Install ytt with Homebrew, apk, MacPorts, Nix, scoop, winget

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• ytt

Project history

ytt was introduced publicly in March 2019 as the YAML Templating Tool, with IBM Developer describing v0.1.0 as a new approach to complex configuration management. The GitHub repository was created the same month, and early releases followed rapidly through spring and summer 2019.

The tool emerged from the k14s/Carvel ecosystem around Kubernetes configuration. Its core design responded to a common pain in Helm, Jinja, ERB, and other text-templating approaches: YAML indentation, quoting, and patching errors caused by treating structured configuration as strings. ytt instead embeds Starlark through `#@` annotations and evaluates templates into YAML structures.

As k14s became Carvel, ytt settled into a suite of small composable Kubernetes tools alongside kapp, kbld, imgpkg, vendir, kapp-controller, and kctrl. The Carvel site frames the suite as single-purpose, composable tools for building, configuring, and deploying applications on Kubernetes.

Adoption history

ytt adoption has been strongest in Kubernetes and Tanzu/Carvel workflows. Broadcom VMware Tanzu documentation bundles ytt with other Carvel tools in Tanzu Kubernetes Grid contexts, and Carvel maintains community channels, an adopter list, examples, an online playground, and reusable libraries such as ytt Library for Kubernetes.

Outside Tanzu, ytt is adopted by users who want more programmability than Kustomize overlays but less text-fragility than Helm-style templating. Blog posts and talks often present it as an alternative or complement to Helm, Kustomize, Jsonnet, and Dhall in Kubernetes configuration pipelines.

How it is used

Users run ytt to template, patch, validate, and compose YAML files. Common patterns include data values for environment-specific configuration, overlays for patching third-party YAML, Starlark functions for reusable logic, schema and validations for fast feedback, and integration into GitOps or packaging flows.

The package is especially useful when a team has piles of Kubernetes YAML and wants programmable reuse while preserving YAML structure. Its online playground and local `ytt website` mode also make examples easy to test without wiring a cluster.

Why package nerds care

ytt matters to package nerds because it shows a distinct packaging philosophy: do one YAML-shaping job well, compose with neighboring tools, and avoid making the templater also be the package manager, deployer, and image builder.

It is also one of the clearer examples of Starlark moving beyond Bazel into infrastructure configuration. In dependency graphs, seeing ytt often hints at Carvel-style Kubernetes delivery rather than Helm-only packaging.

Timeline

• 2019-03-01: The carvel-dev/ytt GitHub repository is created.
• 2019-03-12: IBM Developer announces ytt v0.1.0 as a new YAML templating approach.
• 2019-03-20: ytt v0.4.0 appears in GitHub releases, followed by frequent early releases.
• 2020-2021: k14s tooling is increasingly described under the Carvel name and used in Tanzu Kubernetes workflows.
• 2020s: ytt remains one of the core Carvel tools alongside kapp, kbld, imgpkg, vendir, and kapp-controller.

Related projects

• Related projects include Carvel, k14s, kapp, kbld, imgpkg, vendir, kapp-controller, kctrl, Helm, Kustomize, Jsonnet, Dhall, Starlark, Kubernetes, and Tanzu Kubernetes Grid.

Sources

• https://api.github.com/repos/carvel-dev/ytt
• https://carvel.dev/
• https://carvel.dev/blog/parameterizing-project-config-with-ytt/
• https://carvel.dev/ytt/
• https://developer.ibm.com/blogs/yaml-templating-tool-to-simplify-complex-configuration-management/
• https://github.com/carvel-dev/ytt
• https://github.com/carvel-dev/ytt-library-for-kubernetes
• https://techdocs.broadcom.com/us/en/vmware-tanzu/standalone-components/tanzu-kubernetes-grid/2-4/using-tkg/workload-carvel-tools.html