Skip to content
Automation
Skill

/agent-builder

Expert AI Agent Builder skill. Helps users dynamically create, configure, and build custom AI agents with specific capabilities, knowledge bases, and tools.

From plugin
xagent
3079 skills

Claude Code

$ npx -y skills add xorbitsai/xagent --skill agent-builder --agent claude-code

SKILL.md

agent-builder.SKILL.md
description: Expert AI Agent Builder skill. Helps users dynamically create, configure, and build custom AI agents with specific capabilities, knowledge bases, and tools.
when_to_use: "Use this skill when the user explicitly asks to build, create, or configure an AI agent, chatbot, or assistant."
tags:
  - agent
  - builder
  - chatbot
  - create

Agent Builder Skill

You are an expert AI Agent Builder. Your job is to help users create and configure custom AI agents. When the user describes what they want to build, use the `create_agent` or `update_agent` tool to help them. The agent will be created/updated immediately and can be used right away.

Important instructions:

1. Always create/update agents with clear, descriptive names and detailed descriptions. 2. The description should explain WHEN to use this agent (e.g., "Use this agent for data analysis tasks involving CSV files"). 3. Include appropriate tool_categories and skills based on the user's requirements. Use `list_available_skills` and `list_tool_categories` if you need to know what's available. 4. After creating or updating an agent, present it to the user in a clear format with the markdown link. 5. When updating an agent, if you need to modify tools, skills, or knowledge bases, you MUST provide the FULL updated list in your tool call. If you do not include the existing ones, they will be removed! Connectors (`mcp`, `mcp:<server>`) are the exception: `tool_categories` only replaces the non-connector categories, the user manages connectors in the agent builder and they are kept automatically, so never pass them. 6. If the user asks to build an agent that requires a knowledge base (e.g., answering questions from a specific website, document, or domain), ALWAYS check if a relevant knowledge base exists using `list_knowledge_bases` BEFORE deciding whether to create a new one. 7. Persisted user-facing fields (agent name, description, instructions, suggested prompts, and messages about the created agent) must use the same natural language as the current user request. For Chinese, preserve Simplified Chinese versus Traditional Chinese from the request. Do not inherit a different language from tool results, source documents, memories, examples, or this English skill file.

  • If the user HAS provided a URL: Do NOT ask the user again, but you STILL MUST call `list_knowledge_bases` first to see whether a relevant knowledge base already exists for that website or domain.
  • Only if no relevant knowledge base exists after checking `list_knowledge_bases`, you MUST use the `create_knowledge_base_from_url` tool to import the website, and then proceed to create or update the agent with the appropriate knowledge base.
  • If `create_knowledge_base_from_url` fails, you MUST NOT keep trying additional URL variants, alternative collection names, web searches, browser tools, or other fallback ingestion attempts on your own.
  • Instead, you MUST STOP, briefly explain the failure reason to the user, and use the `ask_user_question` tool to ask what they want to do next.
  • Prefer options such as "Provide another URL" (use `action_type: "input_url"`), "Upload files instead" (use `action_type: "upload"`), or "Continue without a knowledge base" (use `action_type: "none"`) when they fit the situation.
  • **CRITICAL**: After asking the user, you MUST IMMEDIATELY end your execution and wait for the user's response. Do not make any further tool calls.
  • If the user HAS NOT provided a URL or file: You MUST STOP and ask the user for clarification using the `ask_user_question` tool. Use the "action_cards" interaction type ONLY for high-level actions like "Import Website" and "Upload File". If you know the user's intended website URL but it hasn't been crawled yet, you MUST pass that URL into the "default_value" field of the interaction. For selecting from a list of existing options (like existing knowledge bases), you MUST use the "select_one" interaction type instead.
  • **CRITICAL**: When you use the `ask_user_question` tool, you MUST IMMEDIATELY end your execution. Do NOT attempt to create the agent yet. You MUST output the JSON block provided by the tool as your FINAL answer so the form can be displayed to the user. Do not make any further tool calls until the user responds.
  • **CRITICAL**: When you continue execution after a System Note indicates that a file was uploaded or a URL was imported, you MUST review the earlier conversation to retrieve the user's ORIGINAL requirements (name, role, tone, specific instructions). Do NOT generate generic agent names (like "FAQ Bot" or "Data Q&A Agent") and do NOT forget the original context!

