Agents SDK

What it does

When your agent uses it

• Tasks that involve MCP servers

Example prompts

• “/agents-sdk”

Requirements

• Node.js

What it can do on your machine

Read from SKILL.md and the folder at commit 41e0d19. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • npm

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • developers.cloudflare.com
  • github.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Agents SDK loads about 3k tokens when it runs, and up to ~12k if it reads all its reference files. Until then it costs about 24 tokens; SKILL.md has 685 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~24

When it runs · the whole SKILL.md, loaded when a task matches

~3k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~12k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from cloudflare/skills at commit 41e0d19, republished under its Apache-2.0 licence (© cloudflare). 685 words, ~3,003 tokens.

name

agents-sdk

description

Build, debug, or review Cloudflare Agents SDK applications using the agents package.

npm ls agents  # Should show agents package

npm install agents

npm install agents @cloudflare/ai-chat ai @ai-sdk/react

{
  "compatibility_flags": ["nodejs_compat"],
  "durable_objects": {
    "bindings": [{ "name": "MyAgent", "class_name": "MyAgent" }]
  },
  "migrations": [{ "tag": "v1", "new_sqlite_classes": ["MyAgent"] }]
}

import { Agent, routeAgentRequest, callable } from "agents";

type State = { count: number };

export class Counter extends Agent<Env, State> {
  initialState = { count: 0 };

  validateStateChange(nextState: State, source: Connection | "server") {
    if (nextState.count < 0) throw new Error("Count cannot be negative");
  }

  onStateUpdate(state: State, source: Connection | "server") {
    console.log("State updated:", state);
  }

  @callable()
  increment() {
    this.setState({ count: this.state.count + 1 });
    return this.state.count;
  }
}

export default {
  fetch: (req, env) => routeAgentRequest(req, env) ?? new Response("Not found", { status: 404 })
};

© cloudflare, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 19 other files (references) in skills/agents-sdk of cloudflare/skills.

• SKILL.md
• references/browse-the-web.md
• references/callable.md
• references/client-sdk.md
• references/codemode.md
• references/configuration.md
• references/durable-execution.md
• references/email.md
• references/human-in-the-loop.md
• references/mcp.md
• references/observability.md
• references/queue-retries.md
• references/routing.md
• references/server-driven-messages.md
• references/state-scheduling.md
• references/streaming-chat.md
• references/think.md
• references/voice.md
• references/webhooks-push.md
• references/workflows.md

Open the folder on GitHubat commit 41e0d19

Used in 2 other repositories

We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 2 other GitHub owners. This page covers the copy in cloudflare/skills, which our catalogue first saw on October 7, 2026.

• softmaple/softmaple.agents/skills/agents-sdk
• fcakyon/claude-codex-settingsplugins/cloudflare-skills/skills/agents-sdk