secondlayer

The four developer surfaces around the platform. Same auth across all of them — sign in once with the CLI, every tool inherits the session.

SDK

TypeScript client for Streams, Subgraphs, and Subscriptions. Deploy subgraphs, query tables, manage row-change webhooks — programmatic parity with the CLI.

bun add @secondlayer/sdk @secondlayer/stacks

import { createClient, createStreamsClient } from "@secondlayer/sdk";

const client = createClient({ apiKey: process.env.SL_SERVICE_KEY! });
await client.subgraphs.queryTable("my-watcher", "transfers", { _limit: 10 });
await client.subscriptions.create({ ... });

const streams = createStreamsClient({ apiKey: process.env.SL_STREAMS_API_KEY! });
await streams.events.consume({ types: ["print"], onBatch: async (events) => { ... } });

CLI

One binary for everything you'd otherwise click through dashboards for. Login, deploy, query, manage subscriptions, tail Streams, provision dedicated instances.

bun add -g @secondlayer/cli

sl login                                  # magic-link email
sl subgraphs new my-watcher --template sip-010-balances
sl subgraphs deploy my-watcher.ts         # prompts login if no session
sl subgraphs query my-watcher transfers --filter recipient=SP1...
sl streams events --types print --contract-id SP2...BNS-V2
sl create subscription my-watcher --runtime node

MCP server

Model Context Protocol server so agents (Claude Code, Cursor, any MCP client) can list/query subgraphs, configure subscriptions, and invoke chain tools without you wiring REST calls by hand.

bunx @secondlayer/mcp                     # stdio transport (default)
bunx @secondlayer/mcp --http              # HTTP transport on :3900

// claude_desktop_config.json
{
  "mcpServers": {
    "secondlayer": {
      "command": "bunx",
      "args": ["@secondlayer/mcp"],
      "env": { "SL_SERVICE_KEY": "sk-sl_..." }
    }
  }
}

@secondlayer/stacks

The agent-native Stacks chain SDK. Typed contract reads + writes, AI SDK tool({...}) values, and the on.* filter factories that produce typed Subscription specs.

bun add @secondlayer/stacks

import { on } from "@secondlayer/stacks";

// Typed subscription filter — bind to a subgraph table you own.
const spec = on.transferTo(
  { subgraph: "my-watcher", table: "transfers" },
  "SP1ABC...",
  { asset: "SP1...usdc::usdc-token" },
);

// Available: on.transferTo, on.sip010Transfer, on.sip009Transfer,
//            on.bnsName, on.poxStack, on.sbtcDeposit, on.sbtcWithdrawal