diff --git a/README.md b/README.md
index 6464118..130a072 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ increments version by git log message contexts.
 
 [semver workflow of this repository](https://github.com/rinx/gitwerk/blob/master/.github/workflows/semver.yml) is an example of this subcommand.
 
-```
+```bash
 ## when the latest tag is v0.0.1
 $ git commit -m "[patch] increment patch version"
 ## the commit comment contains "[patch]"
@@ -64,7 +64,7 @@ $ gitwerk semver-auto
 
 prints incremented version.
 
-```
+```bash
 ## when the latest tag is v0.0.1
 
 $ gitwerk semver patch
@@ -81,7 +81,7 @@ v1.0.0
 
 gitwerk supports to run user-defined scripts written in clojure (powered by [borkdude/sci](https://github.com/borkdude/sci)).
 
-```
+```bash
 ## can read stdin
 $ echo '(semver ctx ["patch"])' | gitwerk sci
 v0.0.2
@@ -107,6 +107,12 @@ Version not updated
 $ git commit --allow-empty -m "[patch] version updated"
 $ gitwerk sci examples/example2.clj
 Version updated: v0.0.3 -> v0.0.4
+
+## http get/post using clj-http-lite.client
+$ echo '(-> (http/get "https://api.github.com/repos/rinx/gitwerk/issues") pprint)' | gitwerk sci
+
+## parse json and convert to clj map
+$ echo '(-> (http/get "https://api.github.com/repos/rinx/gitwerk/issues") :body (json/read-value) pprint)' | gitwerk sci
 ```
 
 ## License
diff --git a/src/gitwerk/command/sci.clj b/src/gitwerk/command/sci.clj
index 1252791..c329b5c 100644
--- a/src/gitwerk/command/sci.clj
+++ b/src/gitwerk/command/sci.clj
@@ -2,12 +2,20 @@
   (:require
    [clojure.spec.alpha :as spec]
    [clojure.pprint :as pprint]
+   [clojure.edn :as edn]
    [sci.core :as sci]
-   [gitwerk.internal.io :as internal.io]))
+   [clj-http.lite.client :as http]
+   [gitwerk.internal.io :as internal.io]
+   [gitwerk.internal.json :as json]))
 
 (def clj-primitives
   {'println println
-   'pprint pprint/pprint})
+   'pprint pprint/pprint
+   'json/read-value json/read-value
+   'edn/read-string edn/read-string
+   'env #(or (System/getenv %) "")
+   'http/get http/get
+   'http/post http/post})
 
 (defn run-fn [sci-opts]
   (fn [ctx args]