refactor(core): skill service stores values, config plugin owns the filesystem

packages/core/src/config/plugin/skill-file.ts

@@ -0,0 +1,57 @@
+export * as SkillFile from "./skill-file"
+
+import path from "path"
+import { Result, Schema, type SchemaIssue, SchemaParser } from "effect"
+import { ConfigMarkdown } from "../markdown"
+import { AbsolutePath } from "../../schema"
+import { Skill } from "../../skill"
+
+const Frontmatter = Schema.Struct({
+  name: Schema.String.pipe(Schema.optional),
+  description: Schema.String.pipe(Schema.optional),
+  slash: Schema.Boolean.pipe(Schema.optional),
+  metadata: Schema.Unknown.pipe(Schema.optional),
+})
+const decodeFrontmatter = SchemaParser.decodeUnknownResult(Frontmatter)
+
+export type ParseResult =
+  | { readonly _tag: "Parsed"; readonly skill: Skill.Info }
+  | { readonly _tag: "Skipped"; readonly reason: "markdown" }
+  | { readonly _tag: "Skipped"; readonly reason: "frontmatter"; readonly issue: SchemaIssue.Issue }
+
+const metadataBoolean = (metadata: unknown, key: string) => {
+  if (metadata === undefined || metadata === null || typeof metadata !== "object" || Array.isArray(metadata)) {
+    return undefined
+  }
+  const value = Reflect.get(metadata, key)
+  if (typeof value === "boolean") return value
+  if (typeof value !== "string") return undefined
+  const normalized = value.trim().toLowerCase()
+  if (normalized === "true") return true
+  if (normalized === "false") return false
+  return undefined
+}
+
+export function parse(directory: string, filepath: string, content: string): ParseResult {
+  const markdown = ConfigMarkdown.parseOption(content)
+  if (!markdown) return { _tag: "Skipped", reason: "markdown" }
+  const decoded = decodeFrontmatter(markdown.data)
+  if (Result.isFailure(decoded)) return { _tag: "Skipped", reason: "frontmatter", issue: decoded.failure }
+  const frontmatter = decoded.success
+  const id =
+    path.dirname(filepath) === directory ? path.basename(filepath, ".md") : path.basename(path.dirname(filepath))
+  const slash = metadataBoolean(frontmatter.metadata, "opencode/slash") ?? frontmatter.slash
+  const autoinvoke = metadataBoolean(frontmatter.metadata, "opencode/autoinvoke")
+  return {
+    _tag: "Parsed",
+    skill: {
+      id: Skill.ID.make(id),
+      name: Skill.Name.make(frontmatter.name ?? id),
+      ...(frontmatter.description === undefined ? {} : { description: frontmatter.description }),
+      ...(slash === undefined ? {} : { slash }),
+      ...(autoinvoke === undefined ? {} : { autoinvoke }),
+      location: AbsolutePath.make(filepath),
+      content: markdown.content,
+    },
+  }
+}

packages/core/src/config/plugin/skill.ts

@@ -1,64 +1,191 @@
 export * as ConfigSkillPlugin from "./skill"
 
 import { define } from "@opencode-ai/plugin/effect/plugin"
+import type { Entry } from "@opencode-ai/schema/config"
+import { FSUtil } from "@opencode-ai/util/fs-util"
+import { Global } from "@opencode-ai/util/global"
 import path from "path"
-import { Effect, Stream } from "effect"
+import { Effect, FiberMap, PubSub, Semaphore, Stream } from "effect"
 import { Config } from "../../config"
+import { Watcher } from "../../filesystem/watcher"
+import { Location } from "../../location"
 import { AbsolutePath } from "../../schema"
 import { Skill } from "../../skill"
-import { Global } from "@opencode-ai/util/global"
-import { Location } from "../../location"
+import { SkillDiscovery } from "../../skill/discovery"
+import { SkillFile } from "./skill-file"
+
+type Source = Skill.DirectorySource | Skill.UrlSource
 
