streamstore

Developer-friendly & type-safe TypeScript SDK specifically catered to leverage streamstore API.

Summary

S2 API: Serverless API for streaming data backed by object storage.

Table of Contents

• streamstore
  • SDK Installation
  • Requirements
  • SDK Example Usage
  • Authentication
  • Available Resources and Operations
  • Standalone functions
  • Server-sent event streaming
  • Pagination
  • Retries
  • Error Handling
  • Server Selection
  • Custom HTTP Client
  • Debugging
• Development
  • Maturity
  • Contributions

SDK Installation

The SDK can be installed with either npm, pnpm, bun or yarn package managers.

NPM

npm add @s2-dev/streamstore

PNPM

pnpm add @s2-dev/streamstore

Bun

bun add @s2-dev/streamstore

Yarn

yarn add @s2-dev/streamstore zod

# Note that Yarn does not install peer dependencies automatically. You will need
# to install zod as shown above.

Note

This package is published with CommonJS and ES Modules (ESM) support.

Model Context Protocol (MCP) Server

This SDK is also an installable MCP server where the various SDK methods are exposed as tools that can be invoked by AI applications.

Node.js v20 or greater is required to run the MCP server from npm.

Claude installation steps

Add the following server definition to your claude_desktop_config.json file:

{
  "mcpServers": {
    "S2": {
      "command": "npx",
      "args": [
        "-y", "--package", "@s2-dev/streamstore",
        "--",
        "mcp", "start",
        "--access-token", "..."
      ]
    }
  }
}

Cursor installation steps

Create a .cursor/mcp.json file in your project root with the following content:

{
  "mcpServers": {
    "S2": {
      "command": "npx",
      "args": [
        "-y", "--package", "@s2-dev/streamstore",
        "--",
        "mcp", "start",
        "--access-token", "..."
      ]
    }
  }
}

You can also run MCP servers as a standalone binary with no additional dependencies. You must pull these binaries from available Github releases:

curl -L -o mcp-server \
    https://github.com/{org}/{repo}/releases/download/{tag}/mcp-server-bun-darwin-arm64 && \
chmod +x mcp-server

If the repo is a private repo you must add your Github PAT to download a release -H "Authorization: Bearer {GITHUB_PAT}".

{
  "mcpServers": {
    "Todos": {
      "command": "./DOWNLOAD/PATH/mcp-server",
      "args": [
        "start"
      ]
    }
  }
}

For a full list of server arguments, run:

npx -y --package @s2-dev/streamstore -- mcp start --help

Requirements

For supported JavaScript runtimes, please consult RUNTIMES.md.

SDK Example Usage

Example

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.accessTokens.listAccessTokens({});

  console.log(result);
}

run();

Authentication

Per-Client Security Schemes

This SDK supports the following security scheme globally:

Name	Type	Scheme	Environment Variable
accessToken	http	HTTP Bearer	S2_ACCESS_TOKEN

To authenticate with the API the accessToken parameter must be set when initializing the SDK client instance. For example:

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.accessTokens.listAccessTokens({});

  console.log(result);
}

run();

Available Resources and Operations

Available methods

accessTokens

• listAccessTokens - List access tokens.
• issueAccessToken - Issue a new access token.
• revokeAccessToken - Revoke an access token.

basins

• listBasins - List basins.
• createBasin - Create a basin.
• getBasinConfig - Get basin config.
• createOrReconfigureBasin - Create or reconfigure a basin.
• deleteBasin - Delete a basin.
• reconfigureBasin - Reconfigure a basin.

metrics

• accountMetrics - Get account level metrics.
• basinMetrics - Get metrics for a basin.
• streamMetrics - Get metrics for a stream.

records

• read - Retrieve records.
• append - Append records.
• checkTail - Check the tail.

streams

• listStreams - List streams.
• createStream - Create a stream.
• getStreamConfig - Get stream configuration.
• createOrReconfigureStream - Create or reconfigure a stream.
• deleteStream - Delete a stream.
• reconfigureStream - Reconfigure a stream.

Standalone functions

All the methods listed above are available as standalone functions. These functions are ideal for use in applications running in the browser, serverless runtimes or other environments where application bundle size is a primary concern. When using a bundler to build your application, all unused functionality will be either excluded from the final bundle or tree-shaken away.

