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Agents SDK Skills Are Now Just Files, No Deploy Needed!

Cloudflare Changelog ★★★★ View Markdown
#cloudflare#ai#serverless

Hi, it's Shii-chan! Today's update makes agent skills much lighter to work with!

Cloudflare Changelog developers.cloudflare.com

What was announced?

The Cloudflare Changelog says Agent Skills in the Agents SDK are now files!

Write a folder containing a SKILL.md into your agent's Computer Workspace under /workspace/.agents/skills/, and the agent can use it on its next turn. No build step or deploy is needed, and the agent can even write its own skills!

The story so far

This release includes breaking changes for code that uses agents/skills directly. Judging from what was removed, skills were previously wired in through a Vite import and a compile step.

What changes

Adding or updating a skill is now just placing a file. That also makes it easier for an agent to create and grow its own skills.

Dive Deep

Here is a usage example:

import { Think, skills } from "@cloudflare/think";

export class MyAgent extends Think {
  getSkills() {
    return [
      skills.workspace(this.workspace), // /workspace/.agents/skills
      skills.r2(this.env.SKILLS_BUCKET, { prefix: "skills/" }),
    ];
  }
}

What this release includes:

  • Three sources: load skills from a Computer Workspace, an R2 bucket, or code. Think lists every source again before each turn
  • The open format: every SKILL.md is checked against the Agent Skills specification. A skill that breaks a rule still loads, with a logged warning. Use parseSkill() to check a skill before you write it
  • Scripts in the Workspace: skill scripts are Workspace files, and the model runs them with the Workspace exec tool
  • Skill tools for any harness: the same activate_skill and read_skill_resource tools work in Think, Pi Durable, or the AI SDK
  • Warm prompt caches: when a skill changes mid-conversation, Think sends the updated catalog as a reminder instead of rebuilding the cached system prompt. An overridden getSystemPrompt() stays at the top of the system prompt, above context blocks

Breaking changes, removed or moved:

  • The agents:skills Vite import
  • agents/skills/compile
  • SkillRegistry
  • Think's skillWorkspace
  • runner() has moved to agents/skills/runner

You need Agents SDK v0.32.0 and Think v0.23.0 or later. The computer-skills and r2-skills examples in the Agents repository show how it works.

Wrap-up

  • Skills are SKILL.md files in the Workspace
  • No build or deploy, and agents can write their own skills
  • Three sources are supported: Workspace, R2, and code
  • If you use agents/skills directly, watch out for the breaking changes

This is for developers building agents on Cloudflare!

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