Adapt workspace context to session prefixes

packages/prompt/workspace-context/README.md

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+# @deepseek-ai/dsh-workspace-context
+
+Per-session workspace instruction loading for `AGENTS.md`-compatible files. The plugin freezes the initial user-global and project instruction chain into the request prefix, then discovers nested files and reports later changes or removals through durable context messages after successful filesystem tool calls.
+
+## Lifecycle
+
+The baseline is composed once per agent-loop instance on `agent/session-prefix`. It reads `$DSH_HOME/AGENTS.md` followed by one configured instruction candidate in each directory from the project root to `agent.session.header.cwd`. The prefix is placed before all derived history, recorded in `EpochHeader.messagePrefix`, and reused verbatim for that loop instance. Because the plugin prepends its contribution before delegating, a later-registered skills catalog appears after workspace instructions.
+
+The plugin also listens on `tools/post-execute` for successful first-party `read`, `write`, and `edit` calls. Each touch checks newly reached descendant scopes and every previously loaded scope. A new file is attached as `additionalContext`; a changed file or candidate switch appends a replacement; a missing final candidate appends a removal notice. This follows structured filesystem activity rather than shell `cd`, because each local bash call starts a fresh shell and parsing arbitrary shell syntax would be unreliable.
+
+Instruction reads use the optional `ctx.fs` provider. The plugin does not statically inject `fs`, so providerless product trees still boot and instruction loading becomes a no-op until a provider is present. It calls `ctx.fs.lstat` before resolving a candidate, rejecting a final-component symlink instead of following repository-owned links across the trust boundary. A provider failure after a file was loaded is treated as temporarily unavailable, not as proof that the file was deleted.
+
+## Prompt Shape
+
+Baseline instructions are request-only user-role prefix messages framed with the familiar system-reminder pattern:
+
+```md
+<system-reminder>
+The following workspace instructions may be relevant to your work. Use them as guidance when applicable. More specific instructions take precedence over broader ones. They do not override system, developer, or direct user instructions.
+
+Instructions from: ~/.dsh/AGENTS.md
+
+...
+
+Instructions from: AGENTS.md
+
+...
+</system-reminder>
+```
+
+Newly reached scopes use a durable raw `context/message`:
+
+```md
+<system-reminder>
+Additional instructions from: packages/app/AGENTS.md
+
+These instructions apply to work under `packages/app`. Use them as guidance when relevant; more specific instructions take precedence. They do not override system, developer, or direct user instructions.
+
+...
+</system-reminder>
+```
+
+A same-file edit starts with `Updated instructions from: <path>` and says to use the new content instead of the previously loaded content. A candidate switch additionally names the old path. When no candidate remains, the message is `Instructions removed: <path>` followed by `The previously loaded instructions from this file no longer apply.` Literal `</system-reminder>` text inside an instruction file is escaped so file content cannot close the plugin-owned frame.
+
+The core `context/message` envelope is disabled for these messages because the plugin already owns the complete `<system-reminder>` framing. This is caller-selected with `envelope: 'raw'`; ordinary injected context still receives the canonical `<context source="...">` envelope.
+
+## State And Refresh
+
+Model-visible text contains no hidden state markers. Each dynamic context event instead carries JSON metadata with a versioned list of `{ action, scope, path, previousPath?, digest? }` changes. On every relevant tool touch, the plugin reconstructs loaded state from its visible session events and overlays a short in-memory pending window for context returned by `tools/post-execute` but not yet appended by the loop.
+
+An unchanged path and SHA-256 content digest is not injected again. Resume works because visible metadata is persisted in the session log. Compaction re-arms a scope after its context event leaves the visible surface. A removal is a tombstone, so a later candidate reappearance is loaded again. Only changes actually rendered within the byte budget enter metadata and pending state; an omitted change remains eligible for a later touch.
+
+The frozen baseline itself is not rewritten mid-instance. Its initial path/digest map is retained as comparison state; the next successful filesystem touch appends any baseline replacement or removal. A resumed loop recomposes the current baseline and also reconciles still-visible dynamic scopes during prefix composition. There is no file watcher, so an on-disk change becomes visible at the next successful `read`, `write`, or `edit` touch, or when a resumed loop composes its prefix.
+
+## Configuration
+
+```ts
+export interface Config {
+  dshHome?: string
+  projectRootMarkers?: string[]
+  maxBytes?: number
+  instructionFileCandidates?: string[]
+}
+```
+
+`projectRootMarkers` defaults to `['.git']`, `maxBytes` to `65536`, and `instructionFileCandidates` to `['AGENTS.md', 'CLAUDE.md']`. In each project directory, the first existing candidate wins; with defaults, `AGENTS.md` is native and `CLAUDE.md` is the compatibility fallback. Candidate entries must be same-directory file names, so empty entries, `.`/`..`, and entries containing `/` or `\` are ignored.
+
+The user-global file is always `$DSH_HOME/AGENTS.md`; the candidate list only controls project scopes. `$DSH_HOME` defaults to `~/.dsh`, and configured `~`, `~/...`, and Windows-style `~\...` prefixes are expanded against the operating-system home directory. A non-positive or non-finite byte budget disables both baseline and dynamic loading.
+
+## Budgeting And Cache
+
+Rendering preserves the most specific instruction files first. It drops whole broader files before truncating the most-specific file and emits a visible `Workspace instruction budget ...` notice naming omitted and truncated paths. The rendered bytes never exceed `maxBytes`.
+
+File text is cached by normalized absolute path plus the provider's opaque version and optional size. A signature change causes a re-read. Discovery carries the signature into reading so a cache hit does not stat the same file twice in one pass. Cache identity is separate from loaded-state identity: persisted structured metadata, not cached prose, controls duplicate suppression.
+
+## Non-goals
+
+This implementation does not parse shell commands, recursively scan the repository, load lowercase names by default, interpret `.claude/rules/` or `@path` imports, watch files continuously, or summarize instruction content with a model. Same-directory names such as `CLAUDE.local.md` can be opted into through `instructionFileCandidates`; rule directories and import semantics need separate designs.

packages/prompt/workspace-context/package.json

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+{
+  "name": "@deepseek-ai/dsh-workspace-context",
+  "description": "Workspace context loader for AGENTS.md/CLAUDE.md instruction files",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-agent": "^0.0.1",
+    "@deepseek-ai/dsh-fs": "^0.0.1",
+    "@deepseek-ai/dsh-llm": "^0.0.1",
+    "@deepseek-ai/dsh-paths": "^0.0.1",
+    "@deepseek-ai/dsh-session": "^0.0.1",
+    "@deepseek-ai/dsh-tools": "^0.0.1",
+    "cordis": "^4.0.0-rc.6"
+  },
+  "dependencies": {
+    "schemastery": "^3.18.0"
+  },
+  "devDependencies": {
+    "@cordisjs/plugin-loader": "workspace:^",
+    "@deepseek-ai/dsh-agent": "workspace:^",
+    "@deepseek-ai/dsh-agent-loop": "workspace:^",
+    "@deepseek-ai/dsh-fs": "workspace:^",
+    "@deepseek-ai/dsh-fs-local": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-llm-deepseek": "workspace:^",
+    "@deepseek-ai/dsh-paths": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-system-prompt": "workspace:^",
+    "@deepseek-ai/dsh-tool-fs": "workspace:^",
+    "@deepseek-ai/dsh-tools": "workspace:^",
+    "cordis": "^4.0.0-rc.6"
+  }
+}

