pytest-django integration testing specialist. Covers all fixtures (db, transactional_db, client, rf, settings, mailoutbox, django_user_model), @pytest.mark.django_db options, DRF APIClient, factory_boy integration, async views, signals, management commands, and multi-database testing. USE WHEN: user mentions "pytest-django", "django test", "@pytest.mark.django_db", asks about "django client fixture", "DRF APIClient", "django signals test", "management command test", "django async view test". DO NOT USE FOR: Non-Django Python tests - use `pytest` or `python-integration`; FastAPI - use `fastapi-testing`; Pure container setup - use `testcontainers-python`

Spring Cloud Gateway for API routing, filtering, and load balancing. Covers route predicates, filters, rate limiting, and circuit breaker integration. USE WHEN: user mentions "spring cloud gateway", "API gateway", "route predicates", "gateway filters", "rate limiting gateway", "load balancing gateway" DO NOT USE FOR: simple reverse proxy - use nginx, Zuul (deprecated) - use Spring Cloud Gateway instead

Spring Data JPA for database access in Spring Boot applications. Covers repositories, entities, relationships, queries, pagination, and auditing. Based on production patterns from castellino and gestionale-presenze projects. USE WHEN: user mentions "JPA", "repository", "entity", "database queries", asks about "pagination", "Criteria API", "Specifications", "@Query", "relationships" DO NOT USE FOR: Spring Boot basics (use `spring-boot`), Spring Security (use `spring-security`), MongoDB (use `mongodb-expert`), SQL-only tasks (use `sql-expert`)

Spring Data MongoDB for Java/Spring Boot applications. Covers repositories, MongoTemplate, aggregations, and document mapping. USE WHEN: user mentions "spring data mongodb", "MongoTemplate", "MongoRepository", "@Document", "Spring Boot MongoDB", "aggregation pipeline Java" DO NOT USE FOR: raw MongoDB driver - use `mongodb` instead, relational databases - use `spring-data-jpa` or `spring-data-jdbc` instead

Pinecone's Canopy framework — a pre-packaged RAG stack on top of Pinecone. Covers Canopy CLI, REST server (OpenAI-compatible), chunking, embedding, retrieval, chat-history management, and customization hooks (custom chunkers/records). USE WHEN: user mentions "Canopy", "Pinecone Canopy", "canopy start", "canopy new", "Pinecone out-of-the-box RAG" DO NOT USE FOR: custom pipelines on non-Pinecone stores - use `rag-architecture`; Postgres-based stacks - use `r2r`; LangChain/LlamaIndex abstractions - use `langgraph-rag`/`llamaindex`

esbuild extremely fast JavaScript bundler. Used internally by Vite. Use for simple bundling, library builds, or understanding Vite internals. USE WHEN: user mentions "esbuild", "fast bundler", asks about "esbuild config", "library bundling", "esbuild API" DO NOT USE FOR: Complex apps (use Vite), Webpack projects (use webpack skill), need extensive plugins (use Rollup/Webpack)

factory_boy test data generation specialist. Covers Factory, DjangoModelFactory, SQLAlchemyModelFactory, all field declarations (Faker, LazyAttribute, Sequence, SubFactory, RelatedFactory, post_generation, Trait, Maybe, Dict, List), batch creation, pytest integration, and Celery task testing patterns. USE WHEN: user mentions "factory_boy", "test factory", "DjangoModelFactory", "SQLAlchemyModelFactory", asks about "test data generation", "factory traits", "SubFactory", "factory fixtures". DO NOT USE FOR: pytest internals - use `pytest`; Django setup - use `pytest-django`; Hypothesis property testing - use `pytest` with Hypothesis

Flyway database migrations for Spring Boot applications. Covers migration scripts, versioning, callbacks, and rollback strategies. Based on production patterns from castellino and gestionale-presenze projects. USE WHEN: user mentions "flyway", "database versioning", "Java migrations", "Spring Boot migrations", "V1__", "migration checksum" DO NOT USE FOR: general migration strategies - use `migrations` instead, Liquibase - use specific tool skill, Prisma/TypeORM - use respective skills

JavaScript language fundamentals. Covers ES6+, modules, async patterns. Use when working with plain JS projects without TypeScript. USE WHEN: user mentions "javascript", "ES6", "async/await", "promises", "modules", asks about "destructuring", "spread operator", "arrow functions", "ESM vs CommonJS" DO NOT USE FOR: TypeScript projects - use `typescript` skill instead DO NOT USE FOR: Node.js runtime - use `nodejs` skill instead DO NOT USE FOR: Browser APIs - use framework-specific skills

