Golang Pkg Go Dev

golang-pkg-go-dev

Dependencies: godig — go install github.com/samber/godig/cmd/godig@latest (or use a registered godig MCP server / the hosted instance instead).

godig queries the pkg.go.dev API. Use it to answer questions about Go packages and modules: docs, symbols, versions, importers and vulnerabilities. It works as a CLI and as an MCP server, and all operations are read-only and need no authentication.

When to use this skill

Trigger on questions like:

• "What versions of github.com/samber/lo are available?"
• "Does golang.org/x/text have known vulnerabilities?"
• "Show me the docs / symbols for package X."
• "Which packages import X?"
• "Search Go packages for Y."

Choosing between godig, gopls, Context7, and govulncheck

In short: godig answers questions about the published ecosystem (works even for packages not yet in your go.mod); gopls reasons about your locally resolved build (go.sum, including replaced forks); Context7 is a fallback for non-Go or unindexed docs; govulncheck is the whole-tree vulnerability audit (→ samber/cc-skills-golang@golang-security). See the samber/cc-skills-golang@golang-gopls skill for wiring gopls (MCP server, native LSP tool, and CLI) with Claude Code, and the samber/cc-skills-golang@golang-how-to skill's "godig vs gopls vs Context7 vs govulncheck" section for the full task-to-tool matrix.

Setup

Install

go install github.com/samber/godig/cmd/godig@latest

Register the MCP server (optional)

godig mcp runs over stdio by default, or streamable HTTP with --transport http. The command is harness-agnostic — any MCP-capable host can point at it. Claude Code registers it via its own CLI:

stdio (the client launches godig on demand):

claude mcp add pkg-go-dev -- godig mcp

streamable HTTP (shared server at /mcp, default :8080):

godig mcp --transport http --addr :8080
claude mcp add --transport http pkg-go-dev http://localhost:8080/mcp

Hosted instance (no install needed) — a public server runs at https://godig.samber.dev/mcp:

claude mcp add --transport http pkg-go-dev https://godig.samber.dev/mcp

Other MCP-capable harnesses (Cursor, Windsurf, and others) each have their own MCP server registration — an entry in their respective settings file pointing at the same godig mcp command or hosted URL, not a shared config format.

The CLI and the MCP server expose the same operations under matching names. Prefer the CLI when godig is installed; the hosted instance is a fallback when it is not.

Commands

Global flags (all commands): -o/--output table|json|raw|md (default table — pass -o md for chat), --base-url (pkg.go.dev API), --vuln-base-url (Go vulnerability database, consulted by vulns and overview), --timeout, --log-level debug|info|warn|error|off. All are also settable via GODIG_* env vars.

When godig runs as an MCP server, each data command above is exposed as an operation of the same name.

Exit codes: 0 success, 1 runtime error (network, package not found), 2 usage error — a missing/invalid argument or flag (e.g. a non-positive --limit), or a command group invoked with no subcommand (godig package). Check for 2 to tell a malformed call apart from a failed lookup.

Full -o md output for every command: sample-output.md.

Tips

• Start with `overview` — one call returns a compact summary (metadata, latest + recent versions, license types, vulnerabilities). Reach for doc/examples/module readme/licenses (LARGE) only when the full text is needed.
• Always pass `-o md` so results render as Markdown (tables, or raw doc/README) in the chat. Other formats exist (table default, json, raw) but prefer md here.
• <path> is a full import path, e.g. github.com/samber/lo — pass it as the positional argument.
• --version pins a specific module version (v1.5.0, latest, master, main); --module disambiguates which module a package belongs to.
• --filter narrows list results server-side with a Go boolean expression — see Filter syntax.
• --goos/--goarch set the documentation/symbols build context (e.g. linux/amd64).
• Prefer symbol doc/symbol examples over the package-wide package doc/package examples when you only need one symbol — far fewer tokens.
• Parallelize independent lookups — every command is a self-contained, read-only HTTP query, so calls never depend on each other. When a task needs docs, examples, versions, or vulns for several symbols, packages, or modules, issue all the calls at once (multiple godig invocations in a single turn) rather than one after another — wall-clock drops from sum-of-latencies to slowest-single-call. For a large fan-out (documenting many symbols, comparing many candidate libraries, auditing CVEs across a dependency set), dispatch up to 5 parallel sub-agents, each running its own godig calls and returning a compact summary, so the raw LARGE output never lands in the main context.
• Listing commands auto-paginate (return all results); use --limit to cap.

Filter syntax

--filter (on search, versions, major-versions, packages, imported-by, symbols) takes a Go boolean expression evaluated server-side, once per result item. It is not a regex — wrap the whole expression in single quotes for the shell.