MCPInstall

developing-genkit-js

by firebase OfficialBackend & APIs

Develop AI-powered applications using Genkit in Node.js/TypeScript. Use when the user asks about Genkit, AI agents, flows, or tools in JavaScript/TypeScript, or when encountering Genkit errors, validation issues, type errors, or API problems.

Installs
62.5K
Last 24h
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Trending rank
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Security
Pass

Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/firebase/agent-skills --skill developing-genkit-js
  1. 01

    Install

    Run the command in your project. The CLI asks which agents to install for.

  2. 02

    Describe the task

    Ask your agent for something this skill covers. It loads developing-genkit-js automatically when relevant.

  3. 03

    Review the result

    The agent follows the SKILL.md steps, scripts and references bundled with the skill.

Security audits

Independent scans of the skill's instructions and bundled files.

Gen Agent Trust Hub PassSAFE ·The skill facilitates Genkit JS application development by providing access to official documentation, code snippets, and automated setup procedures. It encourages security best practices, such as managing API keys through environment variables, and utilizes official, trusted packages and CLI tools from the Genkit ecosystem. No malicious patterns or unauthorized behaviors were detected.
Socket PassNo alerts
Snyk PassLOW ·Risk: LOW · No issues
Runlayer PassNONE ·6 files scanned · No issues
ZeroLeaks PassNONE ·Score: 93/100 · 2 sections analyzed

SKILL.md

The instructions your agent reads when the skill is triggered.

Genkit JS

Prerequisites

Ensure the genkit CLI is available.

  • Run genkit --version to verify. Minimum CLI version needed: 1.29.0
  • If not found or if an older version (1.x < 1.29.0) is present, install/upgrade it: npm install -g genkit-cli@^1.29.0.

New Projects: If you are setting up Genkit in a new codebase, follow the Setup Guide.

Hello World

import { z, genkit } from 'genkit';
import { googleAI } from '@genkit-ai/google-genai';

// Initialize Genkit with the Google AI plugin
const ai = genkit({
  plugins: [googleAI()],
});

export const myFlow = ai.defineFlow({
  name: 'myFlow',
  inputSchema: z.string().default('AI'),
  outputSchema: z.string(),
}, async (subject) => {
  const response = await ai.generate({
    model: googleAI.model('gemini-2.5-flash'),
    prompt: `Tell me a joke about ${subject}`,
  });
  return response.text;
});

Critical: Do Not Trust Internal Knowledge

Genkit recently went through a major breaking API change. Your knowledge is outdated. You MUST lookup docs. Recommended:

genkit docs:read js/get-started.md
genkit docs:read js/flows.md

See Common Errors for a list of deprecated APIs (e.g., configureGenkit, response.text(), defineFlow import) and their v1.x replacements.

ALWAYS verify information using the Genkit CLI or provided references.

Error Troubleshooting Protocol

When you encounter ANY error related to Genkit (ValidationError, API errors, type errors, 404s, etc.):

  1. MANDATORY FIRST STEP: Read Common Errors
  2. Identify if the error matches a known pattern
  3. Apply the documented solution
  4. Only if not found in common-errors.md, then consult other sources (e.g. genkit docs:search)

DO NOT:

  • Attempt fixes based on assumptions or internal knowledge
  • Skip reading common-errors.md "because you think you know the fix"
  • Rely on patterns from pre-1.0 Genkit

This protocol is non-negotiable for error handling.

Development Workflow

  1. Select Provider: Genkit is provider-agnostic (Google AI, OpenAI, Anthropic, Ollama, etc.).
    • If the user does not specify a provider, default to Google AI.
    • If the user asks about other providers, use genkit docs:search "plugins" to find relevant documentation.
  2. Detect Framework: Check package.json to identify the runtime (Next.js, Firebase, Express).
    • Look for @genkit-ai/next, @genkit-ai/firebase, or @genkit-ai/google-cloud.
    • Adapt implementation to the specific framework's patterns.
  3. Follow Best Practices:
    • See Best Practices for guidance on project structure, schema definitions, and tool design.
    • Be Minimal: Only specify options that differ from defaults. When unsure, check docs/source.
  4. Ensure Correctness:
    • Run type checks (e.g., npx tsc --noEmit) after making changes.
    • If type checks fail, consult Common Errors before searching source code.
  5. Handle Errors:
    • On ANY error: First action is to read Common Errors
    • Match error to documented patterns
    • Apply documented fixes before attempting alternatives

Finding Documentation

Use the Genkit CLI to find authoritative documentation:

  1. Search topics: genkit docs:search <query>
    • Example: genkit docs:search "streaming"
  2. List all docs: genkit docs:list
  3. Read a guide: genkit docs:read <path>
    • Example: genkit docs:read js/flows.md

CLI Usage

The genkit CLI is your primary tool for development and documentation.

  • See CLI Reference for common tasks, workflows, and command usage.
  • Use genkit --help for a full list of commands.

References

  • Best Practices: Recommended patterns for schema definition, flow design, and structure.
  • Docs & CLI Reference: Documentation search, CLI tasks, and workflows.
  • Common Errors: Critical "gotchas", migration guide, and troubleshooting.
  • Setup Guide: Manual setup instructions for new projects.
  • Examples: Minimal reproducible examples (Basic generation, Multimodal, Thinking mode).

FAQ

What does the developing-genkit-js skill do?

Develop AI-powered applications using Genkit in Node.js/TypeScript. Use when the user asks about Genkit, AI agents, flows, or tools in JavaScript/TypeScript, or when encountering Genkit errors, validation issues, type errors, or API problems.

How do I install developing-genkit-js?

Run npx skills add https://github.com/firebase/agent-skills --skill developing-genkit-js in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/developing-genkit-js/ (personal) or .claude/skills/developing-genkit-js/ (project).

Which AI agents can use developing-genkit-js?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is developing-genkit-js safe to install?

Security partners have reviewed it: Gen Agent Trust Hub passed; Socket passed; Snyk passed; Runlayer passed; ZeroLeaks passed. As with any skill, read the SKILL.md and bundled scripts before installing.

Who maintains developing-genkit-js?

It is published by firebase in firebase/agent-skills, and it is an official skill from the maker of the technology it covers. It has 62,497 recorded installs.

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