LanceDB columnar vector database. Arrow-native storage, versioning and time-travel, merge-on-read, full-text + vector hybrid, pandas/polars integration, object-storage backing, Rust-based performance, embedding function registration, IVF_PQ and HNSW indexes. USE WHEN: user mentions "LanceDB", "Lance format", "Arrow vector store", "embedded vector DB", "pylance", "lance time travel" DO NOT USE FOR: managed vector DBs - use `vector-stores/pinecone-advanced`, `vector-stores/mongodb-atlas-vector`; distributed Milvus - use `vector-stores/milvus`

Project Lombok for reducing Java boilerplate. Covers annotations for getters, setters, constructors, builders, logging, and more. Based on production patterns from castellino and gestionale-presenze projects. USE WHEN: user mentions "lombok", "@Data", "@Builder", "@Slf4j", asks about "boilerplate reduction", "getters/setters", "@RequiredArgsConstructor", "@Value" DO NOT USE FOR: Java language features - use `java` skill instead DO NOT USE FOR: MapStruct integration - use `mapstruct` skill DO NOT USE FOR: Spring annotations - use `backend-spring-boot` skill

Node.js performance profiling with V8 CPU profiler, heap analysis, and perf_hooks. Use for identifying bottlenecks and memory leaks. USE WHEN: user mentions "Node.js performance", "profiling", "memory leak", asks about "V8 profiler", "heap snapshot", "CPU profile", "perf_hooks", "event loop lag", "Node.js optimization" DO NOT USE FOR: Java/Python profiling - use respective skills instead

Python data processing with pandas, openpyxl, and lxml. Covers DataFrame operations, Excel I/O, XML parsing, bulk data transformation, and large-file handling. Use when processing tabular data, spreadsheets, or XML in Python. USE WHEN: user mentions "pandas", "DataFrame", "openpyxl", "read_excel", "lxml", "XPath", "CSV processing", "Excel parsing", "bulk data", "large file", "data transformation", "UTF-16", "codecs" DO NOT USE FOR: SQL databases (use sql-expert), NumPy-only math, ML/training

Python integration testing orchestration skill. Covers test pyramid strategy, conftest.py architecture, pytest markers for integration tests, GitHub Actions CI/CD integration, parallel execution with pytest-xdist, and test isolation patterns. USE WHEN: user mentions "python integration test", "integration test strategy", "conftest architecture", "CI integration tests", asks about test pyramid, or needs to set up integration testing infrastructure in Python. DO NOT USE FOR: Unit tests - use `pytest`; Django-specific - use `pytest-django`; FastAPI-specific - use `fastapi-testing`; Container setup - use `testcontainers-python`

Rust code quality with Clippy, rustfmt, and cargo tools. Covers linting, formatting, and idiomatic Rust patterns. USE WHEN: user works with "Rust", "Cargo", "Actix", "Axum", asks about "Clippy", "rustfmt", "Rust linting", "Rust best practices", "idiomatic Rust" DO NOT USE FOR: SonarQube - use `sonarqube` skill, security - use `rust-security` skill

Automatic type generation from OpenAPI and GraphQL schemas. Covers openapi-typescript, graphql-codegen, and contract sync. USE WHEN: user asks about "openapi-typescript", "graphql-codegen", "generate types from API", "type generation", "API types", "schema to TypeScript" DO NOT USE FOR: manual type definitions - use TypeScript skills, contract validation - use `openapi-contract` skill

FastAPI integration testing specialist. Covers synchronous TestClient, async httpx AsyncClient, dependency injection overrides, auth testing (JWT, OAuth2, API keys), WebSocket testing, file uploads, background tasks, middleware testing, and HTTP mocking with respx, responses, and pytest-httpserver. USE WHEN: user mentions "FastAPI test", "TestClient", "httpx async test", "dependency override test", "respx mock", asks about testing FastAPI endpoints, authentication in tests, or HTTP client mocking. DO NOT USE FOR: Django - use `pytest-django`; pytest internals - use `pytest`; Container infrastructure - use `testcontainers-python`