 export const Plugin = define({
   id: "opencode.config.skill",
   effect: Effect.fn(function* (ctx) {
     const config = yield* Config.Service
+    const discovery = yield* SkillDiscovery.Service
+    const fs = yield* FSUtil.Service
     const global = yield* Global.Service
     const location = yield* Location.Service
-    const loaded = { entries: yield* config.entries() }
-    yield* ctx.skill.transform((draft) => {
+    const watcher = yield* Watcher.Service
+    const loaded: { entries: Entry[]; skills: Skill.Info[] } = {
+      entries: yield* config.entries(),
+      skills: [],
+    }
+    const watches = yield* FiberMap.make<string>()
+    const changes = yield* PubSub.sliding<string>(1)
+    const lock = Semaphore.makeUnsafe(1)
+
+    const watch = Effect.fn("ConfigSkillPlugin.watch")(function* (directory: string, type: Watcher.WatchInput["type"]) {
+      const target = path.resolve(directory)
+      const updates = yield* watcher.subscribe({ path: target, type })
+      yield* FiberMap.run(
+        watches,
+        `${type}:${target}`,
+        updates.pipe(Stream.runForEach((update) => PubSub.publish(changes, update.path).pipe(Effect.asVoid))),
+        { onlyIfMissing: true, startImmediately: true },
+      )
+    })
+
+    function firstMissing(target: string): Effect.Effect<string | undefined> {
+      const parent = path.dirname(target)
+      if (parent === target) return Effect.succeed(undefined)
+      return fs.isDir(parent).pipe(Effect.flatMap((exists) => (exists ? Effect.succeed(target) : firstMissing(parent))))
+    }
+
+    const watchDirectory: (directory: string) => Effect.Effect<string[]> = Effect.fn(
+      "ConfigSkillPlugin.watchDirectory",
+    )(function* (directory: string) {
+      const target = path.resolve(directory)
+      const resolved = yield* fs.realPath(directory).pipe(Effect.catch(() => Effect.succeed(undefined)))
+      if (resolved) {
+        yield* watch(resolved, "directory")
+        if (resolved !== target) yield* watch(target, "file")
+        return resolved === target ? [target] : [target, resolved]
+      }
+      const missing = yield* firstMissing(target)
+      if (missing) yield* watch(missing, "file")
+      if (
+        yield* fs.realPath(directory).pipe(
+          Effect.as(true),
+          Effect.catch(() => Effect.succeed(false)),
+        )
+      ) {
+        if (missing) yield* FiberMap.remove(watches, `file:${path.resolve(missing)}`)
+        return yield* watchDirectory(directory)
+      }
+      return [target]
+    })
+
+    const sources = () => {
+      const result: Source[] = []
+      const add = (source: Source) => {
+        if (result.some((item) => Skill.Source.equals(item, source))) return
+        result.push(source)
+      }
       const claude = loaded.entries.flatMap((entry) => (entry.type === "claude" ? [entry.path] : []))
       const agents = loaded.entries.flatMap((entry) => (entry.type === "agents" ? [entry.path] : []))
       const directories = loaded.entries.flatMap((entry) => (entry.type === "directory" ? [entry.path] : []))
       const items = loaded.entries.flatMap((entry) => (entry.type === "document" ? (entry.info.skills ?? []) : []))
       for (const directory of [...claude, ...agents]) {
-        draft.source(
-          Skill.DirectorySource.make({
-            type: "directory",
-            path: AbsolutePath.make(path.join(directory, "skills")),
-          }),
-        )
+        add(Skill.DirectorySource.make({ type: "directory", path: AbsolutePath.make(path.join(directory, "skills")) }))
       }
       for (const directory of directories) {
-        draft.source(
-          Skill.DirectorySource.make({ type: "directory", path: AbsolutePath.make(path.join(directory, "skill")) }),
-        )
-        draft.source(
-          Skill.DirectorySource.make({
-            type: "directory",
-            path: AbsolutePath.make(path.join(directory, "skills")),
-          }),
-        )
+        add(Skill.DirectorySource.make({ type: "directory", path: AbsolutePath.make(path.join(directory, "skill")) }))
+        add(Skill.DirectorySource.make({ type: "directory", path: AbsolutePath.make(path.join(directory, "skills")) }))
