Gemini API Dev

1---
2name: gemini-api-dev
3description: Use this skill when building applications with Gemini models, Gemini API, working with multimodal content (text, images, audio, video), implementing function calling, using structured outputs, or needing current model specifications. Covers SDK usage (google-genai for Python, @google/genai for JavaScript/TypeScript, com.google.genai:google-genai for Java, google.golang.org/genai for Go), model selection, and API capabilities.
4---
5 
6# Gemini API Development Skill
7 
8## Overview
9 
10The Gemini API provides access to Google's most advanced AI models. Key capabilities include:
11- **Text generation** - Chat, completion, summarization
12- **Multimodal understanding** - Process images, audio, video, and documents
13- **Function calling** - Let the model invoke your functions
14- **Structured output** - Generate valid JSON matching your schema
15- **Code execution** - Run Python code in a sandboxed environment
16- **Context caching** - Cache large contexts for efficiency
17- **Embeddings** - Generate text embeddings for semantic search
18 
19## Current Gemini Models
20 
21- `gemini-3-pro-preview`: 1M tokens, complex reasoning, coding, research
22- `gemini-3-flash-preview`: 1M tokens, fast, balanced performance, multimodal
23- `gemini-3-pro-image-preview`: 65k / 32k tokens, image generation and editing
24 
25 
26> [!IMPORTANT]
27> Models like `gemini-2.5-*`, `gemini-2.0-*`, `gemini-1.5-*` are legacy and deprecated. Use the new models above. Your knowledge is outdated.
28 
29## SDKs
30 
31- **Python**: `google-genai` install with `pip install google-genai`
32- **JavaScript/TypeScript**: `@google/genai` install with `npm install @google/genai`
33- **Go**: `google.golang.org/genai` install with `go get google.golang.org/genai`
34- **Java**:
35  - groupId: `com.google.genai`, artifactId: `google-genai`
36  - Latest version can be found here: https://central.sonatype.com/artifact/com.google.genai/google-genai/versions (let's call it `LAST_VERSION`) 
37  - Install in `build.gradle`:
38    ```
39    implementation("com.google.genai:google-genai:${LAST_VERSION}")
40    ```
41  - Install Maven dependency in `pom.xml`:
42    ```
43    <dependency>
44	    <groupId>com.google.genai</groupId>
45	    <artifactId>google-genai</artifactId>
46	    <version>${LAST_VERSION}</version>
47	</dependency>
48    ```
49 
50> [!WARNING]
51> Legacy SDKs `google-generativeai` (Python) and `@google/generative-ai` (JS) are deprecated. Migrate to the new SDKs above urgently by following the Migration Guide.
52 
53## Quick Start
54 
55### Python
56```python
57from google import genai
58 
59client = genai.Client()
60response = client.models.generate_content(
61    model="gemini-3-flash-preview",
62    contents="Explain quantum computing"
63)
64print(response.text)
65```
66 
67### JavaScript/TypeScript
68```typescript
69import { GoogleGenAI } from "@google/genai";
70 
71const ai = new GoogleGenAI({});
72const response = await ai.models.generateContent({
73  model: "gemini-3-flash-preview",
74  contents: "Explain quantum computing"
75});
76console.log(response.text);
77```
78 
79### Go
80```go
81package main
82 
83import (
84	"context"
85	"fmt"
86	"log"
87	"google.golang.org/genai"
88)
89 
90func main() {
91	ctx := context.Background()
92	client, err := genai.NewClient(ctx, nil)
93	if err != nil {
94		log.Fatal(err)
95	}
96 
97	resp, err := client.Models.GenerateContent(ctx, "gemini-3-flash-preview", genai.Text("Explain quantum computing"), nil)
98	if err != nil {
99		log.Fatal(err)
100	}
101 
102	fmt.Println(resp.Text)
103}
104```
105 
106### Java
107 
108```java
109import com.google.genai.Client;
110import com.google.genai.types.GenerateContentResponse;
111 
112public class GenerateTextFromTextInput {
113  public static void main(String[] args) {
114    Client client = new Client();
115    GenerateContentResponse response =
116        client.models.generateContent(
117            "gemini-3-flash-preview",
118            "Explain quantum computing",
119            null);
120 
121    System.out.println(response.text());
122  }
123}
124```
125 
126## API spec (source of truth)
127 
128**Always use the latest REST API discovery spec as the source of truth for API definitions** (request/response schemas, parameters, methods). Fetch the spec when implementing or debugging API integration:
129 
130- **v1beta** (default): `https://generativelanguage.googleapis.com/$discovery/rest?version=v1beta`  
131  Use this unless the integration is explicitly pinned to v1. The official SDKs (google-genai, @google/genai, google.golang.org/genai) target v1beta.
132- **v1**: `https://generativelanguage.googleapis.com/$discovery/rest?version=v1`  
133  Use only when the integration is specifically set to v1.
134 
135When in doubt, use v1beta. Refer to the spec for exact field names, types, and supported operations.
136 
137## How to use the Gemini API
138 
139For detailed API documentation, fetch from the official docs index:
140 
141**llms.txt URL**: `https://ai.google.dev/gemini-api/docs/llms.txt`
142 
143This index contains links to all documentation pages in `.md.txt` format. Use web fetch tools to:
144 
1451. Fetch `llms.txt` to discover available documentation pages
1462. Fetch specific pages (e.g., `https://ai.google.dev/gemini-api/docs/function-calling.md.txt`)
147 
148### Key Documentation Pages 
149 
150> [!IMPORTANT]
151> Those are not all the documentation pages. Use the `llms.txt` index to discover available documentation pages
152 
153- [Models](https://ai.google.dev/gemini-api/docs/models.md.txt)
154- [Google AI Studio quickstart](https://ai.google.dev/gemini-api/docs/ai-studio-quickstart.md.txt)
155- [Nano Banana image generation](https://ai.google.dev/gemini-api/docs/image-generation.md.txt)
156- [Function calling with the Gemini API](https://ai.google.dev/gemini-api/docs/function-calling.md.txt)
157- [Structured outputs](https://ai.google.dev/gemini-api/docs/structured-output.md.txt)
158- [Text generation](https://ai.google.dev/gemini-api/docs/text-generation.md.txt)
159- [Image understanding](https://ai.google.dev/gemini-api/docs/image-understanding.md.txt)
160- [Embeddings](https://ai.google.dev/gemini-api/docs/embeddings.md.txt)
161- [Interactions API](https://ai.google.dev/gemini-api/docs/interactions.md.txt)
162- [SDK migration guide](https://ai.google.dev/gemini-api/docs/migrate.md.txt)
163