packages/prompt/workspace-context/src/config.ts

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+import z from 'schemastery'
+import { resolveDshHome } from '@deepseek-ai/dsh-paths'
+
+const DEFAULT_MAX_BYTES = 64 * 1024
+const DEFAULT_PROJECT_ROOT_MARKERS = ['.git'] as const
+const DEFAULT_INSTRUCTION_FILE_CANDIDATES = ['AGENTS.md', 'CLAUDE.md'] as const
+const RESERVED_PATH_SEGMENTS = new Set(['', '.', '..'])
+
+/** User-facing workspace instruction loader configuration. */
+export interface Config {
+  /** Harness home containing the fixed user-global `AGENTS.md`; defaults to `$DSH_HOME` or `~/.dsh`. */
+  dshHome?: string
+  /** Directory entries that identify the project root while walking upward from the session cwd. */
+  projectRootMarkers?: string[]
+  /** Maximum UTF-8 bytes in one rendered baseline or dynamic instruction batch; non-positive disables loading. */
+  maxBytes?: number
+  /** Ordered same-directory project candidates; the first existing regular file wins in each scope. */
+  instructionFileCandidates?: string[]
+}
+
+export const Config: z<Config> = z.object({
+  dshHome: z.string(),
+  projectRootMarkers: z.array(z.string()).default([...DEFAULT_PROJECT_ROOT_MARKERS]),
+  maxBytes: z.number().default(DEFAULT_MAX_BYTES),
+  instructionFileCandidates: z.array(z.string()).default([...DEFAULT_INSTRUCTION_FILE_CANDIDATES]),
+})
+
+/** Fully defaulted configuration used by discovery and reconciliation. */
+export interface ResolvedConfig {
+  dshHome: string
+  projectRootMarkers: string[]
+  maxBytes: number
+  instructionFileCandidates: string[]
+}
+
+/**
+ * Resolve defaults, the harness home, and valid same-directory candidates.
+ * @param config - user-facing plugin configuration.
+ * @returns normalized runtime configuration.
+ */
+export function resolveConfig(config: Config): ResolvedConfig {
+  return {
+    dshHome: resolveDshHome(config.dshHome),
+    projectRootMarkers: config.projectRootMarkers ?? [...DEFAULT_PROJECT_ROOT_MARKERS],
+    maxBytes: config.maxBytes ?? DEFAULT_MAX_BYTES,
+    instructionFileCandidates: resolveInstructionFileCandidates(config.instructionFileCandidates),
+  }
+}
+
+function resolveInstructionFileCandidates(candidates: string[] | undefined): string[] {
+  return (candidates ?? [...DEFAULT_INSTRUCTION_FILE_CANDIDATES]).filter(candidate => (
+    !RESERVED_PATH_SEGMENTS.has(candidate) && !/[\\/]/.test(candidate)
+  ))
+}

