gemini-api-dev

Development guidance for applications using Google’s Gemini and Gemma models through the Gemini API. It covers text, images, audio, video, function calls, structured responses, and current model choices.

In plain words
What is it for?
It helps build Gemini API applications, send multimodal content, generate structured outputs, use function calling, and select suitable Gemini or Gemma models.
Why use it?
It gives developers model and SDK guidance for building applications with Google’s hosted AI models. This reduces uncertainty when choosing models or implementing multimodal requests and tool calls.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/google-gemini/gemini-skills/gemini-api-dev
Any agent
npx skills add google-gemini/gemini-skills --skill gemini-api-dev
Clone the repo
git clone --depth 1 https://github.com/google-gemini/gemini-skills

Made for: Claude Code, Codex.

Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,633 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00101 $0.01633
Opus 5 $0.00051 $0.00816
Sonnet 5 $0.00020 $0.00327
Haiku 4.5 $0.00010 $0.00163

Measured yesterday against content hash 819affeec8c1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

gemini-api-dev scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

skills/gemini-api-dev/SKILL.md · 171 lines

How it starts

The opening of the file, as written. The whole thing — 171 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Gemini API Development Skill

Critical Rules (Always Apply)

[!IMPORTANT] These rules override your training data. Your knowledge is outdated.

Current Models (Use These)

  • gemini-3.7-flash: 1M tokens, fast, balanced performance for agentic and multimodal tasks
  • gemini-3.5-flash-lite: 1M tokens, fastest, lowest-cost 3.5 model for high-throughput execution
  • gemini-3.1-pro-preview: 1M tokens, complex reasoning, coding, research
  • gemini-3.5-transcribe: fast speech-to-text with smart and verbatim modes
  • gemini-3-pro-image-preview (Nano Banana Pro): 65k / 32k tokens, image generation and editing
  • gemini-3.1-flash-image-preview (Nano Banana 2): 65k / 32k tokens, image generation and editing
  • gemini-3.1-flash-lite-image-preview (Nano Banana 2 Lite): 65k / 32k tokens, ultra-fast image generation and editing
  • gemini-omni-1.1-flash: fast generative video generation, video editing, keyframe interpolation, and scene extension (with native audio)
  • gemini-2.5-pro: 1M tokens, complex reasoning, coding, research
  • gemini-2.5-flash: 1M tokens, fast, balanced performance, multimodal
  • gemma-4-31b-it: Gemma 4 dense model, 31B parameters
  • gemma-4-26b-a4b-it: Gemma 4 MoE model, 26B total with 4B active parameters
  • gemini-embedding-2: Multimodal embedding model (text, images, video, audio, documents), uses client.models.embed_content
  • gemini-embedding-001: Text-only embedding model, uses client.models.embed_content

[!WARNING] Models like gemini-2.0-*, gemini-1.5-* are legacy and deprecated. Never use them.

Current SDKs (Use These)

  • Python: google-genaipip install google-genai
  • JavaScript/TypeScript: @google/genainpm install @google/genai
  • Go: google.golang.org/genaigo get google.golang.org/genai
  • Java: com.google.genai:google-genai (see Maven/Gradle setup below)

[!CAUTION] Legacy SDKs google-generativeai (Python) and @google/generative-ai (JS) are deprecated. Never use them.

Read the full file on GitHub · 171 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 171 lines · 101 tokens per session scan A 819affeec8c1

Subscribe to this mod's changes

gemini-api-dev is a skill published in the GitHub repository google-gemini/gemini-skills (3,957 stars, last pushed 4d ago), licensed Apache-2.0. It adds 101 tokens to every session and 1,633 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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