Dynamo

Reference doc for the sst.aws.Dynamo component.

The Dynamo component lets you add an Amazon DynamoDB table to your app.

Constructor

sst.config.ts

const table = new sst.aws.Dynamo("MyTable", {
  fields: {
    userId: "string",
    noteId: "string"
  },
  primaryIndex: { hashKey: "userId", rangeKey: "noteId" }
});

Parameters

fields

fields · Record<string, 'string' | 'number' | 'binary'> · required

Define the fields used for indexes. You only need to define fields used in indexes, not all table fields.

{
  fields: {
    userId: "string",
    noteId: "string",
    createdAt: "number"
  }
}

Field types cannot be changed after table creation.

primaryIndex

primaryIndex · object · required

Define the table’s primary index.

{
  primaryIndex: { hashKey: "userId", rangeKey: "noteId" }
}

globalIndexes

globalIndexes · Record<string, object>

Configure global secondary indexes. You can have up to 20 global indexes per table.

{
  globalIndexes: {
    CreatedAtIndex: { hashKey: "userId", rangeKey: "createdAt" }
  }
}

Create composite keys with multiple attributes:

{
  globalIndexes: {
    RegionCategoryIndex: {
      hashKey: ["region", "category"],
      rangeKey: "createdAt"
    }
  }
}

localIndexes

localIndexes · Record<string, object>

Configure local secondary indexes. You can have up to 5 local indexes per table.

{
  localIndexes: {
    CreatedAtIndex: { rangeKey: "createdAt" }
  }
}

stream

stream · "keys-only" | "new-image" | "old-image" | "new-and-old-images"

Enable DynamoDB Streams to capture item changes.

{
  stream: "new-and-old-images"
}

Use "new-and-old-images" as a good default since it contains all the data.

Streams are not enabled by default due to associated costs.

ttl

ttl · string

The field name to store Time to Live (TTL) timestamps. Items are deleted when TTL is reached.

{
  ttl: "expiresAt"
}

Properties

name

arn

nodes

Methods

subscribe

SDK

Query the table from your function code:

src/api.ts

import { Resource } from "sst";
import { DynamoDBClient, QueryCommand } from "@aws-sdk/client-dynamodb";

const client = new DynamoDBClient();

await client.send(new QueryCommand({
  TableName: Resource.MyTable.name,
  KeyConditionExpression: "userId = :userId",
  ExpressionAttributeValues: {
    ":userId": { S: "my-user-id" }
  }
}));

Examples

Add a global index

sst.config.ts

new sst.aws.Dynamo("MyTable", {
  fields: {
    userId: "string",
    noteId: "string",
    createdAt: "number"
  },
  primaryIndex: { hashKey: "userId", rangeKey: "noteId" },
  globalIndexes: {
    CreatedAtIndex: { hashKey: "userId", rangeKey: "createdAt" }
  }
});

Subscribe to streams

sst.config.ts

const table = new sst.aws.Dynamo("MyTable", {
  fields: {
    userId: "string",
    noteId: "string"
  },
  primaryIndex: { hashKey: "userId", rangeKey: "noteId" },
  stream: "new-and-old-images"
});

table.subscribe("MySubscriber", "src/subscriber.handler");

Link to a function

sst.config.ts

const table = new sst.aws.Dynamo("MyTable", {
  fields: {
    userId: "string",
    noteId: "string"
  },
  primaryIndex: { hashKey: "userId", rangeKey: "noteId" }
});

new sst.aws.Function("MyFunction", {
  handler: "src/api.handler",
  link: [table]
});