# Licenses tool > This is not an officially supported Google product. \`go-licenses\` analyzes the dependency tree of a Go package/binary. It can output a report on the libraries used and under what license they can be used. It can also collect all of the license documents, copyright notices and source code into a directory in order to comply with license terms on redistribution. ## Before you start To use this tool, make sure: * [You have Go v1.16 or later installed](https://golang.org/dl/). * Change directory to your go project, **for example**: \`\`\`shell git clone git@github.com:google/go-licenses.git cd go-licenses \`\`\` * Download required modules: \`\`\`shell go mod download \`\`\` ## Installation Use the following command to download and install this tool: \`\`\`shell go install github.com/google/go-licenses/v2@latest \`\`\` If you were using \`go get\` to install this tool, note that [starting in Go 1.17, go get is deprecated for installing binaries](https://go.dev/doc/go-get-install-deprecation). ## Reports \`\`\`shell $ go-licenses report github.com/google/go-licenses W0410 06:02:57.077781 31529 library.go:86] "golang.org/x/sys/unix" contains non-Go code that can't be inspected for further dependencies: /home/username/go/pkg/mod/golang.org/x/sys@v0.0.0-20220111092808-5a964db01320/unix/asm_linux_amd64.s W0410 06:02:59.476443 31529 library.go:86] "golang.org/x/crypto/curve25519/internal/field" contains non-Go code that can't be inspected for further dependencies: /home/username/go/pkg/mod/golang.org/x/crypto@v0.0.0-20220112180741-5e0467b6c7ce/curve25519/internal/field/fe_amd64.s W0410 06:02:59.486045 31529 library.go:86] "golang.org/x/crypto/internal/poly1305" contains non-Go code that can't be inspected for further dependencies: /home/username/go/pkg/mod/golang.org/x/crypto@v0.0.0-20220112180741-5e0467b6c7ce/internal/poly1305/sum_amd64.s W0410 06:02:59.872215 31529 library.go:253] module github.com/google/go-licenses has empty version, defaults to HEAD. The license URL may be incorrect. Please verify! W0410 06:02:59.880621 31529 library.go:253] module github.com/google/go-licenses has empty version, defaults to HEAD. The license URL may be incorrect. Please verify! github.com/emirpasic/gods,https://github.com/emirpasic/gods/blob/v1.12.0/LICENSE,BSD-2-Clause github.com/golang/glog,https://github.com/golang/glog/blob/23def4e6c14b/LICENSE,Apache-2.0 github.com/golang/groupcache/lru,https://github.com/golang/groupcache/blob/41bb18bfe9da/LICENSE,Apache-2.0 github.com/google/go-licenses,https://github.com/google/go-licenses/blob/HEAD/LICENSE,Apache-2.0 github.com/google/go-licenses/internal/third_party/pkgsite,https://github.com/google/go-licenses/blob/HEAD/internal/third_party/pkgsite/LICENSE,BSD-3-Clause github.com/google/licenseclassifier,https://github.com/google/licenseclassifier/blob/3043a050f148/LICENSE,Apache-2.0 github.com/google/licenseclassifier/stringclassifier,https://github.com/google/licenseclassifier/blob/3043a050f148/stringclassifier/LICENSE,Apache-2.0 github.com/jbenet/go-context/io,https://github.com/jbenet/go-context/blob/d14ea06fba99/LICENSE,MIT github.com/kevinburke/ssh_config,https://github.com/kevinburke/ssh_config/blob/01f96b0aa0cd/LICENSE,MIT github.com/mitchellh/go-homedir,https://github.com/mitchellh/go-homedir/blob/v1.1.0/LICENSE,MIT github.com/otiai10/copy,https://github.com/otiai10/copy/blob/v1.6.0/LICENSE,MIT github.com/sergi/go-diff/diffmatchpatch,https://github.com/sergi/go-diff/blob/v1.2.0/LICENSE,MIT github.com/spf13/cobra,https://github.com/spf13/cobra/blob/v1.4.0/LICENSE.txt,Apache-2.0 github.com/spf13/pflag,https://github.com/spf13/pflag/blob/v1.0.5/LICENSE,BSD-3-Clause github.com/src-d/gcfg,https://github.com/src-d/gcfg/blob/v1.4.0/LICENSE,BSD-3-Clause github.com/xanzy/ssh-agent,https://github.com/xanzy/ssh-agent/blob/v0.2.1/LICENSE,Apache-2.0 go.opencensus.io,https://github.com/census-instrumentation/opencensus-go/blob/v0.23.0/LICENSE,Apache-2.0 golang.org/x/crypto,https://cs.opensource.google/go/x/crypto/+/5e0467b6:LICENSE,BSD-3-Clause golang.org/x/mod/semver,https://cs.opensource.google/go/x/mod/+/9b9b3d81:LICENSE,BSD-3-Clause