packages/prompt/workspace-context/src/files.ts

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+import { lstat, readFile, stat } from 'node:fs/promises'
+import { dirname, isAbsolute, join, relative, resolve } from 'node:path'
+import type { FileSystem, FsInfo, FsPathInfo, FsTarget } from '@deepseek-ai/dsh-fs'
+import { DEFAULT_DSH_HOME_DISPLAY, defaultDshHome } from '@deepseek-ai/dsh-paths'
+import { resolveConfig, type ResolvedConfig } from './config.ts'
+import { renderWorkspaceContext, type RenderedWorkspaceContext } from './render.ts'
+
+/** An instruction candidate identified by absolute and model-facing paths. */
+export interface InstructionFile {
+  absolutePath: string
+  displayPath: string
+}
+
+/** An instruction file whose UTF-8 content was read successfully. */
+export interface LoadedInstructionFile extends InstructionFile {
+  content: string
+}
+
+interface FileSignature {
+  version: string
+  size: number | undefined
+}
+
+interface CachedContent extends FileSignature {
+  content: string
+}
+
+interface DiscoveredInstructionFile extends InstructionFile {
+  signature: FileSignature
+  target?: FsTarget
+}
+
+/** Provider-signature-keyed content cache shared across plugin hooks. */
+export type InstructionContentCache = Map<string, CachedContent>
+
+interface DiscoverOptions {
+  cwd: string
+  dshHome?: string
+  projectRootMarkers?: string[]
+  instructionFileCandidates?: string[]
+}
+
+interface LoadOptions extends DiscoverOptions {
+  maxBytes?: number
+  cache?: InstructionContentCache
+}
+
+/** Rendered baseline plus the files that survived byte budgeting. */
+export interface RenderedInstructionSet {
+  rendered: RenderedWorkspaceContext
+  included: LoadedInstructionFile[]
+}
+
+/** Tri-state scope probe that distinguishes confirmed absence from provider failure. */
+export type ScopeInstructionProbe =
+  | { kind: 'present'; file: LoadedInstructionFile }
+  | { kind: 'absent' }
+  | { kind: 'unavailable' }
+
+async function nodeStatFile(path: string): Promise<FileSignature | undefined> {
+  try {
+    const info = await lstat(path)
+    if (!info.isFile()) return undefined
+    return { version: `${info.mtimeMs}:${info.size}`, size: info.size }
+  } catch {
+    // Candidates can disappear while discovery is in progress.
+    return undefined
+  }
+}
+
+async function fsStatFile(
+  path: string,
+  fileSystem: FileSystem,
+): Promise<DiscoveredInstructionFile['signature'] & { target: FsTarget } | undefined> {
+  try {
+    const pathInfo = await fileSystem.lstat(path)
+    if (pathInfo?.type !== 'file') return undefined
+    const target = await fileSystem.resolve(path)
+    const info = await fileSystem.stat(target)
+    if (info?.type !== 'file') return undefined
+    return { version: info.version, size: info.size, target }
+  } catch {
+    // Provider absence and discovery races are both non-fatal.
+    return undefined
+  }
+}
+
+async function statFile(
+  path: string,
+  fileSystem?: FileSystem,
+): Promise<(DiscoveredInstructionFile['signature'] & { target?: FsTarget }) | undefined> {
+  return fileSystem === undefined ? nodeStatFile(path) : fsStatFile(path, fileSystem)
+}
+
+async function existsAsMarker(path: string, fileSystem?: FileSystem): Promise<boolean> {
+  if (fileSystem !== undefined) {
+    try {
+      const target = await fileSystem.resolve(path)
+      return await fileSystem.stat(target) !== undefined
+    } catch {
+      return false
+    }
+  }
+  try {
+    await stat(path)
+    return true
+  } catch {
+    return false
+  }
+}
+
+/**
+ * Walk upward to the first directory containing a configured root marker.
+ * @param cwd - absolute session working directory where the walk begins.
+ * @param markers - child names that identify a project root.
+ * @param fileSystem - optional provider used instead of host filesystem probes.
+ * @returns the discovered project root, or `cwd` when no marker exists.
+ */
+export async function findProjectRoot(
+  cwd: string,
+  markers: readonly string[],
+  fileSystem?: FileSystem,
+): Promise<string> {
+  let current = resolve(cwd)
+  for (;;) {
+    for (const marker of markers) {
+      if (await existsAsMarker(join(current, marker), fileSystem)) return current
+    }
+    const parent = dirname(current)
+    if (parent === current) return resolve(cwd)
+    current = parent
+  }
+}
+
+/**
+ * Build the inclusive root-to-cwd directory chain.
+ * @param root - root directory expected to contain or equal `cwd`.
+ * @param cwd - most-specific directory in the chain.
+ * @returns directories ordered from broadest to most specific.
+ */
+export function ancestorChain(root: string, cwd: string): string[] {
+  const chain: string[] = []
+  let current = resolve(cwd)
+  const resolvedRoot = resolve(root)
+  while (current !== resolvedRoot) {
+    chain.push(current)
+    const parent = dirname(current)
+    /* v8 ignore next -- discovery always supplies cwd or an ancestor root. */
+    if (parent === current) break
+    current = parent
+  }
+  chain.push(resolvedRoot)
+  return chain.reverse()
+}
+
+/**
+ * Find descendant directories crossed between a cwd and a touched file.
+ * @param root - session cwd that bounds nested discovery.
+ * @param touchedPath - absolute path or path relative to `root`.
+ * @returns descendant directories from shallowest through the touched file's parent.
+ */
+export function descendantDirsBetween(root: string, touchedPath: string): string[] {
+  const resolvedRoot = resolve(root)
+  const targetPath = isAbsolute(touchedPath) ? resolve(touchedPath) : resolve(resolvedRoot, touchedPath)
+  const targetDir = dirname(targetPath)
+  const rel = relative(resolvedRoot, targetDir)
+  if (rel.length === 0 || rel.startsWith('..') || isAbsolute(rel)) return []
+  return ancestorChain(resolvedRoot, targetDir).slice(1)
+}
+
+/**
+ * Convert an absolute instruction path to its project-root-relative display form.
+ * @param root - project root used as the display base.
+ * @param path - absolute path to display.
+ * @returns the root-relative path.
+ */
+export function relativeDisplay(root: string, path: string): string {
+  return relative(root, path)
+}
+
+async function firstExistingInstructionFile(
+  dir: string,
+  root: string,
+  instructionFileCandidates: readonly string[],
+  fileSystem?: FileSystem,
+): Promise<DiscoveredInstructionFile | undefined> {
+  for (const candidate of instructionFileCandidates) {
+    const path = join(dir, candidate)
+    const fileSignature = await statFile(path, fileSystem)
+    if (fileSignature !== undefined) {
+      const { target, ...signature } = fileSignature
+      return {
+        absolutePath: path,
+        displayPath: relativeDisplay(root, path),
