# Blockchains (Blockchain Lab) building blocks

> Open-source repositories under github.com/Blockchains documented as composable building blocks: data APIs and SDKs, an MCP server with blockchain tools for AI agents, tested Solidity contracts, project composers, browser tools and curated fork indexes. Each repo has AGENTS.md (how to work in it), llms.txt and a blocks.json manifest (exports, inputs, outputs, compatible blocks, tests).

Start with the guide (layer map, how to assemble a project, three verified recipes). Then pick blocks from https://blockchains.github.io/blocks.json, read the block's AGENTS.md, install from its entrypoints and run its tests command. Pin a tag or commit. Nothing here requires an API key except Grok (xAI) features.

## Start here
- [Build with Blocks](https://github.com/Blockchains/.github/blob/main/docs/BUILD-WITH-BLOCKS.md): how to assemble projects from these repos, with 3 verified end-to-end recipes
- [blocks.json](https://blockchains.github.io/blocks.json): machine-readable catalogue of every block (31 repos)
- [Blocks schema](https://github.com/Blockchains/.github/blob/main/docs/BLOCKS-SCHEMA.md): blocks.json format ([JSON Schema](https://raw.githubusercontent.com/Blockchains/.github/main/docs/blocks.schema.json))
- [Full text](https://blockchains.github.io/llms-full.txt): guide + schema + every repo's AGENTS.md in one file
- [services.json](https://blockchains.github.io/services.json): the hub's 75 hosted services

## Data, APIs and SDKs
- [blockchainlab-api](https://raw.githubusercontent.com/Blockchains/blockchainlab-api/main/llms.txt): Free, static, CORS-enabled JSON API of 20 blockchain datasets rebuilt nightly from public sources (chainid.network, DefiLlama, L2BEAT, OFAC via 0xB10C, ethereum/EIPs, bitcoin/bips, Blockchain Lab corpus). No key, no backend.
- [blockchainlab-feeds](https://raw.githubusercontent.com/Blockchains/blockchainlab-feeds/main/llms.txt): Public JSON feeds for blockchainlab.com: hackathons/grants/bounties, events, clustered X intel and mentions (public post IDs, links, handles, short trimmed summaries, counts only), built daily.
- [blockchainlab-sdk](https://raw.githubusercontent.com/Blockchains/blockchainlab-sdk/main/llms.txt): Typed TypeScript and Python clients for the Blockchain Lab Open Data API: 20 nightly-rebuilt blockchain datasets (chains, RPC health, DeFi TVL, stablecoins, yields, L2 metrics, hacks, OFAC addresses, EIPs/ERCs/BIPs, grants, hackathons).
- [whitepapers](https://raw.githubusercontent.com/Blockchains/whitepapers/main/llms.txt): Index of the 79 historic whitepapers in the Blockchain Lab PDF library (Bitcoin, Ethereum, Ripple, Stellar, Corda…) as README table, index.json and index.csv; links point at the original files on blockchainlab.com, refreshed weekly.

## Agents and AI
- [blockchainlab-mcp](https://raw.githubusercontent.com/Blockchains/blockchainlab-mcp/main/llms.txt): MCP server (stdio) with 43 read-only blockchain tools for AI agents (Cursor, Claude, Grok, any MCP client) plus the same logic as a JS SDK: datasets from the Open Data API and live on-chain helpers (tx/calldata decoding, gas, ENS, Safe, EIP-712, approvals, MEV, Solana, PSBT). No keys; never signs or sends.

