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. 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."

Setup

Install

bash

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

stdio (the client launches godig on demand):

bash

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

streamable HTTP (shared server at

/mcp

, default

:8080

bash

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

bash

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

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

--timeout

--log-level debug|info|warn|error|off

. All are also settable via

GODIG_*

env vars.

Command	Args	Specific flags	Purpose
`overview`	`<path>`	`--version`	Compact summary (metadata, versions, licenses, vulns) — start here
`search`	`<query>`	`--symbol --limit --filter`	Find packages (optionally exporting a symbol)
`package info`	`<path>`	`--module --version`	Package metadata
`package imports`	`<path>`	`--module --version`	Packages this package imports (plain list)
`package doc`	`<path>`	`--module --version --goos --goarch --format md\|text\|html\|markdown`	Full package doc (LARGE)
`package examples`	`<path>`	`--module --version --goos --goarch --symbol`	Runnable examples (LARGE; scope with `--symbol` )
`package licenses`	`<path>`	`--module --version`	License files, full text (LARGE)
`symbol doc`	`<path> <symbol>`	`--module --version --goos --goarch`	One symbol's signature + doc (token-efficient)
`symbol examples`	`<path> <symbol>`	`--module --version --goos --goarch`	One symbol's runnable examples
`symbols`	`<path>`	`--module --version --goos --goarch --limit --filter`	List exported symbols
`module info`	`<path>`	`--version`	Module metadata
`module licenses`	`<path>`	`--version`	Module license files (LARGE)
`module readme`	`<path>`	`--version`	Module README, full Markdown (LARGE)
`dependencies`	`<path>`	`--version`	go.mod deps: requires / replaces / excludes / go directive
`packages`	`<path>`	`--version --limit --filter`	Packages contained in a module
`versions`	`<path>`	`--limit --filter`	All versions, newest first
`major-versions`	`<path>`	`--limit --filter --exclude-pseudo`	Major versions (v1, v2 …) living as separate modules
`imported-by`	`<path>`	`--module --version --limit --filter`	Packages that import this one
`vulns`	`<path>`	`--module --version --limit --filter`	Known vulnerabilities
`mcp`	—	`--transport stdio\|http --addr --cache-ttl --cache-size`	Run as an MCP server
`version`	—	—	Print godig version / commit / build date

When

godig

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

Exit codes:

success,

runtime error (network, package not found),

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

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 parallel sub-agents (up to 5) via the Agent tool, 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

vulns

) 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.

Identifiers are the item's fields, which differ per command — a field valid for one list is rejected by another (e.g.
```
search
```
exposes
```
packagePath
```
, not
```
path
```
). An unknown field fails with
```
undefined identifier: <name>
```
(HTTP 400), which names the offending field. Casing is not uniform: most fields use the lowercase JSON key, but
```
vulns
```
uses Go-style names (
```
ID
```
, not
```
id
```
), and
```
kind
```
values are capitalized (
```
Function
```
, not
```
func
```
).
Operators:
```
==
```
```
!=
```
```
<
```
```
<=
```
```
>
```
```
>=
```
, boolean
```
&&
```
```
||
```
```
!
```
, parentheses for grouping.

String functions:

contains(s, sub)

hasPrefix(s, pre)

hasSuffix(s, suf)

Literals: double-quoted strings (
```
"Function"
```
),
```
true
```
/
```
false
```
, numbers.

Filterable fields per command (string unless noted):

Command	Fields
`search`	`modulePath` , `packagePath` , `synopsis` , `version`
`versions`	`version` , `modulePath` , `deprecated` (bool), `retracted` (bool), `hasGoMod` (bool), `commitTime`
`packages`	`path` , `name` , `synopsis` , `isRedistributable` (bool)
`imported-by`	`path` (the importing package path)
`symbols`	`name` , `kind` ( `Function` / `Method` / `Type` / `Variable` / `Constant` ), `synopsis` , `parent`
`vulns`	`ID` , `package` , `Details`
`major-versions`	`modulePath` , `major` , `version` , `isLatest` (bool)

bash

godig symbols github.com/samber/lo --filter 'kind=="Function"' -o md
godig symbols github.com/samber/lo --filter 'kind=="Function" && hasPrefix(name,"Map")' -o md
godig versions github.com/samber/lo --filter 'hasPrefix(version,"v1.5")' -o md
godig versions github.com/samber/lo --filter 'deprecated==false && retracted==false' -o md
godig search "result option" --filter 'hasPrefix(packagePath,"github.com/samber/")' -o md

Examples

Always request Markdown output (

-o md

bash

# Overview — start here (compact, one call)
godig overview github.com/samber/ro -o md

# Search
godig search "result option monad" --limit 5 -o md

# Package facets
godig package info github.com/samber/ro -o md
godig package imports github.com/samber/ro -o md
godig package doc github.com/samber/ro --format md -o md
godig package examples github.com/samber/ro --symbol Map -o md
godig package licenses github.com/samber/ro -o md

# Single symbol (token-efficient vs package-wide doc/examples)
godig symbol doc github.com/samber/lo Map -o md
godig symbol examples github.com/samber/oops OopsError.Error -o md

# Module facets
godig module info github.com/samber/ro -o md
godig module readme github.com/samber/ro -o raw
godig dependencies github.com/samber/ro -o md

# Lists (auto-paginated; --limit to cap)
godig versions github.com/samber/ro -o md
godig major-versions github.com/samber/lo -o md
godig packages github.com/samber/ro -o md
godig imported-by github.com/samber/ro --limit 20 -o md
godig symbols github.com/samber/ro --filter 'kind=="Function"' -o md

# Pin a version / set the build context
godig versions github.com/samber/ro --filter 'hasPrefix(version,"v0.3")' -o md
godig package doc github.com/samber/lo --version v1.50.0 -o md
godig symbols github.com/samber/ro --goos linux --goarch amd64 -o md

# Vulnerabilities
godig vulns github.com/samber/ro -o md

This skill is not exhaustive.

godig --help

and each sub-command's

--help

list current flags and output formats; the data mirrors what pkg.go.dev exposes.

If you encounter a bug or unexpected behavior in

godig

, open an issue at https://github.com/samber/godig/issues.

golang-pkg-go-dev

NPX Install

Tags

SKILL.md Content

golang-pkg-go-dev

When to use this skill

Setup

Install

Register the MCP server (optional)

Commands

Tips

Filter syntax

Examples