To read more about standalone functions, check FUNCTIONS.md.

Available standalone functions

• accessTokensIssueAccessToken - Issue a new access token.
• accessTokensListAccessTokens - List access tokens.
• accessTokensRevokeAccessToken - Revoke an access token.
• basinsCreateBasin - Create a basin.
• basinsCreateOrReconfigureBasin - Create or reconfigure a basin.
• basinsDeleteBasin - Delete a basin.
• basinsGetBasinConfig - Get basin config.
• basinsListBasins - List basins.
• basinsReconfigureBasin - Reconfigure a basin.
• metricsAccountMetrics - Get account level metrics.
• metricsBasinMetrics - Get metrics for a basin.
• metricsStreamMetrics - Get metrics for a stream.
• recordsAppend - Append records.
• recordsCheckTail - Check the tail.
• recordsRead - Retrieve records.
• streamsCreateOrReconfigureStream - Create or reconfigure a stream.
• streamsCreateStream - Create a stream.
• streamsDeleteStream - Delete a stream.
• streamsGetStreamConfig - Get stream configuration.
• streamsListStreams - List streams.
• streamsReconfigureStream - Reconfigure a stream.

Server-sent event streaming

Server-sent events are used to stream content from certain operations. These operations will expose the stream as an async iterable that can be consumed using a for await...of loop. The loop will terminate when the server no longer has any events to send and closes the underlying connection.

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.records.read({
    stream: "<value>",
    s2Basin: "<value>",
  });

  for await (const event of result) {
    // Handle the event
    console.log(event);
  }
}

run();

Pagination

Some of the endpoints in this SDK support pagination. To use pagination, you make your SDK calls as usual, but the returned response object will also be an async iterable that can be consumed using the for await...of syntax.

Here's an example of one such pagination call:

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.basins.listBasins({});

  for await (const page of result) {
    console.log(page);
  }
}

run();

Retries

Some of the endpoints in this SDK support retries. If you use the SDK without any configuration, it will fall back to the default retry strategy provided by the API. However, the default retry strategy can be overridden on a per-operation basis, or across the entire SDK.

To change the default retry strategy for a single API call, simply provide a retryConfig object to the call:

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.accessTokens.listAccessTokens({}, {
    retries: {
      strategy: "backoff",
      backoff: {
        initialInterval: 1,
        maxInterval: 50,
        exponent: 1.1,
        maxElapsedTime: 100,
      },
      retryConnectionErrors: false,
    },
  });

  console.log(result);
}

run();

If you'd like to override the default retry strategy for all operations that support retries, you can provide a retryConfig at SDK initialization:

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  retryConfig: {
    strategy: "backoff",
    backoff: {
      initialInterval: 1,
      maxInterval: 50,
      exponent: 1.1,
      maxElapsedTime: 100,
    },
    retryConnectionErrors: false,
  },
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.accessTokens.listAccessTokens({});

  console.log(result);
}

run();

Error Handling

S2Error is the base class for all HTTP error responses. It has the following properties:

Property	Type	Description
error.message	string	Error message
error.statusCode	number	HTTP response status code eg 404
error.headers	Headers	HTTP response headers
error.body	string	HTTP body. Can be empty string if no body is returned.
error.rawResponse	Response	Raw HTTP response
error.data$		Optional. Some errors may contain structured data. See Error Classes.

Example

import { S2 } from "@s2-dev/streamstore";
import * as errors from "@s2-dev/streamstore/models/errors";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  try {
    const result = await s2.accessTokens.listAccessTokens({});

    console.log(result);
  } catch (error) {
    // The base class for HTTP error responses
    if (error instanceof errors.S2Error) {
      console.log(error.message);
      console.log(error.statusCode);
      console.log(error.body);
      console.log(error.headers);

      // Depending on the method different errors may be thrown
      if (error instanceof errors.ErrorResponse) {
        console.log(error.data$.code); // string
        console.log(error.data$.message); // string
      }
    }
  }
}

run();

Error Classes

Primary errors:

• S2Error: The base class for HTTP error responses.
  • ErrorResponse: .