## Smart contracts
- [blockchainlab-labs](https://raw.githubusercontent.com/Blockchains/blockchainlab-labs/main/llms.txt): 54 runnable smart-contract labs: 45 Solidity labs with Foundry tests (storage to reentrancy, AMMs, flash loans, proxies, ERC-7201, fuzzing, invariants, mainnet forks), 4 Noir ZK labs, 4 Cairo/Starknet labs and a Hardhat lab. Each lab is a small, tested, importable contract.
- [forge-dao-governance-token](https://raw.githubusercontent.com/Blockchains/forge-dao-governance-token/main/llms.txt): Composed DAO governance kit: capped ERC-20 with EIP-2612 permit, ERC20Votes delegation and role-based minting (DaoGovernanceToken) plus an OpenZeppelin Governor with settings, simple counting, 4% quorum and a TimelockController (DaoGovernanceGovernor).
- [forge-example-gasless-membership](https://raw.githubusercontent.com/Blockchains/forge-example-gasless-membership/main/llms.txt): Composed gasless membership club: ERC-721 pass with an approver allowlist (MembershipNFT) and an ERC-4337 paymaster that sponsors exactly the join() UserOperation (ClubPaymaster, extends eth-infinitism BasePaymaster v0.9.0), plus a viem front end.
- [forge-example-usd-savings-vault](https://raw.githubusercontent.com/Blockchains/forge-example-usd-savings-vault/main/llms.txt): Composed ERC-4626 savings vault that reports value in USD via a Chainlink feed, with a USD deposit cap, entry fee (max 5%) and RISK_MANAGER_ROLE controls (UsdSavingsVault), plus a viem front end on GitHub Pages.
- [forge-usd-priced-membership-nft](https://raw.githubusercontent.com/Blockchains/forge-usd-priced-membership-nft/main/llms.txt): Composed membership NFT: ERC-721 with max supply, ERC-2981 royalties, pause switch, MINTER/PAUSER roles and a paid mint priced in USD through a Chainlink ETH/USD feed with staleness checks and refunds (UsdPricedMembership). Good base for token-gated apps.

## Composers, CLIs, Actions and templates
- [blockchainlab-compose](https://raw.githubusercontent.com/Blockchains/blockchainlab-compose/main/llms.txt): Idea-to-repo engine behind blockchainlab.com/forge: turns a plain-language token/NFT idea into a tested Foundry project (components from blockchainlab-index, pragma/licence checks, generated glue, tests, deploy script, CI) and optionally creates it under github.com/Blockchains.
- [blockchainlab-starters](https://raw.githubusercontent.com/Blockchains/blockchainlab-starters/main/llms.txt): Template repo of 8 CI-tested starters built on Blockchains forks: foundry-oz-tokens, chainlink-price-feed, uniswap-v4-hook, erc4337-smart-account, hedera-token-sdk, wagmi-rainbowkit-dapp, circom-zk-proof and noir-zk-proof.
- [fork-sync](https://raw.githubusercontent.com/Blockchains/fork-sync/main/llms.txt): Keeps the curated Blockchains forks in line with their upstreams: forks.json lists each fork, upstream, branch and mode (merge via the merge-upstream API, or tracking for forks whose GitHub parent differs from the real upstream); nightly workflow + box-side script.
- [grokhack-forge](https://raw.githubusercontent.com/Blockchains/grokhack-forge/main/llms.txt): Composer for Grok apps: turns an app idea into a working repo (archetype `chat`: Vite + Vercel AI SDK @ai-sdk/xai with streaming and tools; archetype `digest`: Python xai-sdk with structured output on a schedule) using parts from grokhack-index, with CI that makes a real api.x.ai request and a GitHub Pages deploy.
- [grokhack-submissions](https://raw.githubusercontent.com/Blockchains/grokhack-submissions/main/llms.txt): Template repository for The Grok Hack entries: submission.json validated against submission.schema.json, a Node 22 streaming-chat starter for the xAI API, judging notes, and CI that validates, builds/tests, runs a real api.x.ai e2e and scans for secrets.
- [hackathon-entry-template](https://raw.githubusercontent.com/Blockchains/hackathon-entry-template/main/llms.txt): Generic hackathon entry template: README skeleton (problem, solution, architecture, what was built), docs/SUBMISSION.md checklist, .env.example, and CI that scans for secrets and auto-detects Node, Python or Foundry to build and test.
- [sites-monitor](https://raw.githubusercontent.com/Blockchains/sites-monitor/main/llms.txt): Uptime, TLS, SEO, broken-link, Lighthouse and security-header monitoring for the custom-domain sites, with a public status page, JSON results on gh-pages and one auto-managed GitHub issue per failing domain + check.

## Indexes and curated lists
- [awesome-blockchainlab](https://raw.githubusercontent.com/Blockchains/awesome-blockchainlab/main/llms.txt): Curated list of 225 open-source blockchain projects (+11 extended) forked under Blockchains and kept in sync by fork-sync, with a machine-readable forge.json (fork, upstream, category, licence, stars, docs, starters, index links).
- [awesome-grokhack](https://raw.githubusercontent.com/Blockchains/awesome-grokhack/main/llms.txt): Curated list of 99 open-source Grok/xAI integrations (official xAI repos, SDKs, gateways, agent frameworks, coding agents, chat UIs, observability, voice, apps) forked under Blockchains, with machine-readable grok-forge.json.
- [blockchainlab-index](https://raw.githubusercontent.com/Blockchains/blockchainlab-index/main/llms.txt): Nightly machine-readable code index of the curated Blockchains forks: per-repo catalog, every contract/module/circuit as a component with functions, licence and pinned raw URL, capability taxonomy, int8 embeddings, static search shards and SQLite FTS5. Feeds the composers.
- [grokhack-index](https://raw.githubusercontent.com/Blockchains/grokhack-index/main/llms.txt): Nightly index of the Grok/xAI integration surface (endpoints, models, features, env vars, SDK exports, packages, code snippets with commit-pinned URLs) across the forks listed in awesome-grokhack, with a static search UI and an inverted index.

