Claude Skills by claude-dev-suite

Biome linter and formatter for JavaScript/TypeScript. Covers configuration, rules, and integration patterns. Replaces ESLint + Prettier for faster development experience. USE WHEN: user mentions "biome", "linting", "formatting", "code style", "biome.json", asks about "setup linter", "format code", "migrate from ESLint", "migrate from Prettier", "biome rules", "biome configuration" DO NOT USE FOR: ESLint configuration - Biome is an ESLint replacement, Prettier configuration - Biome is a Pret...

Application caching patterns. Redis caching, in-memory caches, HTTP caching, cache invalidation strategies, cache-aside, write-through, and CDN caching. USE WHEN: user mentions "caching", "cache invalidation", "Redis cache", "HTTP cache", "CDN caching", "cache-aside", "write-through", "TTL", "stale-while-revalidate" DO NOT USE FOR: Redis as database/queue - use `redis` or `job-queues`; browser storage - use frontend skills

Clean code principles. Covers naming, functions, and readability. Use when writing or reviewing code for quality. USE WHEN: user mentions "code quality", "readability", "refactor", "clean up code", "naming", "magic numbers", asks about "how to write better code", "code smells", "DRY", "KISS", "YAGNI", "single responsibility" DO NOT USE FOR: SOLID principles - use `solid-principles` instead, Git workflow - use `git-workflow` instead, Performance optimization - use `performance` instead

Error handling patterns across languages and frameworks. Custom error classes, global exception handlers, Problem Details (RFC 9457), error boundaries (React), Result types, and structured error responses. USE WHEN: user mentions "error handling", "exception handler", "error boundary", "custom error", "Problem Details", "error response", "global error handler" DO NOT USE FOR: logging errors - use logging skills; error tracking services - use `error-tracking`

Event-driven architecture patterns and best practices. Covers Saga, Outbox, CQRS, Event Sourcing, and messaging patterns for distributed systems. USE WHEN: user mentions "event-driven", "Saga", "Outbox pattern", "CQRS", "Event Sourcing", "distributed transactions", "eventual consistency", "message broker", "event bus", asks about "microservices communication", "async patterns", "compensating transactions" DO NOT USE FOR: Simple pub/sub - use messaging framework skills (Kafka, RabbitMQ), RES...

Feature flag management. LaunchDarkly, Unleash, Flagsmith, and custom implementations. Gradual rollouts, A/B testing, kill switches, and flag lifecycle management. USE WHEN: user mentions "feature flag", "feature toggle", "LaunchDarkly", "Unleash", "Flagsmith", "gradual rollout", "A/B test", "canary release", "kill switch" DO NOT USE FOR: CI/CD deployment strategies - use `github-actions`; environment config - use environment variable patterns

Git workflow best practices. Covers branching, commits, and collaboration. Use for version control guidance. USE WHEN: user mentions "git", "commit", "branch", "pull request", "PR", "merge", "rebase", "version control", asks about "commit message", "branching strategy", "git best practices", "conventional commits", "how to write PR description" DO NOT USE FOR: Git commands syntax - use git documentation, GitHub Actions CI/CD - use ci-cd skills, Code review quality - use `code-reviewer` agent

Open source readiness best practices. Covers licensing, documentation, community health, CI/CD, compliance, legal, and packaging. USE WHEN: user mentions "open source", "license", "LICENSE", "CONTRIBUTING", "CODE_OF_CONDUCT", "CHANGELOG", "open source readiness", "community health", "OSS compliance", "SPDX", "CLA", "DCO", "OpenSSF", "SBOM", "release automation", "npm publish", "make project open source", "prepare for open source" DO NOT USE FOR: Git workflow and branching - use git-workflow...

Web performance optimization. Covers frontend, backend, and database optimization. Use for performance reviews. USE WHEN: user mentions "performance", "slow", "optimization", "Core Web Vitals", "LCP", "INP", "CLS", "bundle size", "lazy load", "caching", "N+1 query", "memory leak", asks about "how to speed up", "improve performance", "reduce load time", "database optimization" DO NOT USE FOR: Algorithm complexity - use computer science fundamentals, Code quality/readability - use `clean-code...