R2R (RAG to Riches) by SciPhi — a production-ready RAG engine with built-in hybrid search, automatic knowledge graph construction, agentic workflows, multi-tenant support, REST + Python SDK, and self-hosted or cloud deployment. USE WHEN: user mentions "R2R", "RAG to Riches", "SciPhi", "R2R SDK", "R2R knowledge graph", "R2R ingestion pipeline" DO NOT USE FOR: DIY retrieval pipelines - use `rag-architecture`; Pinecone-specific stacks - use `canopy`; lightweight embeddings on edge - use `txtai`

Spring Boot integration testing with Testcontainers, sliced tests, and full context. Covers real database testing, API integration, and end-to-end flows. USE WHEN: user mentions "spring integration test", "testcontainers spring", "full context test", asks about "@SpringBootTest webEnvironment", "integration test database", "API integration test" DO NOT USE FOR: Unit tests - use `junit`; Slice tests only - use `spring-boot-test`; REST client testing - use `rest-assured`; E2E browser tests - use Selenium

Spring Cloud Config for centralized configuration management in microservices. Covers Config Server, Config Client, Git backend, and dynamic refresh. USE WHEN: user mentions "spring cloud config", "config server", "centralized configuration", "@RefreshScope", "externalized config" DO NOT USE FOR: simple properties files - use standard Spring Boot, secrets management - combine with Vault

testcontainers-python specialist. Covers all container modules (PostgreSQL, MySQL, MongoDB, Redis, Kafka, RabbitMQ, MinIO, Elasticsearch, LocalStack), GenericContainer, wait strategies, Docker Compose, networks, pytest fixtures, and CI/CD integration. USE WHEN: user mentions "testcontainers", "docker in tests", "real database in tests", "test with real postgres/redis/kafka", asks about container fixtures or Docker-based testing. DO NOT USE FOR: Spring Boot testcontainers (Java) - use `spring-boot-integration`; Mocking HTTP - use `fastapi-testing`; Pure pytest patterns - use `pytest`

Anthropic Python SDK for Claude API integration. Covers messages API, streaming, tool use, vision, error handling, and best practices. Use when building Python applications that call the Claude API. USE WHEN: user mentions "anthropic", "claude api", "anthropic sdk", "anthropic.Anthropic()", "client.messages.create", "claude-opus", "claude-sonnet", "tool_use", "streaming claude", "claude python" DO NOT USE FOR: OpenAI API, other LLM providers, JavaScript/TypeScript Anthropic SDK

ASP.NET Core 8+ with controllers, services, DI, configuration, and middleware pipeline. Covers Program.cs setup and enterprise patterns. USE WHEN: user mentions "ASP.NET Core", "Web API", ".NET controllers", "Program.cs", "dependency injection", ".NET DI", ".NET configuration", "appsettings" DO NOT USE FOR: Minimal APIs (use `aspnet-minimal-api`), Spring Boot (use `spring-boot`), NestJS (use `nestjs`), Express (use `express`)

Secrets and credentials management. Covers environment variables, secret stores, rotation policies, and detection of leaked secrets. USE WHEN: user mentions "secrets", "credentials", "API keys", "environment variables", ".env", asks about "secret leaks", "vault", "secret rotation", "gitleaks", "secret detection" DO NOT USE FOR: OWASP vulnerabilities - use `owasp-top-10`, supply chain - use `supply-chain`, general security - use `owasp`

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/DevOps skills

LangChain framework for LLM application development. Covers chains, agents, tools, RAG pipelines, vector stores, memory, and LangChain Expression Language (LCEL). Python and TypeScript/JavaScript. USE WHEN: user mentions "langchain", "LLM chain", "AI agent", "LCEL", "retrieval chain", "LangChain tools", "LangSmith", "LangGraph" DO NOT USE FOR: direct API calls without framework - use Claude/OpenAI SDK; vector database specifics - use `vector-databases`; RAG architecture patterns - use `rag-patterns`

Logback - flexible and powerful logging framework for Java and Spring Boot applications. Successor to Log4j with native SLF4J support, async logging, and automatic file rotation. USE WHEN: user mentions "logback", "spring boot logging", "java logging configuration", asks about "logback-spring.xml", "rolling file appender", "async logging in java" DO NOT USE FOR: SLF4J API usage - use `slf4j` instead, Log4j2 - use separate Log4j2 skill, Node.js logging - use `winston` or `pino` instead, Python logging - use `python-logging` instead

