# Install falco with Homebrew VCL parser and linter optimized for Fastly. Version 2.3.0 via Homebrew; verified 2026-05-01. ## Install ```sh sudo av install brew:falco ``` Additional install commands: ### macOS - Homebrew (100%): ```sh brew install falco ``` Evidence: local Homebrew formula metadata ## Package facts - **Package key:** brew:falco - **Package manager:** Homebrew - **Package manager page:** - **Version:** 2.3.0 - **Source summary:** VCL parser and linter optimized for Fastly - **Homepage:** - **Repository:** - **Upstream docs:** - **License:** MIT - **Source archive:** - **Last updated:** 2026-05-01T17:43:28Z - **Generated:** 2026-07-08T18:08:21+00:00 ## Executables - falco (cli) - falco (alias) ## Build dependencies - go ## Install behavior - Post-install hook: not defined - Bottle: available on arm64_linux, arm64_sequoia, arm64_sonoma, arm64_tahoe, sonoma, x86_64_linux ## Freshness - Page generated: 2026-07-08 - Package-manager version: 2.3.0 - Package-manager updated: 2026-05-01 - Local data: ok - Upstream repository: https://github.com/ysugimoto/falco - Upstream latest detected: v2.3.0 (current) ## Project history and usage falco is a Fastly VCL developer tool, parser, linter, formatter, local simulator, debugger, and test runner. It is unrelated to the Falco cloud-native security project; the Homebrew formula points to ysugimoto/falco, whose README describes it as a Fastly VCL tool. ### Project history The project was created in July 2021 to make Fastly custom VCL development less dependent on slow remote deployment validation. Its README frames the core problem as a deployment loop where service versions are cloned, custom VCL is uploaded, and syntax errors are discovered only when Fastly validates activation. The implementation grew from local parsing and linting into a broader developer workflow: formatting, statistics, a VCL interpreter-backed local simulator, a debugger, unit testing written in VCL, a console, and Terraform plan support for the Fastly provider. ### Adoption history Official install paths include downloadable GitHub release binaries, Homebrew, and `go install`, which places the tool in the normal package-manager and Go-toolchain channels used by Fastly VCL maintainers. The README also documents GitHub Actions usage through a separate falco-github-action, showing CI linting as a first-class workflow. ### How it is used The default workflow is `falco lint`, often run with include paths and verbose output against a main VCL file before deployment. Other subcommands cover `fmt`, `simulate`, `test`, `console`, `stats`, and `terraform`, making the CLI useful both interactively and in automated checks. The tool is intentionally Fastly-specific. The README says it targets Fastly VCL 2.x and does not try to track newer generic Varnish syntax, because Fastly adds its own builtins, predefined variables, and compatibility constraints. ### Why package nerds care For package-manager users, this falco is a good example of a niche operational CLI whose package name collides with a much larger security project. Its significance is in bringing CDN configuration validation, formatting, simulation, and tests into local shells and CI rather than leaving mistakes to remote Fastly activation. ### Timeline - 2021: Repository created for a Fastly-focused VCL developer tool. - 2021: v0.1.0 released on GitHub. - 2025: v2.0.0 released. - 2026: v2.3.0 released. ### Related projects - Fastly custom VCL is the primary target environment. - The README documents Terraform plan support for the Fastly Terraform provider. - The README links a GitHub Action for CI linting. ### Sources - - - - ## Security Notes narrow executable package without higher-risk signals. - **Geiger risk:** green / low - narrow executable package without higher-risk signals ## Source Database Details - **Source Database:** Homebrew formula API - **Tap:** homebrew/core - **Full Name:** falco - **Version Scheme:** 0 - **Revision:** 0 - **Head Version:** HEAD - **Bottle Stable Root URL:** - **Deprecated:** no - **Disabled:** no - **Keg Only:** no - **URL Keys:** head, stable ## Related links - [Source-control packages](https://www.automicvault.com/pkg/source-control-tools/) - Belongs to a source-control command family. - [Terminal utility packages](https://www.automicvault.com/pkg/terminal-utilities/) - Matched terminal and command-line workflow metadata. - [Text processing packages](https://www.automicvault.com/pkg/text-processing-tools/) - Matched text, document, or structured-data processing metadata. - [Developer build packages](https://www.automicvault.com/pkg/developer-build-tools/) - Matched build, compiler, generator, or developer workflow metadata. - [go](https://www.automicvault.com/pkg/brew/go/) - Build dependency declared by Homebrew. - [doc8](https://www.automicvault.com/pkg/brew/doc8/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [elvis](https://www.automicvault.com/pkg/brew/elvis/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [gitlint](https://www.automicvault.com/pkg/brew/gitlint/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [htmlhint](https://www.automicvault.com/pkg/brew/htmlhint/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [iblinter](https://www.automicvault.com/pkg/brew/iblinter/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [mado](https://www.automicvault.com/pkg/brew/mado/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [oxlint](https://www.automicvault.com/pkg/brew/oxlint/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. - [proselint](https://www.automicvault.com/pkg/brew/proselint/) - Shares av.db curated category or tags: cli, developer-tools, linter, linting. ## Combined YAML source View the package source record on GitHub. [combined/falco.yml](https://github.com/automic-vault/db/blob/main/combined/falco.yml) ## Sources - Nucleus package database - Geiger risk classifier - package-page enrichment - curated package history - package version freshness - av.db category and tag curation - package relationship graph - cross-ecosystem install command graph