Python static analysis with ruff, mypy, pyright. Type checking and linting best practices. USE WHEN: "type checking", "mypy", "pyright", "ruff", "linting", "static analysis", "type error", "type hints", "pylint", "flake8", "black", "isort", "code quality" DO NOT USE FOR: Basic type hint syntax - use languages/python skill DO NOT USE FOR: Runtime validation - use Pydantic

Application resilience patterns. Circuit breakers, retries with backoff, bulkheads, timeouts, fallbacks, and health checks. Polly (.NET), resilience4j (Java), cockatiel (Node.js). USE WHEN: user mentions "circuit breaker", "retry", "backoff", "bulkhead", "resilience", "fault tolerance", "Polly", "resilience4j", "fallback" DO NOT USE FOR: error handling basics - use language skills; monitoring - use `opentelemetry`

Ruff Python linter and formatter. Covers configuration in pyproject.toml, rule selection, auto-fix, and integration with editors and CI. Use when configuring or troubleshooting Python code quality tooling. USE WHEN: user mentions "ruff", "ruff check", "ruff format", "python linting", "pyproject.toml linting", "isort alternative", "black alternative", "flake8 replacement", "python formatter" DO NOT USE FOR: ESLint/Prettier (JavaScript), mypy type checking

SOLID design principles. Covers SRP, OCP, LSP, ISP, DIP. Use when designing classes and modules. USE WHEN: user mentions "SOLID", "single responsibility", "open closed", "Liskov", "interface segregation", "dependency inversion", "dependency injection", asks about "class design", "OOP principles", "extensibility", "abstraction", "how to design classes" DO NOT USE FOR: General code quality - use `clean-code` instead, Specific patterns - use design patterns skills, Language-specific OOP - use ...

Token optimization best practices for MCP server and tool interactions. Minimizes token consumption while maintaining effectiveness. USE WHEN: user mentions "token usage", "optimize tokens", "reduce API calls", "MCP efficiency", asks about "how to use less tokens", "MCP best practices", "limit output size", "efficient queries" DO NOT USE FOR: Code optimization - use `performance` instead, Text compression - this is about API usage patterns, Cost optimization (infrastructure) - use cloud/Dev...

Bitcoin Core descriptors wallet: createwallet, importdescriptors, multipath, ranges, watch-only, signing wallets, multisig coordination. Replaces legacy BDB wallet. USE WHEN: setting up Bitcoin Core wallet, watching xpubs, building signing pipelines via Core.

Bitcoin Core indexes: txindex, blockfilterindex (BIP157/158), coinstatsindex. Disk costs, rebuild times, when each is needed. USE WHEN: choosing which indexes to enable, troubleshooting "txid not found", integrating with electrs / fulcrum / LN nodes.

Bitcoin Knots: Luke Dashjr's Bitcoin Core fork with stricter mempool policy and additional configuration. Differences vs Core, when to consider, compatibility. USE WHEN: evaluating Knots for stricter mempool policy, reviewing a node deployment that uses Knots, understanding policy divergence between Core and Knots.

Running Bitcoin Core in production: bitcoin.conf reference, sections, pruning, signet, dbcache, mempool tuning, network bind, Tor, IBD considerations, debug.log analysis. USE WHEN: deploying a node, tuning performance, debugging IBD issues, configuring multi-network nodes.

Bitcoin Core release engineering: Guix reproducible builds, signed release tarballs, deterministic outputs, code-signing keys, the release process, security disclosure. USE WHEN: building Bitcoin Core from source for verification, understanding release security, contributing to consensus-critical code.

Bitcoin Core REST interface: read-only HTTP endpoints for blocks, txs, UTXOs, headers, mempool. No auth, no rate limit. Useful for high-throughput read services. USE WHEN: building read-only services that don't need RPC auth, fetching tx/block data efficiently, integrating with explorers.