SLF4J - Simple Logging Facade for Java. Standard logging API that abstracts underlying implementation (Logback, Log4j2). Provides parameterized logging and MDC support. USE WHEN: user mentions "slf4j", "java logging api", "parameterized logging", asks about "how to log in Java", "logger facade", "MDC in java", "logging best practices java" DO NOT USE FOR: Logback configuration - use `logback` instead, Log4j2 configuration - use Log4j2 skill, Node.js logging - use `winston` or `pino` instead, Python logging - use `python-logging` instead

structlog - structured logging library for Python with native JSON support, context binding, and processor pipeline. Integrates with FastAPI, Django, and standard logging module. USE WHEN: user mentions "structlog", "python structured logging", "context binding", asks about "JSON logging python", "fastapi logging", "django structured logging" DO NOT USE FOR: Standard Python logging - use `python-logging` instead, Node.js logging - use `pino` or `winston`, Java logging - use `slf4j` or `logback` instead

C# 12 language features including records, pattern matching, nullable reference types, LINQ, async/await, and modern language patterns. USE WHEN: user mentions "C#", "C# records", "pattern matching", "LINQ", "async/await", "nullable reference types", "C# generics", "C# language features" DO NOT USE FOR: TypeScript - use `typescript`, Java - use Java skills, F# or VB.NET specific features

Data-intensive / data-platform architecture: warehouse vs lakehouse, OLTP vs OLAP, batch vs streaming (lambda/kappa), change-data-capture, and data mesh. Architect-level platform-shape decisions, not SQL or ETL code. USE WHEN: designing a data platform/pipeline architecture, "data warehouse", "lakehouse", "OLAP vs OLTP", "lambda/kappa", "streaming vs batch", "CDC", "data mesh", "medallion", analytics platform, columnar store, ingestion topology. DO NOT USE FOR: writing SQL/ORM (use database skills); a specific ETL tool (use data/data-processing skills); storage-engine internals (use `storage-engines`).

Distributed-systems architecture at the protocol level: consensus (Raft, Paxos, BFT), replication and quorums, consistency models, clock synchronization, and the CAP/PACELC trade-offs. Architect-level — how to make state agree and survive failures. USE WHEN: designing replicated/consensus systems, "Raft", "Paxos", "BFT", "quorum", "leader election", "consistency model", "linearizability", "CAP", "PACELC", "split-brain", replication topology, distributed state machines. DO NOT USE FOR: app microservice wiring (use web/enterprise patterns); message queues (use messaging skills); blockchain specifics (use bitcoin skills).

Entity Framework Core with DbContext, migrations, LINQ queries, relationships, and performance optimization. Covers EF Core 8+ patterns. USE WHEN: user mentions "Entity Framework", "EF Core", "DbContext", "migrations", "LINQ", "EF relationships", "database first", "code first" DO NOT USE FOR: Prisma - use `prisma`, Drizzle - use `drizzle`, Spring Data JPA - use `spring-data-jpa`, Dapper (raw SQL)

ETL/ELT data pipeline patterns. Extract from APIs/databases, transform with streaming or batch, load to data warehouses. Node.js streams, Python pandas/Polars, Apache Airflow DAGs, and database-native ELT. USE WHEN: user mentions "ETL", "ELT", "data pipeline", "data ingestion", "Airflow", "data warehouse", "batch processing", "data migration" DO NOT USE FOR: real-time event streaming - use messaging skills; data export to CSV/Excel - use `data-export`

OpenAPI Generator - generate clients and servers from OpenAPI specs USE WHEN: user mentions "OpenAPI Generator CLI", "generate Java client", "generate Spring server", "openapi-generator-cli", "openapi-generator-maven-plugin", asks about "generate server from OpenAPI", "OpenAPI Generator templates" DO NOT USE FOR: TypeScript-only generation - use `openapi-codegen` instead; Writing OpenAPI specs - use `openapi` instead; GraphQL - use `graphql-codegen` instead

Pino - extremely fast and low overhead Node.js logger with JSON-native structured logging. 10x faster than Winston. Optimized for high-performance APIs and production environments. USE WHEN: user mentions "pino", "fast logging", "high performance logging", "fastify logging", asks about "fastest node.js logger", "JSON structured logging", "low overhead logging" DO NOT USE FOR: Winston logging - use `winston` instead, Python logging - use `python-logging` instead, Complex transport requirements - use `winston` instead

Winston - versatile logging library for Node.js with multiple transports, custom formatting, and log rotation. Supports structured logging, custom levels, and enterprise integration. USE WHEN: user mentions "winston", "node.js logging", "multiple transports", "log rotation", asks about "how to log to multiple destinations", "rotate log files in Node.js", "custom log formats" DO NOT USE FOR: Pino logging - use `pino` instead, Python logging - use `python-logging` instead, Java logging - use `slf4j` or `logback` instead

