Modules Commands

Manage Go dependencies with modules. Initialize projects, add dependencies, upgrade versions, and understand go.sum for reproducible builds across teams.

12 commands

Pro Tips

Use 'go mod tidy' regularly to remove unused dependencies and add missing ones — keeps go.mod clean.

Use 'go get -u ./...' to update all dependencies, or 'go get -u pkg@latest' for a specific package.

Use 'go mod vendor' to create a vendor directory for offline builds and faster CI.

Common Mistakes

Always commit both go.mod AND go.sum. The sum file ensures dependency integrity and reproducible builds.

Running 'go get -u' updates ALL dependencies including transitive ones. This can introduce breaking changes.

Commands

Initialize module

$ go mod init github.com/user/project

Create new Go module (generates go.mod).

Tidy dependencies

$ go mod tidy

Add missing and remove unused dependencies.

Download dependencies

$ go mod download

Download modules to local cache.

Vendor dependencies

$ go mod vendor

Copy dependencies to vendor directory.

Verify dependencies

$ go mod verify

Verify dependencies match go.sum checksums.

Show dependency graph

$ go mod graph

Print module dependency graph.

Explain why needed

$ go mod why golang.org/x/sync

Explain why a package/module is needed.

Add dependency

$ go get github.com/gin-gonic/gin@latest

Add package to module dependencies.

Add specific version

$ go get github.com/pkg/errors@v0.9.1

Add package at specific version.

Update all dependencies

$ go get -u ./...

Update all dependencies to latest minor/patch.

Edit go.mod (replace)

$ go mod edit -replace=github.com/old/pkg=../local/pkg

Add module replacement for local development.

List all modules

$ go list -m all

List all module dependencies.