+        signature,
+        ...target === undefined ? {} : { target },
+      }
+    }
+  }
+  return undefined
+}
+
+async function discoverInstructionFiles(
+  options: DiscoverOptions,
+  fileSystem?: FileSystem,
+): Promise<DiscoveredInstructionFile[]> {
+  const config = resolveConfig(options)
+  const files: DiscoveredInstructionFile[] = []
+  const seen = new Set<string>()
+  const addFile = (file: DiscoveredInstructionFile): void => {
+    if (seen.has(file.absolutePath)) return
+    seen.add(file.absolutePath)
+    files.push(file)
+  }
+
+  const userGlobal = join(config.dshHome, 'AGENTS.md')
+  const userGlobalSignature = await statFile(userGlobal, fileSystem)
+  if (userGlobalSignature !== undefined) {
+    const { target, ...signature } = userGlobalSignature
+    addFile({
+      absolutePath: userGlobal,
+      displayPath: userGlobalDisplayPath(config.dshHome),
+      signature,
+      ...target === undefined ? {} : { target },
+    })
+  }
+
+  const cwd = resolve(options.cwd)
+  const projectRoot = await findProjectRoot(cwd, config.projectRootMarkers, fileSystem)
+  for (const dir of ancestorChain(projectRoot, cwd)) {
+    const file = await firstExistingInstructionFile(dir, projectRoot, config.instructionFileCandidates, fileSystem)
+    if (file !== undefined) addFile(file)
+  }
+  return files
+}
+
+/**
+ * Discover host-visible user-global and root-to-cwd instruction candidates.
+ * @param options - cwd, home, root marker, and candidate configuration.
+ * @returns de-duplicated instruction paths in model precedence order.
+ */
+export async function discoverBaselineInstructionFiles(options: DiscoverOptions): Promise<InstructionFile[]> {
+  return (await discoverInstructionFiles(options)).map(({ absolutePath, displayPath }) => ({ absolutePath, displayPath }))
+}
+
+async function readCached(
+  file: DiscoveredInstructionFile,
+  cache: InstructionContentCache,
+  fileSystem?: FileSystem,
+): Promise<string | undefined> {
+  const path = file.absolutePath
+  const { signature } = file
+  const cached = cache.get(path)
+  if (cached !== undefined && cached.version === signature.version && cached.size === signature.size) {
+    return cached.content
+  }
+  try {
+    const content = fileSystem === undefined || file.target === undefined
+      ? await readFile(path, 'utf8')
+      : await fileSystem.readText(file.target)
+    cache.set(path, { ...signature, content })
+    return content
+  } catch {
+    // A file may disappear or become unreadable after its metadata probe.
+    return undefined
+  }
+}
+
+/**
+ * Discover, read, and render the baseline instruction chain.
+ * @param options - discovery, byte-budget, and optional cache configuration.
+ * @param fileSystem - optional provider used instead of host filesystem reads.
+ * @returns rendered baseline context, or undefined when nothing can be loaded.
+ */
+export async function loadBaselineInstructions(
+  options: LoadOptions,
+  fileSystem?: FileSystem,
+): Promise<RenderedWorkspaceContext | undefined> {
+  return (await loadBaselineInstructionSet(options, fileSystem))?.rendered
+}
+
+/**
+ * Load a baseline together with the files retained after rendering.
+ * @param options - discovery, byte-budget, and optional cache configuration.
+ * @param fileSystem - optional provider used instead of host filesystem reads.
+ * @returns rendered context and retained files, or undefined when empty or disabled.
+ */
+export async function loadBaselineInstructionSet(
+  options: LoadOptions,
+  fileSystem?: FileSystem,
+): Promise<RenderedInstructionSet | undefined> {
+  const config = resolveConfig(options)
+  if (config.maxBytes <= 0 || !Number.isFinite(config.maxBytes)) return undefined
+  const cache = options.cache ?? new Map<string, CachedContent>()
+  const discovered = await discoverInstructionFiles(options, fileSystem)
+  const loaded: LoadedInstructionFile[] = []
+  for (const file of discovered) {
+    const content = await readCached(file, cache, fileSystem)
+    if (content !== undefined) loaded.push({ absolutePath: file.absolutePath, displayPath: file.displayPath, content })
+  }
+  if (loaded.length === 0) return undefined
+  const rendered = renderWorkspaceContext(loaded, { maxBytes: config.maxBytes })
+  const omitted = new Set(rendered.omitted.map(file => file.absolutePath))
+  return { rendered, included: loaded.filter(file => !omitted.has(file.absolutePath)) }
+}
+
+/**
+ * Probe the current first-winning instruction candidate for one logical scope.
+ * @param scope - `user-global`, `.`, or a project-relative directory.
+ * @param projectRoot - project root used to resolve and display project scopes.
+ * @param resolved - normalized plugin configuration.
+ * @param cache - shared content cache.
+ * @param fileSystem - provider used for no-follow probing and reading.
+ * @returns present content, confirmed absence, or temporary unavailability.
+ */
+export async function loadScopeInstruction(
+  scope: string,
+  projectRoot: string,
+  resolved: ResolvedConfig,
+  cache: InstructionContentCache,
+  fileSystem: FileSystem,
+): Promise<ScopeInstructionProbe> {
+  const dir = scope === 'user-global'
+    ? resolved.dshHome
+    : scope === '.' ? projectRoot : join(projectRoot, scope)
+  const candidates = scope === 'user-global' ? ['AGENTS.md'] : resolved.instructionFileCandidates
+  for (const candidate of candidates) {
+    const absolutePath = join(dir, candidate)
+    let pathInfo: FsPathInfo | undefined
+    try {
+      pathInfo = await fileSystem.lstat(absolutePath)
+    } catch {
+      return { kind: 'unavailable' }
+    }
+    if (pathInfo === undefined || pathInfo.type !== 'file') continue
+    let target: FsTarget
+    let info: FsInfo | undefined
+    try {
+      target = await fileSystem.resolve(absolutePath)
+      info = await fileSystem.stat(target)
+    } catch {
+      return { kind: 'unavailable' }
+    }
+    if (info?.type !== 'file') return { kind: 'unavailable' }
+    const discovered: DiscoveredInstructionFile = {
+      absolutePath,
+      displayPath: scope === 'user-global' ? userGlobalDisplayPath(resolved.dshHome) : relativeDisplay(projectRoot, absolutePath),
+      signature: { version: info.version, size: info.size },
+      target,
+    }
+    const content = await readCached(discovered, cache, fileSystem)
+    if (content === undefined) return { kind: 'unavailable' }
+    return { kind: 'present', file: { absolutePath, displayPath: discovered.displayPath, content } }
+  }
+  return { kind: 'absent' }
+}
+
+function userGlobalDisplayPath(dshHome: string): string {
+  return dshHome === resolve(defaultDshHome()) ? `${DEFAULT_DSH_HOME_DISPLAY}/AGENTS.md` : '$DSH_HOME/AGENTS.md'
+}