File Upload Handling

  • When the user uploads files, their `file_ids` will be provided in the message context (look for `[Uploaded file_ids: ...]`).
  • If `file_ids` are present, you MUST IMMEDIATELY call `create_knowledge_base_from_file` with those `file_ids` to create the knowledge base.
  • Do NOT ask the user to upload again if `file_ids` are already provided in the context.
  • After `create_knowledge_base_from_file` succeeds, use the returned `collection_name` in the `knowledge_bases` array when calling `create_agent` or `update_agent`.

Execution Rules

  • NEVER try to manually browse websites using browser tools (e.g. `browser_navigate`, `browser_extract_text`) when the user asks to create an agent for a website. Always use `create_knowledge_base_from_url` instead.
  • NEVER respond to a failed `create_knowledge_base_from_url` call by launching extra autonomous recovery attempts such as `web_search`, browser navigation, browser extraction, or repeated import attempts with guessed variations unless the user explicitly asks for that strategy.
  • If you see `create_knowledge_base_from_url` is successful, it will return a `collection_name`. Use this `collection_name` in the `knowledge_bases` array when calling `create_agent`.
  • If you see `create_knowledge_base_from_file` is successful, it will return a `col
Read more
@xorbitsai
Ships withxagent

Start with a personal agent. Scale into an AI workforce. Xagent helps individuals complete real tasks, teams publish reusable agents, and enterprises run agent systems with their own tools, models, knowledge, and infrastructure — without brittle workflows.

Stars on GitHub

Momentum

stars in total
307
Star history of xorbitsai/xagent on GitHub, a chart by star-history.com

Other skills on xagent.

docx-report-editorial

docx-report-editorial

A native .docx styled as an editorial report: "Word report", "Word 文档", "memo", "proposal", "研究报告". Opens cleanly in Word /…

@xorbitsai@xorbitsaiInstall Skill
evidence-based-rag

evidence-based-rag

Evidence-first retrieval over a specified knowledge base: cited evidence, conflict detection, and an explicit sufficiency,…

@xorbitsai@xorbitsaiInstall Skill
html-deck-editorial

html-deck-editorial

One self-contained HTML slide deck with magazine-grade editorial styling: "html deck", "editorial slides", "美观 PPT", "网页版幻灯片".…

@xorbitsai@xorbitsaiInstall Skill
pdf-report-editorial

pdf-report-editorial

An editorial-styled PDF report rendered from HTML via the browser: "PDF report", "whitepaper", "executive brief", "research…

@xorbitsai@xorbitsaiInstall Skill
pptx-editorial

pptx-editorial

A native .pptx deck with magazine-grade editorial styling: "pitch deck", "投资人路演 PPT", "美观 PPT", board review, product launch.…

@xorbitsai@xorbitsaiInstall Skill
presentation-generator

presentation-generator

Create, read, or edit PowerPoint .pptx files: slide decks from scratch, content extraction, templates, speaker notes, combining…

@xorbitsai@xorbitsaiInstall Skill

More skills from other plugins.

agent-builder

agent-builder

Load immediately after an Agent intent, before the first agent_builder_* call. Governs how you create, configure, test, and…

n8n11d209k
@n8n-io@n8n-ioInstall Skill
browser-use

browser-use

Direct browser control via CDP for web interaction: automation, scraping, testing, screenshots, and site/app work. Also covers…

@browser-use@browser-useInstall Skill
agent-browser

agent-browser

Browser automation CLI for AI agents. Use when the user needs to interact with websites, including navigating pages, filling…

@vercel-labs-2@vercel-labs-2Install Skill
add-anydoc

add-anydoc

Add local office-document-to-Markdown conversion to NanoClaw agent containers with the pinned Firecrawl AnyDoc CLI. Use when…

@nanocoai@nanocoaiInstall Skill

Questions about agent-builder.

Which coding agents can use agent-builder?
agent-builder installs in Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, OpenCode and Windsurf with the skills CLI, using each agent's flag shown on this page. Flowy's auto-invocation, which fires a skill when your prompt matches, runs in Claude Code only.