golang.org/x/net,https://cs.opensource.google/go/x/net/+/69e39bad:LICENSE,BSD-3-Clause golang.org/x/sys,https://cs.opensource.google/go/x/sys/+/5a964db0:LICENSE,BSD-3-Clause golang.org/x/tools,https://cs.opensource.google/go/x/tools/+/v0.1.10:LICENSE,BSD-3-Clause golang.org/x/xerrors,https://cs.opensource.google/go/x/xerrors/+/5ec99f83:LICENSE,BSD-3-Clause gopkg.in/src-d/go-billy.v4,https://github.com/src-d/go-billy/blob/v4.3.2/LICENSE,Apache-2.0 gopkg.in/src-d/go-git.v4,https://github.com/src-d/go-git/blob/v4.13.1/LICENSE,Apache-2.0 gopkg.in/warnings.v0,https://github.com/go-warnings/warnings/blob/v0.1.2/LICENSE,BSD-2-Clause \`\`\` This command prints out a comma-separated report (CSV) listing the libraries used by a binary/package, the URL where their licenses can be viewed and the type of license. A library is considered to be one or more Go packages that share a license file. URLs are versioned based on go modules metadata. **Tip**: go-licenses writes the report to stdout and info/warnings/errors logs to stderr. To save the CSV to a file \`licenses.csv\` in bash, run: \`\`\`bash go-licenses report github.com/google/go-licenses > licenses.csv \`\`\` Or, to also save error logs to an \`errors\` file, run: \`\`\`bash go-licenses report github.com/google/go-licenses > licenses.csv 2> errors \`\`\` **Note**: some warnings and errors may be expected, refer to [Warnings and Errors](#warnings-and-errors) for more information. ## Reports with Custom Templates \`\`\`shell go-licenses report github.com/google/go-licenses --template testdata/modules/hello01/licenses.tpl W0822 16:56:50.696198 10200 library.go:94] "golang.org/x/sys/unix" contains non-Go code that can't be inspected for further dependencies: /Users/willnorris/go/pkg/mod/golang.org/x/sys@v0.0.0-20220722155257-8c9f86f7a55f/unix/asm_bsd_arm64.s /Users/willnorris/go/pkg/mod/golang.org/x/sys@v0.0.0-20220722155257-8c9f86f7a55f/unix/zsyscall_darwin_arm64.1_13.s /Users/willnorris/go/pkg/mod/golang.org/x/sys@v0.0.0-20220722155257-8c9f86f7a55f/unix/zsyscall_darwin_arm64.s W0822 16:56:51.466449 10200 library.go:94] "golang.org/x/crypto/chacha20" contains non-Go code that can't be inspected for further dependencies: /Users/willnorris/go/pkg/mod/golang.org/x/crypto@v0.0.0-20220112180741-5e0467b6c7ce/chacha20/chacha_arm64.s W0822 16:56:51.475139 10200 library.go:94] "golang.org/x/crypto/curve25519/internal/field" contains non-Go code that can't be inspected for further dependencies: /Users/willnorris/go/pkg/mod/golang.org/x/crypto@v0.0.0-20220112180741-5e0467b6c7ce/curve25519/internal/field/fe_arm64.s W0822 16:56:51.602250 10200 library.go:269] module github.com/google/go-licenses has empty version, defaults to HEAD. The license URL may be incorrect. Please verify! W0822 16:56:51.605074 10200 library.go:269] module github.com/google/go-licenses has empty version, defaults to HEAD. The license URL may be incorrect. Please verify! - github.com/emirpasic/gods ([BSD-2-Clause](https://github.com/emirpasic/gods/blob/v1.12.0/LICENSE)) - github.com/golang/glog ([Apache-2.0](https://github.com/golang/glog/blob/23def4e6c14b/LICENSE)) - github.com/golang/groupcache/lru ([Apache-2.0](https://github.com/golang/groupcache/blob/41bb18bfe9da/LICENSE)) - github.com/google/go-licenses ([Apache-2.0](https://github.com/google/go-licenses/blob/HEAD/LICENSE)) - github.com/google/go-licenses/internal/third_party/pkgsite ([BSD-3-Clause](https://github.com/google/go-licenses/blob/HEAD/internal/third_party/pkgsite/LICENSE)) - github.com/google/licenseclassifier ([Apache-2.0](https://github.com/google/licenseclassifier/blob/3043a050f148/LICENSE)) - github.com/google/licenseclassifier/licenses ([Unlicense](https://github.com/google/licenseclassifier/blob/3043a050f148/licenses/Unlicense.txt)) - github.com/google/licenseclassifier/stringclassifier ([Apache-2.0](https://github.com/google/licenseclassifier/blob/3043a050f148/stringclassifier/LICENSE)) - github.com/jbenet/go-context/io ([MIT](https://github.com/jbenet/go-context/blob/d14ea06fba99/LICENSE)) - github.com/kevinburke/ssh_config ([MIT](https://github.com/kevinburke/ssh_config/blob/01f96b0aa0cd/LICENSE)) - github.com/mitchellh/go-homedir ([MIT](https://github.com/mitchellh/go-homedir/blob/v1.1.0/LICENSE)) - github.com/otiai10/copy ([MIT](https://github.com/otiai10/copy/blob/v1.6.0/LICENSE)) - github.com/sergi/go-diff/diffmatchpatch ([MIT](https://github.com/sergi/go-diff/blob/v1.2.0/LICENSE)) - github.com/spf13/cobra ([Apache-2.0](https://github.com/spf13/cobra/blob/v1.5.0/LICENSE.txt)) - github.com/spf13/pflag ([BSD-3-Clause](https://github.com/spf13/pflag/blob/v1.0.5/LICENSE)) - github.com/src-d/gcfg ([BSD-3-Clause](https://github.com/src-d/gcfg/blob/v1.4.0/LICENSE)) - github.com/xanzy/ssh-agent ([Apache-2.0](https://github.com/xanzy/ssh-agent/blob/v0.2.1/LICENSE)) - go.opencensus.io ([Apache-2.0](https://github.com/census-instrumentation/opencensus-go/blob/v0.23.0/LICENSE)) - golang.org/x/crypto ([BSD-3-Clause](https://cs.opensource.google/go/x/crypto/+/5e0467b6:LICENSE)) - golang.org/x/mod/semver ([BSD-3-Clause](https://cs.opensource.google/go/x/mod/+/86c51ed2:LICENSE)) - golang.org/x/net ([BSD-3-Clause](https://cs.opensource.google/go/x/net/+/a158d28d:LICENSE)) - golang.org/x/sys ([BSD-3-Clause](https://cs.opensource.google/go/x/sys/+/8c9f86f7:LICENSE)) - golang.org/x/tools ([BSD-3-Clause](https://cs.opensource.google/go/x/tools/+/v0.1.12:LICENSE)) - gopkg.in/src-d/go-billy.v4 ([Apache-2.0](https://github.com/src-d/go-billy/blob/v4.3.2/LICENSE)) - gopkg.in/src-d/go-git.v4 ([Apache-2.0](https://github.com/src-d/go-git/blob/v4.13.1/LICENSE)) - gopkg.in/warnings.v0 ([BSD-2-Clause](https://github.com/go-warnings/warnings/blob/v0.1.2/LICENSE)) \`\`\` This command executes a specified Go template file to generate a report of licenses. The template file is passed a slice of structs containing license data: \`\`\`go []struct \{ Name string Version string LicenseURL string LicenseName string LicensePath string \} \`\`\` Each struct also has a \`LicenseText\` method which will return the text of the license stored at \`LicensePath\` if present, or an empty string if not. Example template rendering licenses as markdown: \`\`\`\` \{\{ range . \}\} ## \{\{ .Name \}\} * Name: \{\{ .Name \}\} * Version: \{\{ .Version \}\} * License: [\{\{ .LicenseName \}\}](\{\{ .LicenseURL \}\}) \`\`\` \{\{ .LicenseText \}\} \`\`\` \{\{ end \}\} \`\`\`\` ## Save licenses, copyright notices and source code (depending on license type) \`\`\`shell go-licenses save "github.com/google/go-licenses" --save_path="/tmp/go-licenses-cli" \`\`\` This command analyzes a binary/package's dependencies and determines what needs to be redistributed alongside that binary/package in order to comply with the license terms. This typically includes the license itself and a copyright notice, but may also include the dependency's source code. All of the required artifacts will be saved in the directory indicated by \`--save_path\`. ## Checking for forbidden licenses \`\`\`shell $ go-licenses check github.com/logrusorgru/aurora Forbidden license type WTFPL for library github.com/logrusorgru/auroraexit status 1 \`\`\` This command analyzes a package's dependencies and determines if any are considered forbidden by the license classifer. See [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/842c0d70d7027215932deb13801890992c9ba364/license_type.go#L323) for licenses considered forbidden. ## Usages ### Global Typically, specify the Go package that builds your Go binary. go-licenses expects the same package argument format as \`go build\`. For examples: * A rooted import path like \`github.com/google/go-licenses\` or \`github.com/google/go-licenses/licenses\`. * A relative path that denotes the package in that directory, like \`.\` or \`./cmd/some-command\`. To learn more about package argument, run \`go help packages\`. To learn more about go-licenses usages, run \`go-licenses help\`. ### Report Report usage (default csv output): \`\`\`shell go-licenses report [package...] \`\`\` Report usage (using custom template file): \`\`\`shell go-licenses report [package...] --template= \`\`\` ### Save Save licenses, copyright notices and source code (depending on license type): \`\`\`shell go-licenses save [package...] --save_path= \`\`\` ### Check Checking for forbidden and unknown licenses usage: \`\`\`shell go-licenses check [package...] \`\`\` **Tip**: Usually you'll want to * append \`/...