Skills

A skill is a SKILL.md instruction file with optional supporting resources. The prompt lists enabled skill descriptions; the model calls read_skill when it needs the full instructions. Reading a script returns its text—it does not execute it. Configure AgentConfig.SkillClient with pkg/agents/skills. Each agent can have its own global sources while sharing a namespace-scoped user library.

Write a skill

Create skills/release-review/SKILL.md:

---
name: release-review
description: Review a release for missing tests and compatibility changes.
---

Check the changed public APIs, read the relevant tests, and report actionable issues.
Use refs/checklist.md for the release checklist.

Put supporting files beneath the skill folder. Names and descriptions come from frontmatter; uploaded content cannot set its own availability policy.

Attach developer-owned skills

With model configured, import pkg/agents/skills and pkg/agents/prompts:

source, err := skills.NewDirSource("./skills")
if err != nil { return err }
agent, err := hastekit.NewAgent(&hastekit.AgentConfig{
    Name: "reviewer",
    LLM: model,
    SkillClient: skills.NewClient(nil).WithGlobalSkills(source),
    Instruction: hastekit.NewPrompt("Review releases using the relevant skills.",
        prompts.WithResolver(prompts.DefaultResolvers()...)),
})
if err != nil { return err }
_ = agent

Source	Content
`NewDirSource(directory)`	Ordinary skill folders, discovered on each listing
`NewFSSource(fsys)`	An `embed.FS` or another `fs.FS`
`NewBundleSource(bundles...)`	Inline bundles validated and copied at construction
`NewStoreSource(store, namespace)`	An application-managed namespace in a skill store

WithGlobalSkills returns a copy of the client sharing its user store. Globals are always enabled, cannot be disabled by the user, and take precedence over a user skill with the same name. Duplicate names across global sources are a configuration error.

Add a user library

store, err := skills.NewFileStore("./data/skills")
if err != nil { return err }
client := skills.NewClient(store).WithGlobalSkills(source)

Set SkillClient: client on the agent. Its globals are combined with the skills stored under Input.Namespace. The store is shared across agents; the agent name does not create a separate library. An empty namespace passed directly to the client lists globals only. User skills are enabled by default. Disable selected names for one execution with agents.SkillSelection:

result, err := agent.Run(ctx, &hastekit.Input{
    Namespace: "tenant-123",
    ThreadID: "release-42",
    Skills: agents.SkillSelection{Disable: []string{"writing-style"}},
    Message: hastekit.UserTurn("Review this release."),
})
if err != nil { return err }
_ = result

There is no Enable list. Unknown disabled names are ignored, and global skills remain enabled. Send the selection on each new turn and approval resume; handoffs and background continuations inherit the originating run’s selection. Disabling a skill does not remove instructions already read into history.

Read and extend the catalog

Use agent.ListSkills(ctx, namespace, runContext, selection) for a picker with Global and Enabled flags. The agent refreshes its catalog when entering a run, fixes the enabled names and resource allowlist for that execution, and resolves content when it is read. A listing error fails the run. Use versioned custom storage if reads must remain pinned to one content version. The read_skill tool accepts the exact skill name and an optional file. An omitted file returns instructions without frontmatter; file: "SKILL.md" returns the original file. Other reads are limited to the listed resources. Implement skills.Source for a custom global source (List, Read), or implement the consumer-owned agents.SkillClient:

type SkillClient interface {
    ListSkills(context.Context, string, map[string]any) ([]agents.Skill, error)
    ReadSkill(context.Context, string, map[string]any, string, string) (string, error)
}

Arguments after context are namespace, run context, then skill name and file for reads. Namespace is authoritative; RunContext["Namespace"] has no special meaning. Clients must support concurrent calls. Temporal and Restate perform listing and reading inside activities or durable steps. See Skill storage and management for uploads, S3, management routes, and caching.

Getting started

Core concepts

Models and providers

Tools and capabilities

Multi-agent patterns

Interfaces

Durable execution

Scheduled work

Workflows

Testing and operations

Write a skill

Attach developer-owned skills

Add a user library

Read and extend the catalog

​Write a skill

​Attach developer-owned skills

​Add a user library

​Read and extend the catalog

Write a skill

Attach developer-owned skills

Add a user library

Read and extend the catalog