API gateway patterns and implementations. Kong, AWS API Gateway, NGINX as gateway, rate limiting, request routing, authentication offloading, and request/response transformation. USE WHEN: user mentions "API gateway", "Kong", "AWS API Gateway", "NGINX gateway", "gateway pattern", "request routing", "BFF" DO NOT USE FOR: reverse proxy basics - use infrastructure skills; service mesh - use `service-mesh`; rate limiting in app - use `rate-limiting`

AWS SDK integration for Node.js (v3) and Python (boto3). Core services: S3, Lambda, DynamoDB, SQS, SNS, CloudWatch, IAM. Configuration, credentials, and production patterns. USE WHEN: user mentions "AWS", "Amazon Web Services", "Lambda", "DynamoDB", "SQS", "SNS", "CloudWatch", "IAM", "boto3", "aws-sdk" DO NOT USE FOR: S3 file operations - use `cloud-storage`; SQS messaging patterns - use `sqs`; Azure/GCP - use respective skills

Axios - promise-based HTTP client for browser and Node.js USE WHEN: user mentions "Axios", "HTTP requests", "API calls", "interceptors", "Axios instance", asks about "how to make HTTP calls", "configure Axios", "add auth header", "handle HTTP errors" DO NOT USE FOR: Fetch API - use `http-clients` instead; ky/ofetch - use `http-clients` instead; GraphQL clients - use `graphql-codegen` instead; tRPC - use `trpc` instead

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.

Bitcoin P2P network protocol: messages, version handshake, addr/addrv2, compact blocks (BIP152), compact block filters (BIP157/158), v2 transport encryption (BIP324), wtxid relay (BIP339), Erlay (BIP330), Dandelion++ (BIP156). USE WHEN: implementing/debugging a node, integrating with bitcoind P2P, understanding address gossip, designing privacy-preserving propagation.

Contract testing for API consumers and providers. Pact framework, Spring Cloud Contract, consumer-driven contracts, provider verification, and contract broker setup. USE WHEN: user mentions "contract testing", "Pact", "consumer-driven contract", "Spring Cloud Contract", "API contract", "provider verification" DO NOT USE FOR: OpenAPI validation - use `openapi-contract`; integration testing - use integration test skills

Google Cloud Platform SDK integration. Cloud Functions, Firestore, Cloud Storage, Pub/Sub, BigQuery, and Cloud Run. Node.js and Python client libraries. USE WHEN: user mentions "GCP", "Google Cloud", "Cloud Functions", "Firestore", "Cloud Storage", "Pub/Sub", "BigQuery", "Cloud Run", "Firebase" DO NOT USE FOR: AWS services - use `aws`; Azure services - use `azure`; Firebase Auth - use auth skills

gRPC service development. Protocol Buffers (protobuf), service definitions, streaming (unary, server, client, bidirectional), interceptors, and code generation for Node.js, Go, Java, and Python. USE WHEN: user mentions "gRPC", "protobuf", "Protocol Buffers", ".proto", "grpc-js", "tonic", "grpc-java", "service mesh RPC" DO NOT USE FOR: REST APIs - use `rest-api`; GraphQL - use `graphql`; WebSocket - use real-time skills

Hybrid edge-cloud AI architecture: local-first inference with cloud escalation, model cascading, and splitting the workload across device and datacenter to balance latency, cost, privacy, and quality. Architect-level topology. USE WHEN: designing systems that combine on-device and cloud AI, "local-first", "cloud fallback", "model cascade", "escalation", "hybrid inference", routing by confidence/complexity, edge+cloud trade-offs. DO NOT USE FOR: pure on-device (use `edge-inference`); pure cloud serving (use `inference-serving-topology`); multi-provider API routing (use `model-gateway-routing`).

