A Claude skill is a portable file (ending in .skill) that teaches Claude how to perform a specific task. Install one into your Claude app and Claude picks up a new ability - no prompting, no setup, no instructions to copy-paste every time. Skills work in Claude Cowork and Codex.
It's the difference between telling someone how to cook a recipe from scratch every time you want dinner, versus just handing them the cookbook.
How are skills different from prompts or custom instructions?
Before skills existed, there were basically two ways to get Claude to do something specific:
Prompts - you write out exactly what you want every time. Works fine for one-off things, gets old fast when you need the same behavior repeatedly.
Custom instructions - you set some persistent context that Claude remembers across conversations. Better, but it's pretty limited. You can't include schemas, API calls, or complex logic.
Skills sit a level above both. A .skill file bundles instructions, data schemas, API connections, and reference docs into one package. Install it once, and Claude just knows what to do.
| Approach | Persistence | Complexity | Portability |
|---|---|---|---|
| Prompt | Per-conversation | Low | Copy-paste |
| Custom instructions | Persistent | Medium | Not shareable |
| Skill | Per-session | High | A file you can share |
Where do Claude skills work?
Two places right now:
Claude Cowork - Anthropic's collaborative workspace. You chat with Claude, share files, work on stuff together. Skills will be triggered by certain keywords (like "Create my trip").
Codex - the coding environment. Developers use skills here for things like deployment workflows, code patterns, or API integrations.
What's inside a skill file?
A .skill file is a bundle. Depending on the skill, it might contain:
- Instructions - what Claude should do and how to do it
- Schemas - the shape of data Claude needs to produce
- API connections - endpoints Claude can hit to send or receive data
- Reference docs - examples and documentation Claude can lean on
Once installed, Claude reads all of it. You don't have to explain anything. Just ask Claude to do the thing, and it knows how.
What kind of stuff can skills do?
The ecosystem is still early but growing fast. A few categories:
Travel - the OurTrips skill takes any travel conversation and turns it into a proper shareable itinerary. Plan your trip, say "send it to OurTrips," and you get a rich mobile-friendly page with your full day-by-day plan.
Productivity - skills that generate reports, format documents, create presentations. Instead of explaining the output format every single time, the skill just handles it.
Development - code generation with specific patterns, deployment pipelines, database migrations. The skill bakes in best practices so Claude follows them without being told.
Data - structured extraction, analysis workflows, formatted outputs for specific tools or dashboards.
How to install a Claude skill
It takes 30 seconds. Two options:
Just ask Claude to grab it
If your session has internet access:
Fetch https://ourtrips.to/our-trips.skill and add it to my skills.
Claude downloads it, installs it, done.
Or upload it yourself
- Download the
.skillfile - Open Customize in your Cowork settings
- Hit Add skill, pick the file
Where to find Claude skills
Still early days, but there are a few places:
- Directly from creators - lots of tools publish their own skills (like OurTrips)
- Directories - agentskills.so and mcpmarket.com list available skills
- GitHub - developers share skills in repos and Claude communities
- Build your own - if you have a workflow you repeat often, you can package it as a skill
Why Claude skills matter
The big deal with skills is that they lower the bar. You don't need to be good at prompt engineering to get good output from Claude. Someone else already did that work and packaged it into a file you can install.
A few things that follow from that:
- Anyone can use them. Non-technical people get access to complex workflows by dragging in a file.
- Output is consistent. The skill defines the format, so you get the same quality every time.
- They're shareable. Send the file to a friend. They get the exact same capability.
- They stack. Install multiple skills in one session and Claude can use all of them.
Try one
Easiest way to get it is to just do it:
- Open a Claude Cowork session
- Tell Claude:
Fetch https://ourtrips.to/our-trips.skill and add it to my skills. - Plan a trip
- Say "Send it to OurTrips"
- Open the link
Experience the magic :)