Secondlayer

Agent-native developer tools for Stacks. Dedicated indexing + real-time subgraphs + a viem-style chain SDK — exposed through one API, one auth model, and three interchangeable front-ends (CLI, SDK, MCP).

Two ways to run it:

• Hosted — dedicated per-project Postgres + API + subgraph processor. Hobby is free (auto-pauses after 7d idle); paid tiers start at $149/mo.
• Self-host — the whole stack is MIT-licensed. docker compose up gets you indexer + API + processor on your own hardware. See docker/oss/README.md.

What's shipped

• Subgraphs — defineSubgraph() declares event filters + column schema; the processor indexes the chain into a typed Postgres view you query over REST.
• Subscriptions — per-row HTTP webhooks from subgraph tables. Signed Standard Webhooks POSTs, 7× retries with backoff, circuit-breaks at 20 consecutive failures, 6 wire formats (standard-webhooks, inngest, trigger, cloudflare, cloudevents, raw), historical replay by block range.
• @secondlayer/stacks — viem-style chain SDK: typed contract calls, wallets, BNS, transaction builders, and AI-SDK tool({...}) values.

Beta Quickstart (Hosted)

This path gets a new beta user from zero to a live indexed table and webhook receiver. The CLI resolves your active project and mints short-lived tenant credentials for each command, so you do not need to copy service keys unless you are using the SDK, MCP, or raw REST.

bun add -g @secondlayer/cli

sl login
sl project create my-app
sl project use my-app
sl instance create --plan hobby

sl subgraphs scaffold SP1234ABCD.my-contract -o subgraphs/my-contract.ts
sl subgraphs deploy subgraphs/my-contract.ts --start-block <recent-block>
sl subgraphs query my-contract <table> --sort _block_height --order desc

sl create subscription my-hook \
  --runtime node \
  --subgraph my-contract \
  --table <table> \
  --url https://<receiver-host>/webhook

sl subgraphs scaffold writes subgraphs/my-contract.ts, creates or updates the local package.json, and runs bun install by default. Use --no-install only when you want to run bun install yourself before deploy.

Use --start-block for fast demos; it overrides the definition for that deploy without rewriting your source file. For Trigger.dev or Cloudflare receivers, add --auth-token <token> when creating or updating the subscription.

Full walkthrough: packages/subgraphs/QUICKSTART.md. Full command reference: packages/cli/README.md.

Agent-native golden path

1. Give an agent the contract address and the events or calls you care about.
2. The agent scaffolds a defineSubgraph() from the contract ABI, validates it, and deploys it to your dedicated instance.
3. Query the generated table over REST, SDK, CLI, or MCP.
4. Add a subscription on that table when the rows should trigger another system.
5. Replay by block range when a receiver changes or misses deliveries.

Reviewable walkthrough: packages/subgraphs/QUICKSTART.md.

Packages

Package	Description
@secondlayer/cli	sl binary — auth, project/instance lifecycle, subgraph deploy, Clarity code-gen
@secondlayer/sdk	TypeScript SDK — typed subgraph queries, webhooks
@secondlayer/mcp	MCP server — exposes subgraphs + scaffolding to AI agents
@secondlayer/stacks	viem-style Stacks client — public/wallet, BNS, AI-SDK tools
@secondlayer/subgraphs	defineSubgraph() — declarative schema, triggers + event handlers
@secondlayer/shared	Shared db, schemas, crypto helpers
@secondlayer/api	REST API — platform + dedicated + OSS modes

Surfaces

CLI

sl login
sl project use my-app
sl subgraphs deploy ./my-subgraph.ts --start-block <recent-block>
sl subgraphs query my-subgraph transfers --sort _block_height --order desc
sl create subscription transfer-hook --runtime node --subgraph my-subgraph --table transfers --url https://example.com/webhook

SDK

import { SecondLayer } from "@secondlayer/sdk"

const sl = new SecondLayer({
  baseUrl: "https://<slug>.secondlayer.tools",
  apiKey: process.env.SL_SERVICE_KEY,
})

const { data } = await sl.subgraphs.queryTable("transfers", "events", {
  filters: { sender: "SP1234..." },
  sort: "_block_height",
  order: "desc",
  limit: 25,
})

REST API

curl -H "Authorization: Bearer $SL_SERVICE_KEY" \
  "https://<slug>.secondlayer.tools/api/subgraphs/transfers/events?_sort=_block_height&_order=desc&_limit=25"

MCP (AI agents)

Point Claude Desktop, Cursor, or any MCP client at bunx -p @secondlayer/mcp secondlayer-mcp with SECONDLAYER_API_URL=https://<slug>.secondlayer.tools and SL_SERVICE_KEY set. See packages/mcp/README.md.

Self-hosting

git clone https://github.com/ryanwaits/secondlayer
cd secondlayer
cp docker/.env.example docker/.env   # fill in secrets
docker compose -f docker/docker-compose.yml up -d

See docker/oss/README.md for the OSS-mode quickstart and docker/docs/ for operations, backups, and dedicated hosting internals.

Development

bun install
bun run build
bun run typecheck
bun run test

Releases flow through Changesets — bun run version to bump, bun run release to publish.

License

MIT