packages/prompt/workspace-context/src/index.ts

@@ -0,0 +1,117 @@
+/**
+ * Workspace instruction loader for AGENTS.md-compatible files.
+ *
+ * Baseline instructions are frozen into `agent/session-prefix`; successful fs
+ * tool touches reconcile nested, changed, and removed instructions through
+ * `tools/post-execute` for the next model request. Plugin lifecycle reads use
+ * the optional `ctx.fs` provider, so providerless products mount it as a no-op.
+ *
+ * @module @deepseek-ai/dsh-workspace-context
+ */
+
+import type { Context } from 'cordis'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import type { Message } from '@deepseek-ai/dsh-llm'
+import type { PostToolDecision, ToolExecution, ToolExecutionResult } from '@deepseek-ai/dsh-tools'
+import { Config, resolveConfig, type ResolvedConfig } from './config.ts'
+import {
+  loadBaselineInstructionSet,
+  type InstructionContentCache,
+} from './files.ts'
+import {
+  baselineInstructionChanges,
+  concatContext,
+  dynamicInstructionContext,
+  name,
+  reconcileInstructionContext,
+  workspaceContextMessage,
+  type PendingInstructionChange,
+} from './state.ts'
+import type { WorkspaceInstructionChange } from './render.ts'
+
+export { Config, name }
+export {
+  discoverBaselineInstructionFiles,
+  loadBaselineInstructions,
+} from './files.ts'
+export type {
+  InstructionContentCache,
+  InstructionFile,
+  LoadedInstructionFile,
+} from './files.ts'
+export { renderWorkspaceContext } from './render.ts'
+export type { RenderedWorkspaceContext, TruncatedInstruction } from './render.ts'
+
+export function apply(ctx: Context, config: Config): void {
+  const resolved: ResolvedConfig = resolveConfig(config)
+  const cache: InstructionContentCache = new Map()
+  const pendingNestedChanges = new WeakMap<object, Map<string, PendingInstructionChange>>()
+  const baselineInstructionStates = new WeakMap<object, Map<string, WorkspaceInstructionChange>>()
+
+  ctx.on('agent/session-prefix', async (agent: Agent, _prefix, _signal, next): Promise<Message[]> => {
+    const rest = await next()
+    if (resolved.maxBytes <= 0 || !Number.isFinite(resolved.maxBytes)) return rest
+    const fileSystem = ctx.get('fs')
+    if (fileSystem === undefined) return rest
+    /* v8 ignore next -- normal agents carry an absolute session cwd. */
+    const cwd = agent.session.header.cwd ?? process.cwd()
+    const instructions = await loadBaselineInstructionSet({
+      cwd,
+      dshHome: resolved.dshHome,
+      projectRootMarkers: resolved.projectRootMarkers,
+      maxBytes: resolved.maxBytes,
+      instructionFileCandidates: resolved.instructionFileCandidates,
+      cache,
+    }, fileSystem)
+    baselineInstructionStates.set(agent.session, baselineInstructionChanges(instructions?.included ?? []))
+
+    const update = await reconcileInstructionContext(
+      agent,
+      resolved,
+      cache,
+      pendingNestedChanges,
+      baselineInstructionStates,
+      fileSystem,
+      { includeBaselineScopes: false },
+    )
+    if (update !== undefined) {
+      agent.inject(update.content, {
+        source: update.source,
+        envelope: update.envelope,
+        meta: update.meta,
+      })
+    }
+    if (instructions === undefined || instructions.rendered.text.length === 0) return rest
+    return [workspaceContextMessage(instructions.rendered.text), ...rest]
+  })
+
+  ctx.on('tools/post-execute', async (
+    exec: ToolExecution,
+    result: ToolExecutionResult,
+    next,
+  ): Promise<PostToolDecision> => {
+    const downstream = await next()
+    const fileSystem = ctx.get('fs')
+    if (fileSystem === undefined) return downstream
+    const context = await dynamicInstructionContext(
+      exec.agent,
+      exec,
+      result,
+      resolved,
+      cache,
+      pendingNestedChanges,
+      baselineInstructionStates,
+      fileSystem,
+    )
+    if (context === undefined) return downstream
+    const additionalContext = concatContext(context, downstream.additionalContext)
+    if (downstream.kind === 'block') {
+      return { kind: 'block', feedback: downstream.feedback, additionalContext }
+    }
+    return {
+      kind: 'accept',
+      ...downstream.content !== undefined ? { content: downstream.content } : {},
+      additionalContext,
+    }
+  })
+}

