@lti-tool/dynamodb

Installation

npm install @lti-tool/dynamodb

Quick Start

import { LTITool } from '@lti-tool/core';
import { DynamoDbStorage } from '@lti-tool/dynamodb';

const storage = new DynamoDbStorage({
  controlPlaneTable: 'lti-tool-control',
  dataPlaneTable: 'lti-tool-data',
  launchConfigTable: 'lti-tool-launch-config',
  logger: pino('dynamodb-storage'), // optional pino logger
});

const ltiTool = new LTITool({
  stateSecret: new TextEncoder().encode('your-secret'),
  keyPair: await generateKeyPair(), // generate secure keypair
  storage,
});

Features

• Production Ready - Handles high-scale LTI deployments
• Built-in Caching - LRU cache for frequently accessed data
• Three-Table Design - Optimized access patterns
• Auto-cleanup - Expired nonces and sessions removed automatically
• AWS Optimized - Works seamlessly with Lambda and IAM roles

Configuration

Basic Setup

const storage = new DynamoDbStorage({
  controlPlaneTable: 'lti-tool-control', // LMS configurations
  dataPlaneTable: 'lti-tool-data', // nonce and session storage, with ttl
  launchConfigTable: 'lti-tool-launch-config', // LMS client and deployment lookup for optimized critical launch path performance
});

Table Schema

Three-table design optimized for different access patterns:

Control Plane Table (lti-tool-control)

Stores LMS client and deployment configurations.

| Attribute | Type | Description | | --------- | ------ | ------------------------------ | | pk | String | C#<clientId> | | sk | String | # (client) or D#<deployId> | | gsi1pk | String | Type#Client (for listing) | | gsi1sk | String | #<clientId> |

Data Plane Table (lti-tool-data)

Stores sessions and nonces with automatic TTL cleanup.

| Attribute | Type | Description | | --------- | ------ | ------------------------------ | | pk | String | S#<sessionId> or N#<nonce> | | sk | String | Same as pk | | ttl | Number | TTL for auto cleanup |

Launch Config Table (lti-tool-launch-config)

Optimized for fast LTI launch lookups.

| Attribute | Type | Description | | --------- | ------ | ------------------ | | pk | String | <iss>#<clientId> | | sk | String | <deploymentId> |

IAM Permissions

Required DynamoDB permissions for all three tables:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "dynamodb:GetItem",
        "dynamodb:PutItem",
        "dynamodb:UpdateItem",
        "dynamodb:DeleteItem",
        "dynamodb:Query"
      ],
      "Resource": [
        "arn:aws:dynamodb:*:*:table/lti-tool-control",
        "arn:aws:dynamodb:*:*:table/lti-tool-control/index/*",
        "arn:aws:dynamodb:*:*:table/lti-tool-data",
        "arn:aws:dynamodb:*:*:table/lti-tool-launch-config"
      ]
    }
  ]
}

Performance

• Cached reads: ~1ms average
• Cache misses: ~5ms average
• Writes: ~3ms average

Deployment

Terraform Example

# Control plane table
resource "aws_dynamodb_table" "lti_control" {
  name           = "lti-tool-control"
  billing_mode   = "PAY_PER_REQUEST"
  hash_key       = "pk"
  range_key      = "sk"

  attribute {
    name = "pk"
    type = "S"
  }

  attribute {
    name = "sk"
    type = "S"
  }

  attribute {
    name = "gsi1pk"
    type = "S"
  }

  attribute {
    name = "gsi1sk"
    type = "S"
  }

  global_secondary_index {
    name     = "GSI1"
    hash_key = "gsi1pk"
    range_key = "gsi1sk"
  }
}

# Data plane table with TTL
resource "aws_dynamodb_table" "lti_data" {
  name           = "lti-tool-data"
  billing_mode   = "PAY_PER_REQUEST"
  hash_key       = "pk"
  range_key      = "sk"

  attribute {
    name = "pk"
    type = "S"
  }

  attribute {
    name = "sk"
    type = "S"
  }

  ttl {
    attribute_name = "ttl"
    enabled        = true
  }
}

# Launch config table
resource "aws_dynamodb_table" "lti_launch_config" {
  name           = "lti-tool-launch-config"
  billing_mode   = "PAY_PER_REQUEST"
  hash_key       = "pk"
  range_key      = "sk"

  attribute {
    name = "pk"
    type = "S"
  }

  attribute {
    name = "sk"
    type = "S"
  }
}