Skip to main content
Skills give the agent domain expertise on demand. The model sees each skill by name and description, and loads the full instructions only when it decides they are needed — a progressive disclosure pattern described in Designing, Refining, and Maintaining Agent Skills.

Why use skills

  • Specialize. Add document generation and domain workflows on top of base prompting.
  • Pay context only on use. Until a skill is loaded, it costs only its name and description.
  • Compose. Mix built-in skills with inline instructions in one request.

How skills work

You pass a skills array on the request. Each entry is either a built-in selection from the catalog or an inline skill you define for the request. The description is the routing trigger. Write it to tell the model when to load the skill. Skills run on the durable backend. Submit with background: true and poll as shown in Background mode.

Available skills

Built-in skills

Select a built-in skill with one JSON object: { "type": "builtin", "name": "office/pdf" }.

Office

Generate PDF, Word, PowerPoint, and Excel documents from scratch, with structural validation and visual QA. Select a specific leaf, or select office to grant all four at once and let the model pick the format.
Office skills create documents from scratch. They do not edit files you upload.

Inline skills

Use inline skills for one-off or account-specific guidance the model should load on demand: style guides, playbooks, design systems, house rules.
Inline skills have no files, no dependencies, no sandbox mounts, no reusable library, and are never echoed back in the response.

Example

Combine office/pdf with an inline design-system skill to render a house-styled one-page AI-industry stock report.
The output contains a skill_loaded item for each skill the model loaded. Retrieve file bytes through the files endpoints in Working with files.

Next steps

Agent skills cookbook

Full walkthrough of the daily AI stock news PDF, including file download and the complete design book.

Working with files

Background mode

Agent API reference