A comprehensive collection of 30+ Claude Code skills for cold email and outbound sales, covering strategy, infrastructure, lead sourcing, and copywriting, with a guided kickoff flow and signal playbooks.

Mint a tamper-evident, post-quantum-signed receipt for a consequential agent action (deploy, delete, pay, grant-access, model decision) so it can be verified later from the certificate alone. Use when an autonomous agent takes a side-effecting action that may need to be proven later, or when satisfying EU AI Act Article 12 record-keeping. Three decisions: whether an action needs a receipt, minting it, verifying it. Signing is delegated to the open-source OpenAgentOntology package. Not after-the-fact log analysis; not a hosted notary; not a legal opinion.

PDF library for Go: layout engine, HTML to PDF, forms, signatures, barcodes, and PDF/A. Apache 2.0.

Invoicerr is a freelance-focused invoicing app that lets you create quotes, generate invoices, track payments, and collect secure signatures.

Cross-platform PDF digital signing tool. JavaFX desktop UI with drag-to-place visible signatures, PKCS#11/PKCS#12 keystores, RFC 3161 timestamping, OCSP/CRL long-term validation, and a scriptable CLI.

Data Sovereign Email Signatures and Out-of-Office Replies. Unified Outlook branding everywhere – with zero external data exposure.

PDF editor in the browser – add text, checkboxes, pictures, signatures to PDF files. Merge, rotate PDF pages – iframe, script and React component

A collection of webhook integration skills for AI coding agents, providing step-by-step guidance and code for receiving, verifying, and handling webhooks from providers like Stripe, Shopify, and GitHub.

Golang data structures — slices (internals, capacity growth, preallocation, slices package), maps (internals, hash buckets, maps package), arrays, container/list/heap/ring, strings.Builder vs bytes.Buffer, generic collections, pointers (unsafe.Pointer, weak.Pointer), and copy semantics. Use when choosing or optimizing Go data structures, implementing generic containers, using container/ packages, unsafe or weak pointers, or questioning slice/map internals.

Comprehensive guide for dependency injection (DI) in Golang. Covers why DI matters (testability, loose coupling, separation of concerns, lifecycle management), manual constructor injection, and DI library comparison (google/wire, uber-go/dig, uber-go/fx, samber/do). Use this skill when designing service architecture, setting up dependency injection, refactoring tightly coupled code, managing singletons or service factories, or when the user asks about inversion of control, service containers, or wiring dependencies in Go. For a specific DI library, → See `samber/cc-skills-golang@golang-google-wire`, `samber/cc-skills-golang@golang-uber-dig`, `samber/cc-skills-golang@golang-uber-fx`, or `samber/cc-skills-golang@golang-samber-do` skills.

Implements GraphQL APIs in Golang using gqlgen or graphql-go. Apply when building GraphQL servers, designing schemas, writing resolvers, handling subscriptions, or integrating GraphQL with existing Go HTTP services. Also apply when the codebase imports `github.com/99designs/gqlgen` or `github.com/graph-gophers/graphql-go`.

Golang CLI application development. Use when building, modifying, or reviewing a Go CLI tool — especially for command structure, flag handling, configuration layering, version embedding, exit codes, I/O patterns, signal handling, shell completion, argument validation, and CLI unit testing. Also triggers when code uses cobra, viper, or urfave/cli. For cobra-specific APIs → See `samber/cc-skills-golang@golang-spf13-cobra` skill; for viper configuration layering → See `samber/cc-skills-golang@golang-spf13-viper` skill.