       }
       for (const item of items) {
         if (URL.canParse(item) && /^(https?:)$/.test(new URL(item).protocol)) {
-          draft.source(Skill.UrlSource.make({ type: "url", url: item }))
+          add(Skill.UrlSource.make({ type: "url", url: item }))
           continue
         }
         const expanded = item.startsWith("~/") ? path.join(global.home, item.slice(2)) : item
-        draft.source(
+        add(
           Skill.DirectorySource.make({
             type: "directory",
             path: AbsolutePath.make(path.isAbsolute(expanded) ? expanded : path.join(location.directory, expanded)),
           }),
         )
       }
+      return result
+    }
+
+    const load = Effect.fn("ConfigSkillPlugin.load")(function* (source: Source) {
+      const directories =
+        source.type === "directory"
+          ? [source.path]
+          : yield* discovery.pull(source.url).pipe(
+              Effect.catchCause((cause) =>
+                Effect.logWarning("failed to load skill source", {
+                  source: Skill.Source.key(source),
+                  cause,
+                }).pipe(Effect.as([] as AbsolutePath[])),
+              ),
+            )
+      const roots = (yield* Effect.forEach(directories, watchDirectory)).flat()
+      const skills: Skill.Info[] = []
+      for (const directory of directories) {
+        const files = yield* fs
+          .scan("{*.md,**/SKILL.md}", { cwd: directory, absolute: true, include: "file", symlink: true, dot: true })
+          .pipe(Effect.catch(() => Effect.succeed([] as string[])))
+        for (const filepath of files.toSorted()) {
+          const resolved = yield* fs.realPath(filepath).pipe(Effect.catch(() => Effect.succeed(filepath)))
+          if (!roots.some((root) => FSUtil.contains(root, resolved))) yield* watch(path.dirname(resolved), "directory")
+          const content = yield* fs.readFileStringSafe(filepath).pipe(Effect.catch(() => Effect.succeed(undefined)))
+          if (!content) continue
+          const parsed = SkillFile.parse(directory, filepath, content)
+          if (parsed._tag === "Skipped") {
+            yield* Effect.logDebug("skill file skipped", {
+              filepath,
+              reason: parsed.reason,
+              ...(parsed.reason === "frontmatter" ? { issue: parsed.issue } : {}),
+            })
+            continue
+          }
+          skills.push(parsed.skill)
+        }
+      }
+      yield* Effect.logDebug("skill source loaded", {
+        source: Skill.Source.key(source),
+        type: source.type,
+        directories,
+        skills: skills.map((skill) => skill.id),
+      })
+      return skills
+    })
+
+    const refresh = Effect.fn("ConfigSkillPlugin.refresh")(function* (file?: string) {
+      yield* lock.withPermit(
+        Effect.gen(function* () {
+          yield* FiberMap.clear(watches)
+          const skills = new Map<Skill.ID, Skill.Info>()
+          const current = sources()
+          for (const source of current) {
+            for (const skill of yield* load(source)) skills.set(skill.id, skill)
+          }
+          loaded.skills = Array.from(skills.values())
+          if (file) {
+            yield* Effect.logInfo("skills rescanned", {
+              file,
+              sources: current.map(Skill.Source.key),
+              skills: loaded.skills.map((skill) => skill.id),
+            })
+          }
+        }),
+      )
+    })
+
+    yield* Stream.fromPubSub(changes).pipe(
+      Stream.runForEach((file) => refresh(file).pipe(Effect.andThen(ctx.skill.reload()))),
+      Effect.forkScoped({ startImmediately: true }),
+    )
+    yield* refresh()
+    yield* ctx.skill.transform((draft) => {
+      for (const skill of loaded.skills) draft.add(skill)
     })
     yield* ctx.event.subscribe().pipe(
       Stream.filter((event) => event.type === "config.updated"),
       Stream.runForEach(() =>
         config.entries().pipe(
           Effect.tap((entries) => Effect.sync(() => (loaded.entries = entries))),
+          Effect.andThen(refresh()),
           Effect.andThen(ctx.skill.reload()),
         ),
       ),