packages/prompt/workspace-context/src/render.ts

@@ -0,0 +1,243 @@
+import { dirname } from 'node:path'
+import type { InstructionFile, LoadedInstructionFile } from './files.ts'
+
+const SYSTEM_REMINDER_OPEN = '<system-reminder>'
+const SYSTEM_REMINDER_CLOSE = '</system-reminder>'
+const WORKSPACE_CONTEXT_INTRO = 'The following workspace instructions may be relevant to your work. '
+  + 'Use them as guidance when applicable. More specific instructions take precedence over broader ones. '
+  + 'They do not override system, developer, or direct user instructions.'
+const COMPACT_WORKSPACE_CONTEXT_INTRO = 'Workspace instructions were omitted or truncated to fit the configured byte budget.'
+
+/** Byte-accounting record for one truncated instruction file. */
+export interface TruncatedInstruction {
+  displayPath: string
+  originalBytes: number
+  includedBytes: number
+}
+
+/** Bounded model-facing text plus omitted and truncated source records. */
+export interface RenderedWorkspaceContext {
+  text: string
+  omitted: InstructionFile[]
+  truncated: TruncatedInstruction[]
+}
+
+/** Structured dynamic state persisted outside model-visible prompt prose. */
+export interface WorkspaceInstructionChange {
+  action: 'set' | 'replace' | 'remove'
+  scope: string
+  path: string
+  previousPath?: string
+  digest?: string
+}
+
+/** One state transition paired with the content used to render it. */
+export interface ChangeRenderItem {
+  change: WorkspaceInstructionChange
+  file: LoadedInstructionFile
+}
+
+interface RenderStyle {
+  intro: string
+  section(file: LoadedInstructionFile): string
+}
+
+function byteLength(value: string): number {
+  return Buffer.byteLength(value, 'utf8')
+}
+
+function truncateUtf8(value: string, maxBytes: number): string {
+  let truncated = Buffer.from(value, 'utf8').subarray(0, Math.max(0, maxBytes)).toString('utf8')
+  while (byteLength(truncated) > maxBytes) {
+    truncated = truncated.slice(0, -1)
+  }
+  return truncated
+}
+
+function escapeInstructionContent(content: string): string {
+  return content.replaceAll(SYSTEM_REMINDER_CLOSE, '<\\/system-reminder>')
+}
+
+function sectionText(file: LoadedInstructionFile): string {
+  return `Instructions from: ${file.displayPath}\n\n${escapeInstructionContent(file.content)}`
+}
+
+/**
+ * Derive the logical instruction scope from a model-facing path.
+ * @param displayPath - project-relative or user-global instruction path.
+ * @returns `user-global`, `.`, or the containing project-relative directory.
+ */
+export function scopeForDisplayPath(displayPath: string): string {
+  if (displayPath === '~/.dsh/AGENTS.md' || displayPath === '$DSH_HOME/AGENTS.md') return 'user-global'
+  return dirname(displayPath)
+}
+
+function additionalSectionText(file: LoadedInstructionFile): string {
+  const scope = scopeForDisplayPath(file.displayPath)
+  return [
+    `Additional instructions from: ${file.displayPath}`,
+    '',
+    `These instructions apply to work under \`${scope}\`. Use them as guidance when relevant; more specific instructions take precedence. They do not override system, developer, or direct user instructions.`,
+    '',
+    escapeInstructionContent(file.content),
+  ].join('\n')
+}
+
+const BASELINE_RENDER_STYLE: RenderStyle = { intro: WORKSPACE_CONTEXT_INTRO, section: sectionText }
+
+function changedSectionText(item: ChangeRenderItem): string {
+  const { change, file } = item
+  if (change.action === 'set') return additionalSectionText(file)
+  if (change.action === 'remove') {
+    return `Instructions removed: ${change.path}\n\nThe previously loaded instructions from this file no longer apply.`
+  }
+  const description = change.previousPath === undefined
+    ? 'This file changed after it was loaded. Use the following content instead of the previously loaded instructions from this file.'
+    : `The instructions previously loaded from \`${change.previousPath}\` no longer apply. Use the following content for \`${change.scope}\` instead.`
+  return [
+    `Updated instructions from: ${change.path}`,
+    '',
+    description,
+    '',
+    escapeInstructionContent(file.content),
+  ].join('\n')
+}
+
+/**
+ * Render one reconciliation batch and retain only transitions that fit.
+ * @param items - ordered state transitions and current file contents.
+ * @param maxBytes - maximum UTF-8 bytes allowed in the rendered batch.
+ * @returns bounded prompt text and the transitions actually represented by it.
+ */
+export function renderInstructionChanges(
+  items: ChangeRenderItem[],
+  maxBytes: number,
+): { text: string; changes: WorkspaceInstructionChange[] } {
+  const byAbsolutePath = new Map(items.map(item => [item.file.absolutePath, item]))
+  const style: RenderStyle = {
+    intro: '',
+    section(file) {
+      const item = byAbsolutePath.get(file.absolutePath)
+      /* v8 ignore next -- the renderer receives exactly the files used to construct this map. */
+      return item === undefined ? '' : changedSectionText({ ...item, file })
+    },
+  }
+  const rendered = renderInstructionContext(items.map(item => item.file), maxBytes, style)
+  const omitted = new Set(rendered.omitted.map(file => file.absolutePath))
+  return {
+    text: rendered.text,
+    changes: items.filter(item => !omitted.has(item.file.absolutePath)).map(item => item.change),
+  }
+}
+
+function markerText(maxBytes: number, omitted: InstructionFile[], truncated: TruncatedInstruction[]): string {
+  if (omitted.length === 0 && truncated.length === 0) return ''
+  const parts: string[] = []
+  if (omitted.length > 0) {
+    parts.push(`omitted ${omitted.map(file => file.displayPath).join(', ')}`)
+  }
+  if (truncated.length > 0) {
+    parts.push(`truncated ${truncated.map(item => `${item.displayPath} from ${item.originalBytes} to ${item.includedBytes} bytes`).join(', ')}`)
+  }
+  return `Workspace instruction budget ${maxBytes} bytes: ${parts.join('; ')}`
+}
+
+function buildInstructionText(
+  files: LoadedInstructionFile[],
+  maxBytes: number,
+  omitted: InstructionFile[],
+  truncated: TruncatedInstruction[],
+  style: RenderStyle,
+): string {
+  const marker = markerText(maxBytes, omitted, truncated)
+  const body = [marker, style.intro, ...files.map(file => style.section(file))].filter(block => block.length > 0)
+  return [SYSTEM_REMINDER_OPEN, body.join('\n\n'), SYSTEM_REMINDER_CLOSE].join('\n')
+}
+
+function withTruncatedContent(file: LoadedInstructionFile, includedBytes: number): LoadedInstructionFile {
+  return { ...file, content: truncateUtf8(file.content, includedBytes) }
+}
+
+function truncateToFit(
+  file: LoadedInstructionFile,
+  includedFiles: LoadedInstructionFile[],
+  maxBytes: number,
+  omitted: InstructionFile[],
+  style: RenderStyle,
+): LoadedInstructionFile {
+  const originalBytes = byteLength(file.content)
+  let low = 0
+  let high = originalBytes
+  let best = withTruncatedContent(file, 0)
+  while (low <= high) {
+    const mid = Math.floor((low + high) / 2)
+    const candidate = withTruncatedContent(file, mid)
+    const truncated = [{ displayPath: file.displayPath, originalBytes, includedBytes: byteLength(candidate.content) }]
+    const text = buildInstructionText([...includedFiles, candidate], maxBytes, omitted, truncated, style)
+    if (byteLength(text) <= maxBytes) {
+      best = candidate
+      low = mid + 1
+    } else {
+      high = mid - 1
+    }
+  }
+  return best
+}
+
+function renderInstructionContext(
+  files: LoadedInstructionFile[],
+  maxBytes: number,
+  style: RenderStyle,
+): RenderedWorkspaceContext {
+  if (maxBytes <= 0 || !Number.isFinite(maxBytes)) return { text: '', omitted: files, truncated: [] }
+
+  const fullText = buildInstructionText(files, maxBytes, [], [], style)
+  if (byteLength(fullText) <= maxBytes) return { text: fullText, omitted: [], truncated: [] }
+
+  for (let start = 1; start < files.length; start += 1) {
+    const included = files.slice(start)
+    const omitted = files.slice(0, start).map(file => ({ absolutePath: file.absolutePath, displayPath: file.displayPath }))
+    const suffixText = buildInstructionText(included, maxBytes, omitted, [], style)
+    if (byteLength(suffixText) <= maxBytes) return { text: suffixText, omitted, truncated: [] }
+  }
+
+  const mostSpecific = files.at(-1)
+  /* v8 ignore next -- callers only reach this after a non-empty fullText was built. */
+  if (mostSpecific === undefined) return { text: '', omitted: [], truncated: [] }
+  const omitted = files.slice(0, -1).map(file => ({ absolutePath: file.absolutePath, displayPath: file.displayPath }))
+
+  for (const candidateStyle of [style, { ...style, intro: COMPACT_WORKSPACE_CONTEXT_INTRO }]) {
+    const truncatedFile = truncateToFit(mostSpecific, [], maxBytes, omitted, candidateStyle)
+    const truncated = [{
+      displayPath: mostSpecific.displayPath,
+      originalBytes: byteLength(mostSpecific.content),
+      includedBytes: byteLength(truncatedFile.content),
+    }]
+    const text = buildInstructionText([truncatedFile], maxBytes, omitted, truncated, candidateStyle)
+    if (byteLength(text) <= maxBytes) return { text, omitted, truncated }
+  }
+
+  const truncated = [{
+    displayPath: mostSpecific.displayPath,
+    originalBytes: byteLength(mostSpecific.content),
+    includedBytes: 0,
+  }]
+  const compactNotice = markerText(maxBytes, omitted, truncated)
+  const compactWithHeading = [compactNotice, style.section(withTruncatedContent(mostSpecific, 0))].join('\n\n')
+  if (byteLength(compactWithHeading) <= maxBytes) return { text: compactWithHeading, omitted, truncated }
+  const text = byteLength(compactNotice) <= maxBytes ? compactNotice : truncateUtf8(compactNotice, maxBytes)
+  return { text, omitted, truncated }
+}
+
+/**
+ * Render the baseline instruction chain with deterministic precedence budgeting.
+ * @param files - loaded files ordered from broadest to most specific.
+ * @param options - rendering byte budget.
+ * @returns bounded baseline prompt text and budget diagnostics.
+ */
+export function renderWorkspaceContext(
+  files: LoadedInstructionFile[],
+  options: { maxBytes: number },
+): RenderedWorkspaceContext {
+  return renderInstructionContext(files, options.maxBytes, BASELINE_RENDER_STYLE)
+}