Background job queue systems. BullMQ (Node.js), Celery (Python), Sidekiq (Ruby), Spring Batch. Job scheduling, retries, priorities, concurrency control, and dead letter queues. USE WHEN: user mentions "job queue", "background job", "BullMQ", "Bull", "Celery", "worker", "async task", "task queue", "Sidekiq" DO NOT USE FOR: cron scheduling without queue - use `cron-scheduling`; message brokers - use messaging skills (Kafka, RabbitMQ)

JUnit 5 testing framework with Mockito integration. Covers unit tests, mocking, and Spring Boot test integration. USE WHEN: user mentions "junit", "java test", "mockito", asks about "@Test", "@Mock", "@InjectMocks", "unit test java", "spring boot test" DO NOT USE FOR: Integration tests with containers - use `testcontainers`; REST API tests - use `rest-assured`; E2E tests - use Selenium; JavaScript/TypeScript - use `vitest` or `jest`

Rate limiting and throttling. Token bucket, sliding window, fixed window algorithms. Express rate limit, Spring rate limiting, Redis-based distributed rate limiting, and API quota management. USE WHEN: user mentions "rate limit", "throttle", "API quota", "too many requests", "429", "express-rate-limit", "sliding window", "token bucket" DO NOT USE FOR: circuit breaker patterns - use `resilience-patterns`; DDoS protection - use infrastructure/WAF solutions

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`

Serverless computing patterns. AWS Lambda, Azure Functions, GCP Cloud Functions. Deployment frameworks: Serverless Framework, AWS SAM, SST. Cold starts, event sources, and production optimization. USE WHEN: user mentions "serverless", "Lambda", "cloud function", "Azure Functions", "SAM", "SST", "Serverless Framework", "cold start", "FaaS" DO NOT USE FOR: container orchestration - use `kubernetes` or `docker`; always-on servers - use backend framework skills

Service mesh patterns and implementations. Istio, Linkerd, traffic management, mutual TLS, observability, circuit breaking, and canary routing at the infrastructure level. USE WHEN: user mentions "service mesh", "Istio", "Linkerd", "sidecar proxy", "mutual TLS", "mTLS", "traffic splitting", "Envoy", "mesh" DO NOT USE FOR: API gateway patterns - use `api-gateway`; in-app resilience - use `resilience-patterns`; Kubernetes basics - use `kubernetes`

Server-Sent Events for real-time server-to-client streaming. Express, Fastify, FastAPI, Spring WebFlux SSE implementations. Event streams, reconnection, and EventSource API. USE WHEN: user mentions "SSE", "Server-Sent Events", "EventSource", "event stream", "text/event-stream", "live feed", "streaming updates" DO NOT USE FOR: bidirectional communication - use `socket-io`; WebRTC - use `webrtc`; LLM streaming - use AI SDK skills

Angular HttpClient with interceptors, error handling, retry, and caching patterns. Covers functional interceptors and typed responses. USE WHEN: user mentions "HttpClient", "Angular HTTP", "interceptors", "API calls", "Angular REST", "HTTP error handling", "auth interceptor" DO NOT USE FOR: Axios - use `axios` skill, Fetch API directly, backend HTTP frameworks

Apache POI for Excel file manipulation in Java applications. USE WHEN: user mentions "Apache POI", "Excel generation", asks about "Java Excel", "XLSX export", "Excel import", "POI workbook", "spreadsheet generation" DO NOT USE FOR: CSV files - use OpenCSV or standard Java CSV libraries

ASP.NET Core Identity for authentication, roles, claims, and external providers. Covers Identity setup, customization, and token-based auth. USE WHEN: user mentions "ASP.NET Identity", "user authentication", ".NET auth", "roles and claims", "Identity scaffolding", "external login providers" DO NOT USE FOR: JWT-only auth without Identity, Spring Security - use `spring-security`

ASP.NET Core custom middleware, pipeline order, exception handling middleware, and request/response manipulation. USE WHEN: user mentions "middleware", "request pipeline", "exception middleware", "ASP.NET middleware", "UseMiddleware", "pipeline order" DO NOT USE FOR: Express middleware - use `express`, NestJS middleware - use `nestjs`

ASP.NET Core Minimal API endpoints, route groups, filters, and typed results. Covers modern .NET 8+ endpoint patterns. USE WHEN: user mentions "Minimal API", "MapGet", "MapPost", "route groups", "endpoint filters", ".NET minimal", "lambda endpoints" DO NOT USE FOR: Controller-based APIs (use `aspnet-core`), Express.js (use `express`), FastAPI (use `fastapi`)

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.