Bitcoin Core JSON-RPC interface: authentication (cookie, rpcauth), wallet vs node RPCs, common verbs (getblockchaininfo, getrawtransaction, scantxoutset, importdescriptors, walletprocesspsbt, submitpackage, testmempoolaccept), error handling. USE WHEN: scripting bitcoind, integrating a service, debugging RPC errors.

ZeroMQ notifications from Bitcoin Core: rawblock, rawtx, hashblock, hashtx, sequence. Subscribe over TCP/IPC, integration patterns for Electrs, BTCPay, Lightning nodes. USE WHEN: building real-time integrations with bitcoind, monitoring mempool sequence, integrating LN nodes.

Adaptor signatures: pre-signature paired with a "secret" such that publishing a valid signature reveals the secret, and vice versa. Foundational for atomic swaps, scriptless scripts, DLCs, Submarine Swaps trustless variants, PTLCs (Point Time-Locked Contracts). USE WHEN: designing atomic swaps, evaluating PTLCs vs HTLCs, building DLCs, understanding scriptless scripts.

BIP32 hierarchical deterministic key derivation: master key from seed, hardened vs unhardened derivation, xpub/xprv encoding, fingerprints, child-key chaining, key origin paths. USE WHEN: building HD wallets, deriving addresses, parsing xpubs, validating descriptors with key origin.

Discreet Log Contracts: smart contracts on Bitcoin via oracle attestations + adaptor signatures. Oracle publishes nonces upfront, reveals signed outcomes; CETs (Contract Execution Transactions) enforce payouts. No on-chain footprint of the contract logic. USE WHEN: building betting / prediction markets, parametric insurance, derivatives, oracle-driven settlements on Bitcoin.

ECDSA signatures over secp256k1: sign/verify, deterministic-k (RFC6979), low-s (BIP146), DER encoding, malleability, recoverable signatures. USE WHEN: signing legacy/SegWit-v0 inputs, verifying legacy signatures, debugging "non-canonical signature" errors.

FROST (Flexible Round-Optimised Schnorr Threshold): t-of-n threshold signing on secp256k1. n participants share a key via Distributed Key Generation (DKG) or trusted dealer; any t can produce a Schnorr signature. Differs from MuSig2 (which is n-of-n). USE WHEN: t-of-n threshold custody (e.g., 3-of-5 board signatures) with single-sig appearance on chain, federated services, multi-sig with availability.

MuSig2 (BIP327): two-round Schnorr key aggregation for n-of-n multisig. Aggregates n public keys into a single 32-byte x-only pubkey indistinguishable from a single-sig. Used in Taproot cooperative spends. Quick refs: protocol round-trip, key aggregation math, common attacks. USE WHEN: implementing n-of-n cooperative Taproot signing, designing Lightning Taproot channels, joint custody.

BIP340 Schnorr signatures over secp256k1: sign/verify, x-only pubkeys, tagged hashes, batch verification, key tweaking. Building block for Taproot, MuSig2, FROST, adaptor signatures, DLCs. Quick refs: signing pseudocode, batch verification, common mistakes. USE WHEN: signing/verifying Taproot key-path or Tapscript spends, designing aggregation protocols, reading BIP340.

secp256k1 elliptic curve: parameters, group law, key encoding, point serialization, library bindings (libsecp256k1 in C, Rust, Python). USE WHEN: low-level key/point operations, debugging signature failures, understanding why Bitcoin uses this curve specifically.

BitBox02 (Shift Crypto, Switzerland): Multi Edition (BTC + altcoins), Bitcoin-Only Edition. BitBoxApp, side-channel-resistant SE, NFC, USB-C. USE WHEN: integrating with BitBox02, evaluating European HW options.

Coldcard hardware wallets (Coinkite): Mk4, Q. Bitcoin-only firmware, airgap support via SD card / NFC / QR, BIP85, MuSig2 (experimental), Trick PINs. USE WHEN: integrating with Coldcard, supporting Mk4 / Q, designing airgap signing flows.

HWI (Hardware Wallet Interface): standardized Python API across HW vendors (Trezor, Ledger, Coldcard, BitBox02, Jade, etc.). Used by Bitcoin Core, Sparrow, Specter for cross-vendor signing. USE WHEN: integrating multi-vendor HW signing, building wallets that support several HW.