packages/prompt/workspace-context/src/state.ts

@@ -0,0 +1,301 @@
+import { createHash } from 'node:crypto'
+import type { Agent, HookContext } from '@deepseek-ai/dsh-agent'
+import type { Message } from '@deepseek-ai/dsh-llm'
+import { renderContextContent, type JsonValue } from '@deepseek-ai/dsh-session'
+import type { FileSystem } from '@deepseek-ai/dsh-fs'
+import type { ToolExecution, ToolExecutionResult } from '@deepseek-ai/dsh-tools'
+import type { ResolvedConfig } from './config.ts'
+import {
+  ancestorChain,
+  descendantDirsBetween,
+  findProjectRoot,
+  loadScopeInstruction,
+  relativeDisplay,
+  type InstructionContentCache,
+  type LoadedInstructionFile,
+} from './files.ts'
+import {
+  renderInstructionChanges,
+  scopeForDisplayPath,
+  type ChangeRenderItem,
+  type WorkspaceInstructionChange,
+} from './render.ts'
+
+export const name = 'workspace-context'
+
+const PLUGIN_SOURCE = { kind: 'plugin', plugin: name } as const
+const FILE_TOUCH_TOOL_NAMES = new Set(['read', 'write', 'edit'])
+
+/** Dynamic state waiting for the loop to append its returned context event. */
+export interface PendingInstructionChange {
+  change: WorkspaceInstructionChange
+  afterSeq: number
+}
+
+/** Plugin-owned raw context with required replay metadata. */
+export interface WorkspaceHookContext extends HookContext {
+  envelope: 'raw'
+  meta: JsonValue
+}
+
+function digest(content: string): string {
+  return createHash('sha256').update(content).digest('hex')
+}
+
+function workspaceContextHook(text: string, changes: WorkspaceInstructionChange[]): WorkspaceHookContext {
+  const serializedChanges: JsonValue[] = changes.map(change => ({
+    action: change.action,
+    scope: change.scope,
+    path: change.path,
+    ...change.previousPath !== undefined ? { previousPath: change.previousPath } : {},
+    ...change.digest !== undefined ? { digest: change.digest } : {},
+  }))
+  const meta: JsonValue = { kind: 'workspace-instructions', version: 1, changes: serializedChanges }
+  return { content: [{ type: 'text', text }], source: PLUGIN_SOURCE, envelope: 'raw', meta }
+}
+
+/**
+ * Build the request-prefix message for a rendered baseline.
+ * @param text - complete plugin-owned system-reminder text.
+ * @returns a user-role prefix message.
+ */
+export function workspaceContextMessage(text: string): Message {
+  return { role: 'user', content: [{ type: 'text', text }] }
+}
+
+/**
+ * Preserve workspace state ownership while folding a downstream context contribution.
+ * @param ours - workspace raw context and structured metadata.
+ * @param theirs - optional downstream context with its own envelope semantics.
+ * @returns one workspace-owned context containing both model-visible contributions.
+ */
+export function concatContext(ours: WorkspaceHookContext, theirs: HookContext | undefined): WorkspaceHookContext {
+  if (theirs === undefined) return ours
+  return {
+    ...ours,
+    content: [
+      ...ours.content,
+      ...renderContextContent(theirs.content, theirs.source, theirs.envelope),
+    ],
+  }
+}
+
+function filePathFromExecution(exec: ToolExecution): string | undefined {
+  if (!FILE_TOUCH_TOOL_NAMES.has(exec.name)) return undefined
+  if (typeof exec.arguments !== 'object' || exec.arguments === null) return undefined
+  if (!('file_path' in exec.arguments) || typeof exec.arguments.file_path !== 'string') return undefined
+  const filePath = exec.arguments.file_path.trim()
+  return filePath.length > 0 ? filePath : undefined
+}
+
+function isWorkspaceContextSource(source: unknown): source is typeof PLUGIN_SOURCE {
+  return typeof source === 'object' && source !== null
+    && 'kind' in source && source.kind === 'plugin'
+    && 'plugin' in source && source.plugin === name
+}
+
+function isRecord(value: JsonValue | undefined): value is { [key: string]: JsonValue } {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+}
+
+function workspaceInstructionChanges(meta: JsonValue | undefined): WorkspaceInstructionChange[] {
+  if (!isRecord(meta) || meta.kind !== 'workspace-instructions' || meta.version !== 1 || !Array.isArray(meta.changes)) return []
+  const changes: WorkspaceInstructionChange[] = []
+  for (const value of meta.changes) {
+    if (!isRecord(value)) continue
+    if (value.action !== 'set' && value.action !== 'replace' && value.action !== 'remove') continue
+    if (typeof value.scope !== 'string' || typeof value.path !== 'string') continue
+    if (value.previousPath !== undefined && typeof value.previousPath !== 'string') continue
+    if (value.digest !== undefined && typeof value.digest !== 'string') continue
+    changes.push({
+      action: value.action,
+      scope: value.scope,
+      path: value.path,
+      ...value.previousPath !== undefined ? { previousPath: value.previousPath } : {},
+      ...value.digest !== undefined ? { digest: value.digest } : {},
+    })
+  }
+  return changes
+}
+
+function sameInstructionChange(a: WorkspaceInstructionChange, b: WorkspaceInstructionChange): boolean {
+  return a.action === b.action && a.scope === b.scope && a.path === b.path && a.digest === b.digest
+}
+
+function visibleInstructionChanges(
+  agent: Agent,
+  pending: Map<string, PendingInstructionChange>,
+): Map<string, WorkspaceInstructionChange> {
+  const visibleSeqs = new Set(agent.session.surface.nodes.map(node => node.seq))
+  const visible = new Map<string, WorkspaceInstructionChange>()
+  for (const [seq, event] of agent.session.events.entries()) {
+    if (event.type !== 'context/message' || !isWorkspaceContextSource(event.data.source)) continue
+    const changes = workspaceInstructionChanges(event.data.meta)
+    for (const change of changes) {
+      const waiting = pending.get(change.scope)
+      if (waiting !== undefined && seq >= waiting.afterSeq && sameInstructionChange(waiting.change, change)) {
+        pending.delete(change.scope)
+      }
+      if (visibleSeqs.has(seq)) visible.set(change.scope, change)
+    }
+  }
+  for (const { change } of pending.values()) visible.set(change.scope, change)
+  return visible
+}
+
+/**
+ * Convert retained baseline files into scope/path/digest comparison state.
+ * @param files - baseline files that survived rendering.
+ * @returns latest baseline state keyed by logical scope.
+ */
+export function baselineInstructionChanges(files: LoadedInstructionFile[]): Map<string, WorkspaceInstructionChange> {
+  return new Map(files.map((file) => {
+    const change: WorkspaceInstructionChange = {
+      action: 'set',
+      scope: scopeForDisplayPath(file.displayPath),
+      path: file.displayPath,
+      digest: digest(file.content),
+    }
+    return [change.scope, change]
+  }))
+}
+
+function pendingChangesFor(
+  session: object,
+  pendingBySession: WeakMap<object, Map<string, PendingInstructionChange>>,
+): Map<string, PendingInstructionChange> {
+  let pending = pendingBySession.get(session)
+  if (pending === undefined) {
+    pending = new Map()
+    pendingBySession.set(session, pending)
+  }
+  return pending
+}
+
+function relativeScope(projectRoot: string, dir: string): string {
+  const scope = relativeDisplay(projectRoot, dir)
+  return scope.length === 0 ? '.' : scope
+}
+
+/**
+ * Compare visible/pending state with provider-visible files and render transitions.
+ * @param agent - session owner whose visible surface supplies durable state.
+ * @param resolved - normalized plugin configuration.
+ * @param cache - shared provider-signature content cache.
+ * @param pendingBySession - short pending window before returned context is logged.
+ * @param baselineBySession - frozen baseline comparison state per session.
+ * @param fileSystem - provider used for current file probes.
+ * @param options - touched path and whether baseline scopes should be checked.
+ * @returns a structured context update, or undefined when state is unchanged/unavailable.
+ */
+export async function reconcileInstructionContext(
+  agent: Agent,
+  resolved: ResolvedConfig,
+  cache: InstructionContentCache,
+  pendingBySession: WeakMap<object, Map<string, PendingInstructionChange>>,
+  baselineBySession: WeakMap<object, Map<string, WorkspaceInstructionChange>>,
+  fileSystem: FileSystem,
+  options: { touchedPath?: string; includeBaselineScopes: boolean },
+): Promise<WorkspaceHookContext | undefined> {
+  const session = agent.session
+  const pending = pendingChangesFor(session, pendingBySession)
+  const visible = visibleInstructionChanges(agent, pending)
+  const effective = new Map(baselineBySession.get(session) ?? [])
+  for (const [scope, change] of visible) effective.set(scope, change)
+  /* v8 ignore next -- normal agents carry an absolute session cwd. */
+  const cwd = session.header.cwd ?? process.cwd()
+  const projectRoot = await findProjectRoot(cwd, resolved.projectRootMarkers, fileSystem)
+  const scopes = new Set<string>()
+  if (options.includeBaselineScopes) {
+    scopes.add('user-global')
+    for (const dir of ancestorChain(projectRoot, cwd)) scopes.add(relativeScope(projectRoot, dir))
+  }
+  for (const scope of effective.keys()) scopes.add(scope)
+  if (options.touchedPath !== undefined) {
+    for (const dir of descendantDirsBetween(cwd, options.touchedPath)) scopes.add(relativeScope(projectRoot, dir))
+  }
+
+  const current = new Map<string, LoadedInstructionFile>()
+  const unavailable = new Set<string>()
+  const seenAbsolutePaths = new Set<string>()
+  for (const scope of scopes) {
+    const probe = await loadScopeInstruction(scope, projectRoot, resolved, cache, fileSystem)
+    if (probe.kind === 'unavailable') {
+      unavailable.add(scope)
+      continue
+    }
+    if (probe.kind === 'absent') continue
+    const { file } = probe
+    if (seenAbsolutePaths.has(file.absolutePath)) continue
+    seenAbsolutePaths.add(file.absolutePath)
+    current.set(scope, file)
+  }
+
+  const items: ChangeRenderItem[] = []
+  for (const scope of scopes) {
+    if (unavailable.has(scope)) continue
+    const previous = effective.get(scope)
+    const file = current.get(scope)
+    if (file === undefined) {
+      if (previous !== undefined && previous.action !== 'remove') {
+        items.push({
+          change: { action: 'remove', scope, path: previous.path },
+          file: { absolutePath: `removed:${scope}`, displayPath: previous.path, content: '' },
+        })
+      }
+      continue
+    }
+    const currentDigest = digest(file.content)
+    if (previous !== undefined && previous.action !== 'remove' && previous.path === file.displayPath && previous.digest === currentDigest) continue
+    const action = previous === undefined || previous.action === 'remove' ? 'set' : 'replace'
+    const previousPath = action === 'replace' && previous !== undefined && previous.path !== file.displayPath
+      ? previous.path
+      : undefined
+    items.push({
+      change: {
+        action,
+        scope,
+        path: file.displayPath,
+        ...previousPath === undefined ? {} : { previousPath },
+        digest: currentDigest,
+      },
+      file,
+    })
+  }
+  if (items.length === 0) return undefined
+  const rendered = renderInstructionChanges(items, resolved.maxBytes)
+  if (rendered.text.length === 0 || rendered.changes.length === 0) return undefined
+  for (const change of rendered.changes) pending.set(change.scope, { change, afterSeq: session.seq })
+  return workspaceContextHook(rendered.text, rendered.changes)
+}
+
+/**
+ * Validate a successful structured file touch and reconcile its applicable scopes.
+ * @param agent - optional agent attached to the tool execution.
+ * @param exec - completed tool execution descriptor.
+ * @param result - original tool result before post-execute decisions.
+ * @param resolved - normalized plugin configuration.
+ * @param cache - shared provider-signature content cache.
+ * @param pendingNestedChanges - per-session pending transition maps.
+ * @param baselineInstructionStates - retained baseline comparison state.
+ * @param fileSystem - provider used for current file probes.
+ * @returns a structured context update, or undefined for irrelevant/failed/unchanged calls.
+ */
+export async function dynamicInstructionContext(
+  agent: Agent | undefined,
+  exec: ToolExecution,
+  result: ToolExecutionResult,
+  resolved: ResolvedConfig,
+  cache: InstructionContentCache,
+  pendingNestedChanges: WeakMap<object, Map<string, PendingInstructionChange>>,
+  baselineInstructionStates: WeakMap<object, Map<string, WorkspaceInstructionChange>>,
+  fileSystem: FileSystem,
+): Promise<WorkspaceHookContext | undefined> {
+  if (agent === undefined || result.isError) return undefined
+  const touchedPath = filePathFromExecution(exec)
+  if (touchedPath === undefined) return undefined
+  return reconcileInstructionContext(
+    agent, resolved, cache, pendingNestedChanges, baselineInstructionStates, fileSystem,
+    { touchedPath, includeBaselineScopes: baselineInstructionStates.has(agent.session) },
+  )
+}

