Custom Skills

A custom skill is a set of written instructions (a SKILL.md file) that teaches CloudThinker your team’s way of doing a job, such as a review checklist, an escalation order, or a tagging convention. You write it once in More → Workspace settings → Skills, and agents apply it wherever you make it available, so nobody retypes the same rule into every prompt.

When to write a skill

Write a skill when you catch yourself repeating the same instruction. Some typical ones:

Area	Example rule a skill can carry
Review	”Flag any SQL built with string concatenation. Require parameterized queries.”
Incident	”Check the load balancer and the database before the application pods.”
Cloud operations	”Every resource needs `team`, `env`, and `cost-center` tags.”
Reports	”Summarize in three sections: wins, blockers, next steps.”

A skill tells agents how to act; reference material to look up belongs in the knowledge base. See when to use a skill.

Prerequisites

The right role for your method. Developers and Viewers can read skills but don’t see the + button or New Skill. See roles.

Method	Who can use it
Write skill instructions, Upload zip file, edit, delete	Workspace Admin
Create with CloudThinker (`/create-skill` in chat)	Any member who can chat (Admin or Developer)
Skills Hub install link	Any workspace member

If you plan to write SKILL.md by hand or upload a package, skim skill format.

Create a skill

Open Skills

Go to More → Workspace settings → Skills. The page lists your workspace’s skills on the left and shows the selected skill on the right.

Open the new skill menu

Click the + button next to Search skills, at the top of the skills list. (With no skills yet, the page shows a New Skill button instead.) Pick one of the creation methods from the menu. Use the tabs below for the one you chose.

Create the skill

Create with CloudThinker
Write skill instructions
Upload zip file
Browse Skills Hub

Best for a first skill. CloudThinker interviews you and drafts the file.

Click Create with CloudThinker. A chat opens with the /create-skill command filled in.
Send it, then answer the questions. Describe one concrete rule your team applies, with an example.
Review the draft CloudThinker proposes. When it asks Proceed with creating this skill?, pick Yes, create it, or pick Change something and say what to change. Then open More → Workspace settings → Skills to confirm the skill is there, enabled and available in Chat.

You can start the same flow from any chat by typing /create-skill. It’s a normal chat, so it uses credits. Nothing is saved until you pick Yes, create it, so leaving midway leaves no half-made skill.

Best when you already know the exact rules.

Click Write skill instructions.
Fill in the form:

Field	What to enter
Skill name	Starts with a letter or digit; then letters, digits, `_`, or `-`. Example: `weekly-status-report`. Up to 255 characters.
Description (required)	When agents should use the skill. Example: “Generate weekly status reports. Use when asked for updates or progress summaries.” Always fill it in: agents pick skills by description, and CloudThinker can’t save a skill without one. Up to 2,000 characters.
Instructions	The rules, in Markdown. Up to 50,000 characters.

Click Create.

A complete example you can paste, used again under Test the skill:

Skill name: weekly-status-report
Description: Generate weekly status reports. Use when asked for updates or progress summaries.
Instructions:

# Weekly status report

Write the report in exactly three sections, in this order:

## Wins
What shipped or finished this week. One bullet per item, with the owner.

## Blockers
What is stuck, why, and who can unblock it. Write "None" if nothing is blocked.

## Next steps
What the team will do next week. One bullet per item, with the owner.

Keep the whole report under 200 words. No other sections.

Best for skills you keep in a repository or share between workspaces.

Click Upload zip file.
Drop a .zip that contains SKILL.md. See zip package layout for the folders and limits.
Click Upload.

If the zip’s file name matches an existing skill (for example weekly-status-report.zip), CloudThinker asks whether to Replace it. Replace deletes the old skill and uploads the new one, so the switch goes back on and Available in resets to Chat only. Re-tick any other surfaces afterwards. On Scale and above, Audit Logs keep both the delete and the upload. Either way, the old files and settings are gone.The match is on the zip’s file name, exactly, including case. If the zip name matches an existing skill but its frontmatter name differs, Replace still deletes the matched skill, then uploads the new one under the frontmatter name.

Success state: the skill appears in the list with its switch on and Chat checked under Available in.

Choose where the skill applies

A new skill starts enabled and available in Chat only. The other areas stay off until you turn them on, so a half-tested rule can’t change your reviews or incident work.

Select the skill

In More → Workspace settings → Skills, click the skill in the list.

Check the areas under Available in

Tick each place the skill should apply:

Option	Where agents use it
Chat	Workspace chat, plus automations and webhooks
Review	Every merge request and pull request CloudThinker reviews in this workspace, in every connected repository, whether the review started on its own or from an `@cloudthinker-ai review` comment. See Review.
Incident	Incident analysis and root cause investigation in Resolve
Assessment	Well-architected and posture assessments

To pause a skill, use the switch rather than unticking every box.

Review has no per-repository filter. Ticking it applies the skill to the next review in every repository. Test the skill in Chat first, then follow the Review test under Test the skill.

Confirm the switch is on

The switch next to the skill name enables or disables it. A disabled skill stays saved but no agent uses it.