Blockstream Jade: open-source HW wallet. Optional offline mode via QR / SD / USB, Liquid + Bitcoin support, "Pinserver" online mode for blind signing. USE WHEN: integrating with Jade, supporting Liquid + Bitcoin signing.

Keystone Pro 3: airgap HW wallet with QR + microSD, color touchscreen, multi-currency support, fingerprint auth. USE WHEN: integrating Keystone, evaluating mid-priced HW options.

Krux: DIY airgap signer running on Sipeed M5StickV / Maix Amigo. Open-source, multi-language, stateless. USE WHEN: integrating Krux, evaluating M5StickV-based signers.

Ledger hardware wallets: Nano S Plus, Nano X, Stax, Flex. BOLOS app architecture, Ledger Live, secure element, anti-klepto. USE WHEN: integrating with Ledger, supporting Ledger in app, debugging PSBT signing or HW Recovery service issues.

Multi-vendor multisig: combining HW wallets from different vendors (Trezor + Ledger + Coldcard) for diversification. Coordinator-mediated setup, descriptor sharing, threat model. USE WHEN: designing multi-vendor custody, implementing 2-of-3 multisig with diverse hardware.

Foundation Passport: QR-only airgap HW wallet. No USB connectivity for signing. Camera + microSD only. Open-source firmware. USE WHEN: integrating Passport, designing strict airgap flows.

PSBT signing flow patterns across HW vendors: USB direct, microSD airgap, QR airgap, NFC, multi-device coordination. USE WHEN: designing HW signing UX, debugging cross-device PSBT flow, supporting multi-vendor multisig.

SeedSigner: DIY Bitcoin signing device. Raspberry Pi Zero + camera + screen. Boots from microSD, no permanent state. Stateless airgap signing. USE WHEN: building / supporting SeedSigner, designing stateless signing flows.

Specter DIY: open-source HW wallet built on STM32 dev board with display. By the Specter team. USE WHEN: building Specter DIY, evaluating DIY HW signing options.

Trezor hardware wallets: Model T, Model One, Trezor Safe 3, Safe 5. Trezor Suite, trezorctl, USB protocol, BIP32 derivation, passphrase support, Shamir Backup. USE WHEN: integrating with Trezor, supporting Trezor in app, troubleshooting Trezor signing.

BlueWallet: mobile Bitcoin + Lightning wallet (iOS/Android). LND on-device + LndHub backend variants. Multi-wallet support. USE WHEN: mobile wallet integrations, evaluating BlueWallet vs Phoenix / Mutiny.

BTCPay Server: open-source merchant payment processor. Self-hosted, supports BTC + Lightning + altcoins, plugin ecosystem, Lightning Address resolver, point-of-sale. USE WHEN: deploying merchant payments, integrating with BTCPay, building plugins.

Caravan: open-source web-based multisig coordinator (no install). Read-only by default; HW wallet support via HWI bridge. USE WHEN: setting up multisig without installing software, educational multisig flows.

Electrs: Romanmandryk's Electrum-protocol indexer in Rust. Lightweight, serves Electrum clients + LN nodes (filter-based scan). USE WHEN: deploying personal Electrum server, integrating LN with Electrum backend, evaluating indexers.

Electrum Wallet: classic Python desktop wallet. Lightweight, runs on most platforms, plugin ecosystem, hardware wallet support. USE WHEN: evaluating mature Bitcoin wallet, integrating Electrum protocol clients.

Esplora: Blockstream's HTTP-based block explorer + indexer. REST API at /api/<endpoint>. Powers blockstream.info, mempool.space's earlier versions, and self-hosted explorers. USE WHEN: deploying a personal block explorer, integrating with Esplora REST API, building wallet / monitoring on Esplora-style endpoint.

Fulcrum: cppbtc-team Electrum-protocol indexer in C++. Faster than electrs for high-volume queries. Serves Electrum clients + LN nodes. USE WHEN: deploying high-load Electrum server, comparing with electrs.