packages/core/src/plugin/host.ts

@@ -290,8 +290,10 @@ export const make = Effect.fn("PluginHost.make")(function* (plugin: import("../p
       transform: (callback) =>
         skill.transform((draft) => {
           callback({
-            source: (source) => draft.source(Schema.decodeUnknownSync(Skill.Source)(source)),
-            list: draft.list,
+            list: () => mutable(draft.list()),
+            add: (value) => draft.add(Schema.decodeUnknownSync(Skill.Info)(value)),
+            update: draft.update,
+            remove: draft.remove,
           })
         }),
     },

packages/core/src/plugin/internal.ts

@@ -39,6 +39,8 @@ import { Ripgrep } from "../ripgrep"
 import { SessionInstructions } from "../session/instructions"
 import { Shell } from "../shell"
 import { Skill } from "../skill"
+import { SkillDiscovery } from "../skill/discovery"
+import { Watcher } from "../filesystem/watcher"
 import { PatchTool } from "../tool/plugin/patch"
 import { EditTool } from "../tool/plugin/edit"
 import { GlobTool } from "../tool/plugin/glob"
@@ -97,7 +99,9 @@ const services = Effect.fn("PluginInternal.services")(function* () {
   const instructions = yield* SessionInstructions.Service
   const shell = yield* Shell.Service
   const skill = yield* Skill.Service
+  const skillDiscovery = yield* SkillDiscovery.Service
   const tools = yield* Tool.Service
+  const watcher = yield* Watcher.Service
   const wellknown = yield* WellKnown.Service
   return Context.mergeAll(
     Context.make(Agent.Service, agent),
@@ -130,7 +134,9 @@ const services = Effect.fn("PluginInternal.services")(function* () {
     Context.make(SessionInstructions.Service, instructions),
     Context.make(Shell.Service, shell),
     Context.make(Skill.Service, skill),
+    Context.make(SkillDiscovery.Service, skillDiscovery),
     Context.make(Tool.Service, tools),
+    Context.make(Watcher.Service, watcher),
     Context.make(WellKnown.Service, wellknown),
   )
 })
@@ -170,7 +176,9 @@ export const requirements = LayerNode.group([
   SessionInstructions.node,
   Shell.node,
   Skill.node,
+  SkillDiscovery.node,
   Tool.node,
+  Watcher.node,
   WellKnown.node,
 ])
 

packages/core/src/plugin/skill.ts

@@ -28,29 +28,23 @@ export const Plugin = define({
   effect: Effect.fn(function* (ctx) {
     const reportContent = yield* reportContentWithDiagnostics(ctx.app)
     yield* ctx.skill.transform((draft) => {
-      draft.source(
-        Skill.EmbeddedSource.make({
-          type: "embedded",
-          skill: Skill.Info.make({
-            id: Skill.ID.make("opencode"),
-            name: Skill.Name.make("OpenCode"),
-            description: OpencodeDescription,
-            location: AbsolutePath.make("/builtin/opencode.md"),
-            content: OpencodeContent,
-          }),
+      draft.add(
+        Skill.Info.make({
+          id: Skill.ID.make("opencode"),
+          name: Skill.Name.make("OpenCode"),
+          description: OpencodeDescription,
+          location: AbsolutePath.make("/builtin/opencode.md"),
+          content: OpencodeContent,
         }),
       )
-      draft.source(
-        Skill.EmbeddedSource.make({
-          type: "embedded",
-          skill: Skill.Info.make({
-            id: Skill.ID.make("report"),
-            name: Skill.Name.make("Report"),
-            description: REPORT_DESCRIPTION,
-            slash: true,
-            location: AbsolutePath.make("/builtin/report.md"),
-            content: reportContent,
-          }),
+      draft.add(
+        Skill.Info.make({
+          id: Skill.ID.make("report"),
+          name: Skill.Name.make("Report"),
+          description: REPORT_DESCRIPTION,
+          slash: true,
+          location: AbsolutePath.make("/builtin/report.md"),
+          content: reportContent,
         }),
       )
     })