## Apps, browser tools and sites
- [blockchainlab-lens](https://raw.githubusercontent.com/Blockchains/blockchainlab-lens/main/llms.txt): One-click explainer for Etherscan-family and Blockscout explorers: a Manifest V3 extension and a bookmarklet that open the matching blockchainlab-tools page. Its URL detector (`extension/detect.js`) is a reusable UMD module.
- [blockchainlab-tools](https://raw.githubusercontent.com/Blockchains/blockchainlab-tools/main/llms.txt): 26 client-side blockchain developer tools (gas, units, ABI, tx decoder, ENS, storage slots, Merkle, Safe, EIP-712, approvals, MEV, Solana, PSBT...) as static pages with deep links, plus the shared ES-module logic (`assets/core.js`, `assets/core2.js`) usable from Node or the browser.
- [blockchains.github.io](https://blockchains.github.io/llms.txt): Blockchain Lab Hub: static GitHub Pages site with 75 free services (AI briefs via Grok, gas/RPC/chain monitors, finders, feeds), machine-readable services.json, health data, and the org-wide llms.txt and blocks.json catalogue.
- [grok-release-radar](https://raw.githubusercontent.com/Blockchains/grok-release-radar/main/llms.txt): Daily digest app composed by grokhack-forge: collects real GitHub release activity for tracked Grok-integration repos and summarises it with the official xai-sdk (gRPC) using structured output, published to GitHub Pages by Actions.
- [grok-tools-chat](https://raw.githubusercontent.com/Blockchains/grok-tools-chat/main/llms.txt): Browser chat app composed by grokhack-forge: Grok via Vercel AI SDK @ai-sdk/xai with streaming and local tools (calculator, time, live GitHub repo lookup) plus xAI web search; visitors bring their own key, sent only to api.x.ai.

## Docs and learning
- [.github](https://raw.githubusercontent.com/Blockchains/.github/main/llms.txt): Org-wide defaults (issue/PR templates, CONTRIBUTING, CODE_OF_CONDUCT, SECURITY) plus the building-block docs: BUILD-WITH-BLOCKS.md, BLOCKS-SCHEMA.md, blocks.schema.json and the workflow that validates every repo's blocks.json.
- [blockchain-dev-roadmap](https://raw.githubusercontent.com/Blockchains/blockchain-dev-roadmap/main/llms.txt): Curated 2026 developer path from zero to shipping production smart contracts in 13 stages; every stage links concepts, primary docs, a runnable lab and a free tool.
- [blockchain-interview-questions](https://raw.githubusercontent.com/Blockchains/blockchain-interview-questions/main/llms.txt): 54 blockchain and smart-contract interview questions with concise answers, each linked to a runnable lab, a free tool or an explainer.
- [Blockchains](https://raw.githubusercontent.com/Blockchains/Blockchains/main/llms.txt): GitHub profile README for Ismail Malik / Blockchain Lab: live sites, the open-source toolkit and pointers to Build with Blocks.
- [hackathons](https://raw.githubusercontent.com/Blockchains/hackathons/main/llms.txt): Blockchain Lab hackathon tracker: one GitHub issue per open blockchain/web3 hackathon (issue forms for hackathons and submissions) plus a README table of verified upcoming events.

## Optional
- [blockchainlab-index catalog](https://raw.githubusercontent.com/Blockchains/blockchainlab-index/main/catalog.json): ~240 indexed forks with pinned commits, licences and per-repo `reuse` install lines
- [Fork reuse notes](https://raw.githubusercontent.com/Blockchains/blockchainlab-index/main/taxonomy/reuse.json): how to reuse each category of fork
- [awesome-blockchainlab forge.json](https://raw.githubusercontent.com/Blockchains/awesome-blockchainlab/main/forge.json): curated forks with docs and starters
- [grokhack-index parts](https://blockchains.github.io/grokhack-index/data/parts.json): Grok/xAI integration parts