Cron and scheduled task management. node-cron, cron expressions, Spring @Scheduled, APScheduler (Python), and distributed scheduling patterns. USE WHEN: user mentions "cron", "scheduled task", "cron job", "node-cron", "@Scheduled", "APScheduler", "periodic task", "crontab" DO NOT USE FOR: job queues with workers - use `job-queues`; one-off delayed tasks - use `job-queues`

Data export to CSV, Excel (XLSX), and JSON. ExcelJS, SheetJS (xlsx), Papa Parse, Apache POI (Java), openpyxl (Python). Streaming exports for large datasets. USE WHEN: user mentions "export CSV", "export Excel", "XLSX generation", "download spreadsheet", "ExcelJS", "SheetJS", "Papa Parse", "data export" DO NOT USE FOR: PDF generation - use `pdf-generation`; file upload/download - use `file-upload`/`cloud-storage`

JaCoCo Java code coverage tool USE WHEN: user mentions "JaCoCo", "Java coverage", "code coverage", asks about "coverage threshold", "jacoco-maven-plugin", "coverage report", "LINE coverage", "BRANCH coverage" DO NOT USE FOR: JavaScript/TypeScript coverage - use Vitest skill, SonarQube analysis - use `sonarqube` skill, test execution - use testing skills

JSDoc - documentation generator for JavaScript with type annotations. USE WHEN: user mentions "JSDoc", "JavaScript documentation", asks about "documenting JavaScript", "type hints", "jsdoc comments", "API documentation generation" DO NOT USE FOR: TypeScript - use `jsdoc-tsdoc` skill for TypeScript/TSDoc

Core Lightning (CLN, formerly c-lightning) by Blockstream: lightningd, lightning-cli, plugin architecture (Python pyln-client, Rust cln-plugin, Go glightning), commando, BOLT12 leadership. USE WHEN: integrating with CLN, writing plugins, debugging CLN-specific behaviour, leveraging BOLT12 features.

LDK (Lightning Dev Kit) by Lightning Labs: modular Rust crates for building custom Lightning apps. ldk-node for opinionated quick-start. ChannelManager, ChainMonitor, Router, async signer, persistence. USE WHEN: embedding Lightning into mobile/desktop apps, building custom Lightning logic, scaling beyond LND-style daemon.

Phoenixd by ACINQ: headless server build of Phoenix wallet for self-hosting. Single-node Lightning daemon with batteries-included ACINQ swap-in / swap-out, BOLT12 receive, WebSocket payments API. USE WHEN: deploying a self-hosted minimal Lightning daemon for a service (point-of-sale, donation page, micro-merchant), avoiding full LND/CLN complexity.

REST Assured Java library for testing REST APIs. Covers HTTP requests, JSON/XML validation, and Spring Boot integration. USE WHEN: user mentions "rest assured", "api test java", "rest api test", asks about "given when then", "RestAssured", "HTTP test", "JSON validation" DO NOT USE FOR: Unit tests - use `junit`; E2E browser tests - use Selenium; WebSocket testing - use dedicated tools; Non-Java projects - use language-specific HTTP clients

Socket.IO real-time bidirectional communication. Rooms, namespaces, acknowledgments, middleware, scaling with Redis adapter, and TypeScript types. USE WHEN: user mentions "Socket.IO", "socket.io", "real-time chat", "live updates", "bidirectional WebSocket", "rooms", "namespaces" DO NOT USE FOR: SSE (server-sent events) - use `sse`; WebRTC - use `webrtc`; raw WebSocket without Socket.IO - use framework WS skills

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 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.

Greenlight by Blockstream: hosted CLN with self-custodial signing. Server runs the full CLN node; user retains private keys via signer protocol. Mobile-friendly without running a full LN node. USE WHEN: building mobile/web LN apps with self-custody but no on-device daemon, integrating with Blockstream's hosted infra.

LND (Lightning Network Daemon) by Lightning Labs: gRPC + REST API, macaroons, lncli, autopilot, channel backups (SCB), Tor support, watchtowers, integration with bitcoind/btcd/Neutrino backend. USE WHEN: integrating with LND, scripting lncli, debugging LND-specific issues, designing LND-based services.

LSP (Lightning Service Provider) specifications: BLIPs, JIT channels, on-pay channel open, MPP-trampoline, BOLT12 hosted invoice. Major LSPs: ACINQ (Phoenix backend), Voltage, Olympus, Megalith, Flashsats. USE WHEN: integrating with an LSP, designing LSP services, evaluating LSP options for a wallet.

WebLN: browser API for Lightning. window.webln exposed by wallet extensions / mobile webviews. Methods: enable, getInfo, sendPayment, makeInvoice, signMessage. Bitcoin Connect (modern wrapper). USE WHEN: building web apps with Lightning payments, integrating with Alby/getalby, designing WebLN-compatible flows.

