent hanging requests:

{
  "connector": "slow_api",
  "timeout": 30000  // 30 seconds
}

Troubleshooting

Connector Not Found

Error: Connector 'my_connector' not found

Solutions:

Check the connector key matches exactly
Ensure the file exists in src/connectors/
Restart the Stack9 application

Authentication Failure

Error: 401 Unauthorized

Solutions:

Verify environment variable is set
Check variable name spelling (%%APP_API_TOKEN%%)
Confirm token is valid and not expired
Test authentication separately with curl

Connection Timeout

Error: ETIMEDOUT or ECONNREFUSED

Solutions:

Verify baseUrl is correct
Check network connectivity
Confirm service is running
Check firewall rules

Environment Variable Not Replaced

Error: Seeing %%APP_VARIABLE%% in logs

Solutions:

Ensure variable is defined in .env
Restart application after adding variables
Check variable name spelling matches exactly

Complete Schema Reference

For the complete, detailed schema reference for all connector types and their configurations, see:

Connector Schema Reference - Authoritative schema definitions for all connector types and their configurations
Query Library Schema Reference - Query templates for using connectors

Next Steps

Now that you understand Connectors, learn about:

Query Library - Use connectors in queries
Action Types - Use connectors in custom actions
Automations - Trigger external APIs in workflows
How-To: Integrate External APIs

Integrating External APIs — connect to third-party services

What are Connectors?​

Why Use Connectors?​

Without Connectors (Manual Integration)​

With Connectors (Stack9 Approach)​

Connector File Structure​

Native Connectors​

stack9_api​

stack9_db​

Connector Types​

1. REST API Connectors​

Basic Auth​

Bearer Token​

API Key​

Custom Authorization​

2. Amazon OpenSearch​

3. Amazon S3​

4. Azure Blob Storage​

5. PostgreSQL Database​

6. MongoDB​

7. Redis​

8. GraphQL​

9. SendGrid​

10. OpenAPI​

11. Amazon DynamoDB​

12. Elasticsearch​

Environment Variables​

Variable Naming Convention​

In Connector Configuration​

Using Connectors in Query Library​

Using Connectors in Automations​

Using Connectors in Entity Hooks​

Real-World Examples​

Example 1: Address Validation Service​

Example 2: Payment Gateway​

Example 3: Document Storage​

Best Practices​

1. Use Descriptive Names​

2. Always Use Environment Variables​

3. Add Descriptions​

4. Organize Headers Logically​

5. Use Consistent Naming​

6. Document Authentication Requirements​

7. Test Connector Configuration​

Common Patterns​

Multi-Environment Configuration​

Retry Configuration​

Timeout Configuration​

Troubleshooting​

Connector Not Found​

Authentication Failure​

Connection Timeout​

Environment Variable Not Replaced​

Complete Schema Reference​

Next Steps​

Related guides​

What are Connectors?

Why Use Connectors?

Without Connectors (Manual Integration)

With Connectors (Stack9 Approach)

Connector File Structure

Native Connectors

stack9_api

stack9_db

Connector Types

1. REST API Connectors

Basic Auth

Bearer Token

API Key

Custom Authorization

2. Amazon OpenSearch

3. Amazon S3

4. Azure Blob Storage

5. PostgreSQL Database

6. MongoDB

7. Redis

8. GraphQL

9. SendGrid

10. OpenAPI

11. Amazon DynamoDB

12. Elasticsearch

Environment Variables

Variable Naming Convention

In Connector Configuration

Using Connectors in Query Library

Using Connectors in Automations

Using Connectors in Entity Hooks

Real-World Examples

Example 1: Address Validation Service

Example 2: Payment Gateway

Example 3: Document Storage

Best Practices

1. Use Descriptive Names

2. Always Use Environment Variables

3. Add Descriptions

4. Organize Headers Logically

5. Use Consistent Naming

6. Document Authentication Requirements

7. Test Connector Configuration

Common Patterns

Multi-Environment Configuration

Retry Configuration

Timeout Configuration

Troubleshooting

Connector Not Found

Authentication Failure

Connection Timeout

Environment Variable Not Replaced

Complete Schema Reference

Next Steps

Related guides