phel-lang/phel-lang

Phel is a functional programming language that compiles to PHP

v0.42.0 2026-06-06 09:43 UTC

Requires

• php: >=8.4
• amphp/amp: ^3.1
• gacela-project/gacela: ^1.14
• symfony/console: ^6.0|^7.0|^8.0
• symfony/routing: ^7.3|^8.0

Requires (Dev)

• ext-readline: *
• ergebnis/composer-normalize: ^2.50
• friendsofphp/php-cs-fixer: ^3.94
• phpbench/phpbench: ^1.6
• phpstan/phpstan: ^2.1
• phpunit/phpunit: ^11.0|^12.0|^13.0
• psalm/plugin-phpunit: ^0.19|^0.20
• rector/rector: ^2.3
• symfony/var-dumper: ^7.4|^8.0
• vimeo/psalm: ^6.16

MIT

• Jens Haase
• Jose M. Valera Reales

• language
• functional
• lisp
• phel

README

Lisp for PHP, macros, persistent data structures, REPL.

Get Started

composer require phel-lang/phel-lang

1. Open a REPL

./vendor/bin/phel repl

phel:1:> (->> [1 2 3 4 5] (filter odd?) (map #(* % %)) (reduce +))
35
phel:2:> (defn greet [name] (str "Hello, " name "!"))
| user/greet
phel:3:> (greet "Phel")
| "Hello, Phel!"

2. Scaffold a project

./vendor/bin/phel init         # add `--minimal` for a single-file layout

Creates phel-config.php, src/phel/main.phel, tests/phel/main_test.phel. Then:

./vendor/bin/phel run src/phel/main.phel   # run
./vendor/bin/phel test                     # tests
./vendor/bin/phel build                    # compile to PHP

3. Eval inline or via stdin

./vendor/bin/phel eval '(+ 1 2)'           # prints 3
echo '(println "hi")' | ./vendor/bin/phel eval -
./vendor/bin/phel eval - < script.phel

Prefer a project template? web-skeleton or cli-skeleton: click Use this template for a one-click start.

More examples →

Data pipeline (def users [{:name "Ada" :age 36} {:name "Bob" :age 17} {:name "Cam" :age 41}]) (->> users (filter #(>= (:age %) 18)) (map :name) sort) ;; => ["Ada" "Cam"]	HTTP response (ns app (:require phel.http :as h)) (def req (h/request-from-globals)) (h/emit-response (h/response-from-map {:status 200 :headers {"Content-Type" "text/plain"} :body (str "Hello " (:uri req))}))
Macros (defmacro unless [pred & body] `(if (not ~pred) (do ~@body))) (unless (zero? 1) (println "not zero")) ;; => not zero (unless false (println "ok")) ;; => ok	PHP interop (ns app) (def now (php/new \DateTime)) (.format now "Y-m-d") ;; => "2026-04-20" (def epoch (php/new \DateTime "1970-01-01")) (.-days (.diff now epoch)) ;; => 20564

Documentation

• Quick Start: install, REPL, first script (5 min)
• Documentation Index: every guide, grouped by purpose
• phel-lang.org: tutorials, exercises, blog
• Packagist
• CONTRIBUTING.md: setup and workflow
• AGENTS.md: architecture and review expectations

AI Coding Agents

Skill files for Claude Code, Cursor, Codex, Gemini, Copilot, Aider: resources/agents/

./vendor/bin/phel agent-install [platform]   # install skill file for one agent (claude, cursor, ...)
./vendor/bin/phel agent-install --auto       # only agents detected in this project
./vendor/bin/phel agent-install --all        # every supported platform

Repo-level AI tooling

Claude Code (.claude/) and Codex (.codex/, .agents/, AGENTS.md) configs generate from a single source tree under .agnostic-ai/ via agnostic-ai. Those directories are gitignored; run sync after cloning to materialize them. Add more targets (Gemini, Cursor, ...) by appending to targets: in agnostic-ai.yaml.

brew install Chemaclass/tap/agnostic-ai   # or: go install github.com/chemaclass/agnostic-ai/cmd/agnostic-ai@latest
agnostic-ai sync                          # regenerate per-tool configs

Edit specs under .agnostic-ai/{rules,agents,skills,hooks,scripts,overlays}/, then agnostic-ai sync again. A CI gate runs sync --check on every PR to block drift between the source and the (gitignored) emitted files.