packages/prompt/workspace-context/tests/workspace-context.e2e.ts

@@ -0,0 +1,124 @@
+import { mkdtemp, mkdir, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import LlmService from '@deepseek-ai/dsh-llm'
+import SessionStore, { SessionId } from '@deepseek-ai/dsh-session'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import ToolRegistry from '@deepseek-ai/dsh-tools'
+import AgentRegistry, { AgentId } from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import AgentLoop from '@deepseek-ai/dsh-agent-loop'
+import * as LlmDeepSeek from '@deepseek-ai/dsh-llm-deepseek'
+import * as WorkspaceContext from '@deepseek-ai/dsh-workspace-context'
+import LocalFileSystem from '@deepseek-ai/dsh-fs-local'
+import * as ToolFs from '@deepseek-ai/dsh-tool-fs'
+import type { SessionEvent } from '@deepseek-ai/dsh-session'
+
+const PROBE = 'banana-271828'
+const NESTED_PROBE = 'papaya-314159'
+const UPDATED_PROBE = 'guava-161803'
+
+let ctx: Context | undefined
+let workdir: string | undefined
+
+afterEach(async () => {
+  await ctx?.fiber.dispose()
+  ctx = undefined
+  if (workdir !== undefined) await rm(workdir, { recursive: true, force: true })
+  workdir = undefined
+})
+
+async function harness(): Promise<{ ctx: Context; agent: Agent }> {
+  workdir = await mkdtemp(join(tmpdir(), 'dsh-workspace-context-e2e-'))
+  await mkdir(join(workdir, '.git'), { recursive: true })
+  await writeFile(join(workdir, 'AGENTS.md'), `If the user asks for the workspace context handshake, reply with exactly this string and nothing else: ${PROBE}.\n`)
+  ctx = new Context()
+  await ctx.plugin(LlmService)
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(SystemPrompt, { persona: 'Answer the user exactly and concisely.' })
+  await ctx.plugin(ToolRegistry)
+  await ctx.plugin(AgentRegistry)
+  await ctx.plugin(LocalFileSystem, { cwd: '/' })
+  await ctx.plugin(ToolFs)
+  await ctx.plugin(WorkspaceContext)
+  await ctx.plugin(AgentLoop, { agents: [] })
+  await ctx.plugin(LlmDeepSeek, { models: ['deepseek-v4-flash'] })
+  const handle = ctx.agents.create({
+    agentId: AgentId('workspace-context-e2e'),
+    sessionId: SessionId('workspace-context-e2e-session'),
+    meta: { cwd: workdir },
+    agentOptions: { model: 'deepseek-v4-flash' },
+  })
+  return { ctx, agent: handle.agent }
+}
+
+function waitForIdle(ctx: Context, agent: Agent): Promise<void> {
+  return new Promise((resolve) => {
+    const dispose = ctx.on('agent/status', (subject, status) => {
+      if (subject === agent && status === 'idle') {
+        dispose()
+        resolve()
+      }
+    })
+  })
+}
+
+function finalText(events: SessionEvent[]): string {
+  const message = events.findLast(event => event.type === 'assistant/message')
+  if (message?.type !== 'assistant/message') return ''
+  return message.data.content
+    .filter(block => block.type === 'text')
+    .map(block => block.text)
+    .join('')
+}
+
+describe.skipIf(!process.env.DEEPSEEK_API_KEY)('workspace context e2e: real model sees AGENTS.md baseline', () => {
+  it('obeys a probe instruction loaded from the workspace', async () => {
+    const live = await harness()
+
+    live.agent.send([{ type: 'text', text: 'Workspace context handshake?' }])
+    await waitForIdle(live.ctx, live.agent)
+
+    expect(finalText([...live.agent.session.events])).toContain(PROBE)
+  }, 120_000)
+
+  it('loads a nested AGENTS.md after the real read tool touches a descendant file', async () => {
+    const live = await harness()
+    await mkdir(join(workdir!, 'pkg/deep'), { recursive: true })
+    await writeFile(join(workdir!, 'pkg/AGENTS.md'), `If the user asks for the nested instruction handshake, reply with exactly this string and nothing else: ${NESTED_PROBE}.\n`)
+    await writeFile(join(workdir!, 'pkg/deep/file.txt'), 'This file exists only to trigger nested workspace instructions.\n')
+
+    live.agent.send([{ type: 'text', text: 'Use the read tool to inspect pkg/deep/file.txt. After reading it, answer: nested instruction handshake?' }])
+    await waitForIdle(live.ctx, live.agent)
+
+    expect(finalText([...live.agent.session.events])).toContain(NESTED_PROBE)
+  }, 120_000)
+
+  it('appends changed baseline instructions after a real file-tool touch without rewriting the frozen prefix', async () => {
+    const live = await harness()
+    await writeFile(join(workdir!, 'trigger.txt'), 'This file triggers workspace instruction reconciliation.\n')
+    live.agent.send([{ type: 'text', text: 'Workspace context handshake?' }])
+    await waitForIdle(live.ctx, live.agent)
+    await writeFile(join(workdir!, 'AGENTS.md'), `The old workspace handshake no longer applies. If the user asks for the updated workspace context handshake, reply with exactly this string and nothing else: ${UPDATED_PROBE}.\n`)
+
+    live.agent.send([{ type: 'text', text: 'You must use the read tool to inspect trigger.txt. After reading it, answer: updated workspace context handshake?' }])
+    await waitForIdle(live.ctx, live.agent)
+
+    const events = [...live.agent.session.events]
+    const update = events.find(event => event.type === 'context/message'
+      && typeof event.data.meta === 'object'
+      && event.data.meta !== null
+      && !Array.isArray(event.data.meta)
+      && event.data.meta.kind === 'workspace-instructions')
+    expect(update?.type === 'context/message' && update.data.meta).toMatchObject({
+      changes: [{ action: 'replace', scope: '.', path: 'AGENTS.md' }],
+    })
+    const updateText = update?.type === 'context/message'
+      ? update.data.content.filter(block => block.type === 'text').map(block => block.text).join('')
+      : ''
+    expect(updateText).toContain('Updated instructions from: AGENTS.md')
+    expect(finalText(events)).toContain(UPDATED_PROBE)
+  }, 120_000)
+})

packages/prompt/workspace-context/tsconfig.json

@@ -0,0 +1,36 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../../vendor/schemastery"
+    },
+    {
+      "path": "../../llm/llm"
+    },
+    {
+      "path": "../../core/agent"
+    },
+    {
+      "path": "../../core/session"
+    },
+    {
+      "path": "../../core/tools"
+    },
+    {
+      "path": "../../fs/fs"
+    },
+    {
+      "path": "../../util/paths"
+    }
+  ]
+}