Update README.md for improved structure and clarity

README.md

@@ -1,31 +1,259 @@
-# Gemini API examples
+# Gemini API Examples
 
-This repository contains example code for key features of the Gemini API. The
-repo is organized by programming language.
+This repository contains example code for key features of the Gemini API.
+The repo is organized by programming language.
 
 The examples are embedded in the
-[Gemini API reference](https://ai.google.dev/api) and other places in the
-developer documentation.
+[Gemini API reference](https://ai.google.dev/api) and other places in the developer documentation.
+Every example is:
 
-Each file is structured as a runnable test case, ensuring that examples are
-executable and functional. Each test demonstrates a single concept and contains
-special comments called _region tags_ that demarcate the test scaffolding from
-the example code snippet. Here's a Python example:
+* **Runnable** — all examples execute as real tests or standalone scripts
+* **Minimal & pedagogical** — each file teaches one concept
+* **Multi-language** — Go, Java, JavaScript/TypeScript, Python, and REST
+* **Documentation-aware** — region tags allow automatic snippet extraction
+* **Kept up-to-date** with evolving Gemini features
 
-```python
-def test_text_gen_text_only_prompt(self):
-    # [START text_gen_text_only_prompt]
-    from google import genai
 
-    client = genai.Client()
-    response = client.models.generate_content(
-        model="gemini-2.0-flash", contents="Write a story about a magic backpack."
-    )
-    print(response.text)
-    # [END text_gen_text_only_prompt]
+# **Repository Structure**
+
+```
+api-examples/
+├── go/                # Go examples + tests
+├── java/              # Java examples (Maven project)
+├── javascript/        # JS/TS examples + tests
+├── python/            # Python runnable examples
+├── rest/              # cURL-style shell examples
+├── third_party/       # Multimedia files for multimodal examples
+├── CONTRIBUTING.md
+├── LICENSE
+└── README.md          # (this file)
+```
+
+Each language folder includes:
+
+* Example files (e.g., `chat.go`, `embed.py`, `text_generation.js`)
+* Matching tests (e.g., `chat_test.go`, `chat.test.js`)
+* Language-specific README instructions
+
+
+# **What’s Included**
+
+The repository covers a wide set of Gemini capabilities:
+
+## **Core Text & Chat**
+
+* Text generation
+* Thinking mode
+* Controlled generation
+* Chat sessions
+* System instructions
+* Safety settings
+
+## **Structured & Programmatic Generation**
+
+* Function calling
+* Code execution
+
+## **Data & Tokens**
+
+* Embeddings
+* Token counting
+* File uploads & retrieval
+
+## **Advanced Features**
+
+* Grounding
+* Model parameter configuration
+* Caching
+
+## **Multimodal**
+
+* Examples using images, videos, and audio (in `third_party/`)
+
+
+# **Quickstart by Language**
+
+Below are short, ready-to-run instructions for each language folder.
+
+
+## **Go**
+
+### Install & Run
+
+```bash
+cd go
+go mod tidy
+export GOOGLE_API_KEY="YOUR_KEY"
+go test ./...
+```
+
+Each example is a Go test file such as `chat_test.go`, `code_execution_test.go`, etc.
+
+
+## **Java**
+
+### Set Up
+
+1. Ensure you have a Java JDK (version 11 or higher) and Maven installed
+2. Open the `java/` folder in your preferred IDE or command line
+3. Run `mvn clean install` to download dependencies
+
+### Set API Key
+
+Export the API key to your environment:
+
+```bash
+export GOOGLE_API_KEY="YOUR_KEY"
+```
+
+### Run a Test
+
+```bash
+mvn -Dtest=<TestClassName> test
+```
+
+Example:
+
+```bash
+mvn -Dtest=CodeExecutionTest test
+```
+
+
+## **JavaScript / TypeScript**
+
+### Install
+
+```bash
+cd javascript
+npm install
+export GOOGLE_API_KEY="YOUR_KEY"
+```
+
+### Run Tests
+
+```bash
+npm test
 ```
 
-The API reference can be configured to show the code between the region tags.
+To run a specific test file:
+
+```bash
+node <feature>.test.js
+```
+
+Example:
+
+```bash
+node text_generation.test.js
+```
+
+### Format Code
+
+```bash
+npm run format
+```
+
+---
+
+## **Python**
+
+### Install
+
+```bash
+cd python
+pip install absl-py google-genai Pillow pyink
+export GOOGLE_API_KEY="YOUR_KEY"
+```
+
+### Run an Example
+
+```bash
+python <filename>.py
+```
+
+Example:
+
+```bash
+python text_generation.py
+```
+
+### Format Code
+
+```bash
+pyink .
+```
+
+
+## **REST (Shell)**
+
+```bash
+cd rest
+export GOOGLE_API_KEY="YOUR_KEY"
+./embed.sh
+```
+
+
+# **Region Tags**
+
+All examples use **region tags** that enable automated extraction into Gemini documentation.
+
+```python
+# [START gemini_text_gen]
+response = client.generate_text("Hello!")
+# [END gemini_text_gen]
+```
+
+When contributing examples:
+
+* Region tags **must** remain correctly paired
+* Only example code should be inside the tags
+* Test scaffolding should remain outside
+
+This keeps documentation perfectly aligned with working code.
+
+
+# **Testing Philosophy**
+
+Every example in this repo is **automatically verified**.
+
+* **Go** → `go test`
+* **Java** → `mvn test`
+* **JavaScript/TypeScript** → Node test files
+* **Python** → runnable scripts
+* **REST** → executable shell scripts
+
+Tests ensure examples remain:
+
+* Correct
+* Up-to-date
+* Documentation-ready
+* Idiomatic for each language
+
+
+# **Contributing**
+
+If you're contributing, please ensure that code inside region tags follows best practices:
+
+* **Clear** — easy for beginners to understand
+* **Complete** — runnable with minimal setup
+* **Concise** — no unnecessary lines
+
+### You can contribute by:
+
+* Adding missing examples
+* Enhancing clarity of existing examples
+* Expanding test coverage
+* Adding new model features
+* Improving region tags
+* Submitting bug fixes
+* Improving language-specific READMEs
+
+### PR Checklist
+
+Before submitting:
 
-If you're contributing, please make sure that the code within region tags
-follows best practices for example code: clear, complete, and concise.
+* Code runs successfully
+* Region tags are correct
+* Tests are added or updated
+* Code is minimal & idiomatic
+* Commit message is descriptive