\` to the end of an import path prefix (e.g., your repo path) to include all packages matching that pattern * add \`--include_tests\` to also check packages only imported by testing code (e.g., testing libraries/frameworks) \`\`\`shell go-licenses check --include_tests github.com/google/go-licenses/... \`\`\` Checking for disallowed license types: \`\`\`shell go-licenses check [package...] --disallowed_types= \`\`\` Supported license types: * See \`forbidden\` list: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L341) * See \`notice\` list: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L249) * See \`permissive\` list: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L321) * See \`reciprocal\` list: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L225) * See \`restricted\` list: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L185) * See \`unencumbered\` list: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L324) * \`unknown\` Allow only specific license names: \`\`\`shell go-licenses check [package...] --allowed_licenses= \`\`\` * See supported license names: [github.com/google/licenseclassifier](https://github.com/google/licenseclassifier/blob/e6a9bb99b5a6f71d5a34336b8245e305f5430f99/license_type.go#L28) ### Build tags To read dependencies from packages with [build tags](https://golang.org/pkg/go/build/#hdr-Build_Constraints). Use the \`$GOFLAGS\` environment variable. \`\`\`shell $ GOFLAGS="-tags=tools" go-licenses report google.golang.org/grpc/test/tools github.com/BurntSushi/toml,https://github.com/BurntSushi/toml/blob/master/COPYING,MIT google.golang.org/grpc/test/tools,Unknown,Apache-2.0 honnef.co/go/tools/lint,Unknown,BSD-3-Clause golang.org/x/lint,Unknown,BSD-3-Clause golang.org/x/tools,Unknown,BSD-3-Clause honnef.co/go/tools,Unknown,MIT honnef.co/go/tools/ssa,Unknown,BSD-3-Clause github.com/client9/misspell,https://github.com/client9/misspell/blob/master/LICENSE,MIT github.com/golang/protobuf/proto,https://github.com/golang/protobuf/blob/master/proto/LICENSE,BSD-3-Clause \`\`\` ### Ignoring packages Use the \`--ignore\` global flag to specify package path prefixes to be ignored. For example, to ignore your organization's internal packages under \`github.com/example-corporation\`: \`\`\`shell $ go-licenses check \ github.com/example-corporation/example-product \ --ignore github.com/example-corporation \`\`\` Note that dependencies from the ignored packages are still resolved and checked. This flag makes effect to \`check\`, \`report\` and \`save\` commands. ### Include testing packages Use the \`--include_tests\` global flag to include packages only imported by testing code (e.g., testing libraries/frameworks). Example command: \`\`\`shell go-licenses check --include_tests "github.com/google/go-licenses/..." \`\`\` This flag makes effect to \`check\`, \`report\` and \`save\` commands. ## Warnings and errors The tool will log warnings and errors in some scenarios. This section provides guidance on addressing them. ### Dependency contains non-Go code A warning will be logged when a dependency contains non-Go code. This is because it is not possible to check the non-Go code for further dependencies, which may conceal additional license requirements. You should investigate this code to determine whether it has dependencies and take action to comply with their license terms. ### Error discovering URL In order to determine the URL where a license file can be viewed, this tool generally performs the following steps: 1. Locates the license file on disk. 2. Parses go module metadata and finds the remote repo and version. 3. Adds the license file path to this URL. There are cases this tool finds an invalid/incorrect URL or fails to find the URL. Welcome [creating an issue](https://github.com/google/go-licenses/issues).