SQL Server and Azure SQL Database with T-SQL, indexes, stored procedures, and performance optimization patterns. USE WHEN: user mentions "SQL Server", "T-SQL", "MSSQL", "Azure SQL", "SQL Server indexes", "stored procedures", "SQL Server performance" DO NOT USE FOR: PostgreSQL - use `postgresql`, MySQL - use `mysql`, MongoDB - use `mongodb`

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.

RGB protocol: client-side validated smart contracts on Bitcoin + Lightning. Schema-driven contracts, AluVM (RGB VM), rgb-lightning-node for LN integration. USDT-on-RGB rollout. USE WHEN: building RGB contracts, integrating RGB Lightning, comparing with TAP.

Bitcoin Dev Kit (BDK): high-level Rust wallet library. Descriptor-based wallets, multiple chain backends (Esplora, Electrum, RPC), PSBT, fee estimation, coin selection. Bindings to Swift / Kotlin / Python / Flutter. USE WHEN: building wallets in Rust or via BDK bindings, integrating descriptor wallets into apps.

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.

Eclair Lightning implementation by ACINQ: Scala/Akka, eclair-cli, plugin system, primarily backend service. Powers Phoenix wallet's server side and ACINQ's main routing node. USE WHEN: deploying Eclair as backend, integrating with ACINQ's Phoenix backend, evaluating Scala/JVM Lightning options.

# API Security Skill

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.

mempool.space: open-source mempool explorer + accelerator. Detailed fee tracking, mempool blocks projection, REST + WebSocket APIs. Self-hostable. USE WHEN: integrating mempool.space API, deploying self-hosted variant, evaluating fee estimation services.

Self-hosted Bitcoin node distros: Umbrel, Start9 Embassy, RaspiBlitz, MyNode, Citadel. Pre-configured Bitcoin + Lightning + apps. USE WHEN: deploying personal node infrastructure, choosing between distros.

rust-miniscript: Rust crate for Miniscript and descriptor handling. Policy compilation, satisfaction analysis, descriptor parsing for legacy + Tapscript. USE WHEN: working with descriptors / miniscript in Rust, building wallets that compose spending conditions.

rust-bitcoin: Rust crate for Bitcoin primitives. Tx, Block, Script, Address, Network, key types, PSBT, BIP32. Foundation for BDK, LDK, miniscript-rs. USE WHEN: building Bitcoin apps in Rust, parsing/constructing txs, working with addresses + scripts.

Bitcoin over Tor: Tor v3 hidden services, onion-only nodes, bitcoind torcontrol integration, Lightning over Tor. USE WHEN: hardening node privacy, configuring onion-only setups, debugging Tor + bitcoind interaction.

Fuzz testing for Bitcoin code: Bitcoin Core's libFuzzer harnesses, rust-bitcoin / bdk / secp256k1 cargo-fuzz, AFL++. Seed corpus bootstrapping, regression tests. USE WHEN: hardening Bitcoin libraries, writing fuzz harnesses, reproducing fuzz-found crashes.

Property-based testing: proptest / quickcheck (Rust), hypothesis (Python). Strategies for tx serialization, descriptor round-trip, miniscript satisfaction. USE WHEN: testing Bitcoin parsers, ensuring round-trip invariants, catching edge cases beyond example tests.

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.

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.

bdkpython: Python bindings to BDK. Same descriptor-first wallet API as Rust BDK. UniFFI-generated. USE WHEN: building Python wallets with BDK quality, multi-language app where Python integrates same logic as Rust/Swift.

bitcoinj: mature Java/Kotlin Bitcoin library. SPV node, wallet, HD derivation, used by BlueWallet (Android), older mobile wallets. USE WHEN: building JVM Bitcoin apps, Android-native wallet code.

bitcoinjs-lib: TypeScript/JavaScript Bitcoin library. Tx, Script, Address, key types, PSBT, BIP32. Browser + Node. USE WHEN: building Bitcoin apps in JS/TS, server or browser.

btcd: full-node Bitcoin implementation in Go by btcsuite. Server, RPC, wallet (btcwallet), Lightning (LND-derived). USE WHEN: building Go-native Bitcoin services, alternative to bitcoind, integrating with btcsuite ecosystem.

Lightning Dev Kit (LDK): modular Rust crates for embedding Lightning in apps. ldk-node for opinionated quick-start. Bindings to Swift / Kotlin / JS. USE WHEN: embedding Lightning in mobile/desktop apps, building custom LN logic.