Install oj with Homebrew

Project links

• Homepage

Commands and aliases

• oj

Project history

OjG was created by Peter Ohler, author of the older Ruby `oj` gem and C `ojc` parser. The repository was created on 2020-04-12. Its design document says the project began from the idea of building a fast JSON parser, generic data model, and full JSONPath implementation for Go, informed by Ohler's earlier JSON parser work.

The project architecture split functionality into packages such as `oj` for parsing, `jp` for JSONPath, `gen` for generic JSON node types, `alt`, `asm`, `sen`, and later `discover`. The `oj` command wraps those libraries for shell use: filtering and extracting with JSONPath, sorting, reformatting, discovering JSON in documents, and colorizing output.

The changelog shows steady evolution after the early releases. Version 1.10.0 in 2021 added a tokenizing callback parser; later releases added path matching, match handlers, script function registration, JSON discovery, and compatibility fixes while keeping semantic versioning.

Adoption history

OjG is niche but visible in Go JSON-performance circles. The GitHub API reported 950 stars and 53 forks, while Homebrew's 2026-07-01 formula API reported 194 installs over 365 days for the CLI package. Its appeal is strongest where developers want JSONPath over arbitrary JSON-like data or a command-line JSON filter with Go-native implementation details.

The README positions OjG against Go's standard `encoding/json` package through parser, reader, validator, and writer benchmarks, with benchmark links and a separate comparison repository. That performance framing is the main adoption hook.

How it is used

Go developers import packages such as `github.com/ohler55/ojg/oj` for parsing and validation, `jp` for JSONPath expressions, and `gen` for type-safe generic data. CLI users install `github.com/ohler55/ojg/cmd/oj` or `brew install oj` to query and format JSON from files and streams.

The parser can process a single JSON document or multiple JSON elements, and options allow comments in JSON. The command-line tool uses JSONPath expressions for filtering, extraction, sorting, reformatting, discovery, and colorized output.

Why package nerds care

The package is a good example of a name collision resolved by package-manager context: Homebrew's `oj` is not the older Ruby gem, but the Go command from OjG. Its upstream project still deliberately links the Go implementation to Ohler's Ruby `Oj` and C `OjC` lineage.

For maintainers, `oj` is a compact Go CLI package with no runtime dependencies in Homebrew, but it carries a rich upstream library surface. The formula's distinction between the CLI name `oj` and upstream module `ojg` is the kind of metadata wrinkle package nerds notice.

Timeline

• 2020-04-12: the `ohler55/ojg` repository was created.
• 2021-04-22: version 1.10.0 added the tokenizing callback parser.
• 2023-10-03: version 1.19.4 updated the command version and referenced the Homebrew formula.
• 2025-11-11: version 1.27.0 added the `discover` package and discovery option to the `oj` application.
• 2026-03-16: version 1.28.1 removed an accidental Go 1.22 dependency in `alt.Checksum()`.
• 2026-07-01: Homebrew's formula API reported stable version 1.28.1 for `oj`.

Related projects

• OjG is related to Ohler's Ruby `Oj`, C `OjC`, Ruby XML parser `Ox`, and web-server projects such as Agoo. It is also related to the IETF JSONPath work and to Go JSON parser comparison projects.

Sources

• https://api.github.com/repos/ohler55/ojg
• https://formulae.brew.sh/api/formula/oj.json
• https://github.com/ohler55/ojg
• https://pkg.go.dev/github.com/ohler55/ojg
• https://pkg.go.dev/github.com/ohler55/ojg/oj
• https://raw.githubusercontent.com/ohler55/ojg/develop/CHANGELOG.md
• https://raw.githubusercontent.com/ohler55/ojg/develop/README.md
• https://raw.githubusercontent.com/ohler55/ojg/develop/design.md