Less common errors (9)

Network errors:

• ConnectionError: HTTP client was unable to make a request to a server.
• RequestTimeoutError: HTTP request timed out due to an AbortSignal signal.
• RequestAbortedError: HTTP request was aborted by the client.
• InvalidRequestError: Any input used to create a request is invalid.
• UnexpectedClientError: Unrecognised or unexpected error.

Inherit from S2Error:

• FencingToken: Fencing token did not match. The expected fencing token is returned. Status code 412. Applicable to 1 of 21 methods.*
• SeqNum: Sequence number did not match the tail of the stream. The expected next sequence number is returned. Status code 412. Applicable to 1 of 21 methods.*
• TailResponse: . Status code 416. Applicable to 1 of 21 methods.*
• ResponseValidationError: Type mismatch between the data returned from the server and the structure expected by the SDK. See error.rawValue for the raw value and error.pretty() for a nicely formatted multi-line string.

* Check the method documentation to see if the error is applicable.

Server Selection

Override Server URL Per-Client

The default server can be overridden globally by passing a URL to the serverURL: string optional parameter when initializing the SDK client instance. For example:

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  serverURL: "https://aws.s2.dev/v1",
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.accessTokens.listAccessTokens({});

  console.log(result);
}

run();

Override Server URL Per-Operation

The server URL can also be overridden on a per-operation basis, provided a server list was specified for the operation. For example:

import { S2 } from "@s2-dev/streamstore";

const s2 = new S2({
  accessToken: process.env["S2_ACCESS_TOKEN"] ?? "",
});

async function run() {
  const result = await s2.streams.listStreams({
    s2Basin: "<value>",
  }, {
    serverURL: "https://.b.aws.s2.dev/v1",
  });

  for await (const page of result) {
    console.log(page);
  }
}

run();

Custom HTTP Client

The TypeScript SDK makes API calls using an HTTPClient that wraps the native Fetch API. This client is a thin wrapper around fetch and provides the ability to attach hooks around the request lifecycle that can be used to modify the request or handle errors and response.

The HTTPClient constructor takes an optional fetcher argument that can be used to integrate a third-party HTTP client or when writing tests to mock out the HTTP client and feed in fixtures.

The following example shows how to use the "beforeRequest" hook to to add a custom header and a timeout to requests and how to use the "requestError" hook to log errors:

import { S2 } from "@s2-dev/streamstore";
import { HTTPClient } from "@s2-dev/streamstore/lib/http";

const httpClient = new HTTPClient({
  // fetcher takes a function that has the same signature as native `fetch`.
  fetcher: (request) => {
    return fetch(request);
  }
});

httpClient.addHook("beforeRequest", (request) => {
  const nextRequest = new Request(request, {
    signal: request.signal || AbortSignal.timeout(5000)
  });

  nextRequest.headers.set("x-custom-header", "custom value");

  return nextRequest;
});

httpClient.addHook("requestError", (error, request) => {
  console.group("Request Error");
  console.log("Reason:", `${error}`);
  console.log("Endpoint:", `${request.method} ${request.url}`);
  console.groupEnd();
});

const sdk = new S2({ httpClient });

Debugging

You can setup your SDK to emit debug logs for SDK requests and responses.

You can pass a logger that matches console's interface as an SDK option.

Warning

Beware that debug logging will reveal secrets, like API tokens in headers, in log messages printed to a console or files. It's recommended to use this feature only during local development and not in production.

import { S2 } from "@s2-dev/streamstore";

const sdk = new S2({ debugLogger: console });

You can also enable a default debug logger by setting an environment variable S2_DEBUG to true.

Development

Maturity

This SDK is in beta, and there may be breaking changes between versions without a major version update. Therefore, we recommend pinning usage to a specific package version. This way, you can install the same version each time without breaking changes unless you are intentionally looking for the latest version.

Contributions

While we value open-source contributions to this SDK, this library is generated programmatically. Any manual changes added to internal files will be overwritten on the next generation. We look forward to hearing your feedback. Feel free to open a PR or an issue with a proof of concept and we'll do our best to include it in a future release.

SDK Created by Speakeasy