Test the skill

Run a task where the rule matters

Try both ways, each in a new chat. For the weekly-status-report example from the Write skill instructions tab:Run it by name (type / and pick it from the menu):

/weekly-status-report Notes: shipped the new login page (Ana). Billing export blocked on finance sign-off (Raj). Next week: start the search rewrite (Ana).

Run it without naming it:

Write a status update for the platform team from these notes: shipped the new login page (Ana). Billing export blocked on finance sign-off (Raj). Next week: start the search rewrite (Ana).

Paste notes like these so the agent has real content. Without them, or a connected tracker, it has nothing to report and may ask questions instead. Expect three sections, Wins, Blockers, and Next steps, each with one bullet and an owner.Success state: the agent’s activity shows a Load Skill step, and both answers follow the skill (here, the wins, blockers, next steps layout) without you restating the rule.

Widen it once it works

After a few good results in Chat, tick Review, Incident, or Assessment and check the next run there. Review has no sandbox, so test it like this:

Tick Review.
Open a small pull request in a scratch repository that Review covers. Don’t open it as a draft: drafts aren’t reviewed until they’re marked ready. Or comment @cloudthinker-ai review on an existing pull request.
Check the review follows the skill. If it doesn’t, untick Review right away, since every repository uses the skill while it’s ticked.

The CloudThinker app must be installed on that repository; see Review setup and mention commands.

If the output ignores the rule, make the rule more specific and add a good and a bad example. Vague guidance such as “follow our style” rarely changes results.

Edit, download, or delete a skill

Select the skill, then use the icon buttons next to Available in. Hover one to see its name.

Action	How	Notes
Edit with CloudThinker	Pencil icon (Edit skill) → CloudThinker	Opens a chat that loads the skill and helps you refine it.
Edit by hand	Pencil icon (Edit skill) → Manual	Edits `SKILL.md` only. Use Preview to check rendering, then Save. The `name` in the frontmatter must stay the same. To change files in `references/`, `scripts/`, or `schemas/`, download the skill, edit them, and upload the `.zip` with Replace. Replace resets Available in to Chat only, so re-tick other surfaces.
Download	Download icon (Download)	Saves the skill as a `.zip` you can upload to another workspace.
Delete	Trash icon (Delete skill)	Permanent.

Deleting a skill can’t be undone, and there’s no version history to roll back an edit. Download the .zip before you edit or delete, or turn the switch off instead if you might need the skill again.

Audit Logs record who created, uploaded, edited, re-scoped, or deleted a skill in More → Workspace settings → Skills, but only on Scale, Scale Plus, and Enterprise, and not for skills an agent saves from chat. On other plans nothing records skill changes, so keep every skill’s .zip in a repository and upload changes from there.

Troubleshooting

This skill name is already in use

Another skill in this workspace has that name. Pick a different name, or upload a .zip and choose Replace to overwrite the existing one.

This skill name is reserved

The name matches one of CloudThinker’s built-in skills, such as pdf, docx, or deep-research. Pick a different name.

Failed to create skill

The form lets you submit an empty Description, but the save then fails with this error. Add one sentence saying when to use the skill and click Create again. If the description is filled in, the skill store didn’t accept the file; try again.

Failed to upload skill to executor

This is the literal error text (the executor is the service that stores skill files). Usually the SKILL.md frontmatter is missing, invalid, or lacks a name or description. See skill format troubleshooting.

Only .zip files are accepted

The upload accepts .zip only. Put SKILL.md (and any scripts/, schemas/, or references/ folders) in a folder, zip it, and upload the zip.

No agent can load this skill

This shows as an alert on the skill’s detail panel in More → Workspace settings → Skills. The skill’s SKILL.md frontmatter has no usable description, usually because a manual edit removed or broke the description: line. Edit it by hand, add a description: line, and click Save. Until then the skill doesn’t appear in the / menu.

Cannot preview this skill

The skill’s file content can’t be loaded. Click Recovery with AI to rebuild the SKILL.md with CloudThinker through a short interview, or click Re-upload to restore it from a .zip you kept (for example one you downloaded earlier).

The agent ignores the skill

Check that the switch is on.
Check that the right area is ticked under Available in (for example Review for pull request reviews).
Make the instructions concrete and add examples. Split a long, broad skill into several short ones.

Next steps

Skill format

Structure SKILL.md, set frontmatter, and write rules agents follow.

Knowledge base

Give agents reference docs to look up.

Commands

Run skills and saved prompts from the / menu.

Custom agents

Build an agent for one job and pair it with your skills.

Connections

Customize

Approvals

Workspace settings

Admin Settings

Artifacts and sharing

When to write a skill

Prerequisites

Create a skill

Choose where the skill applies

Test the skill

Edit, download, or delete a skill

Troubleshooting

Next steps

Skill format

Knowledge base

Commands

Custom agents

​When to write a skill

​Prerequisites

​Create a skill

​Choose where the skill applies

​Test the skill

​Edit, download, or delete a skill

​Troubleshooting

​Next steps

Skill format

Knowledge base

Commands

Custom agents

When to write a skill

Prerequisites

Create a skill

Choose where the skill applies

Test the skill

Edit, download, or delete a skill

Troubleshooting

Next steps