diff --git a/assets/agents/team/architect.md b/assets/agents/team/architect.md
index c02643e..bd6262c 100644
--- a/assets/agents/team/architect.md
+++ b/assets/agents/team/architect.md
@@ -79,3 +79,7 @@ permission:
 - 接口定义必须完整（请求参数、响应结构、错误码）
 - 每个任务应是垂直切片，单人 2-4 小时可完成
 - 标注方案中的假设和不确定项
+
+## Project Context
+
+项目根 CONTEXT.md 是领域术语权威（消息中已自动注入内容与 digest）。遵循其中定义的领域术语；发现新术语或冲突时暂停提问。
diff --git a/assets/agents/team/backend.md b/assets/agents/team/backend.md
index 8b92fa8..8d8b7d0 100644
--- a/assets/agents/team/backend.md
+++ b/assets/agents/team/backend.md
@@ -98,3 +98,7 @@ self-report 每个 cycle 的状态，不跳过任何阶段。
 - 不修改与任务无关的文件
 - 不引入未在项目中使用的第三方依赖
 - 不提交硬编码的密钥/配置
+
+## Project Context
+
+项目根 CONTEXT.md 是领域术语权威（消息中已自动注入内容与 digest）。遵循其中定义的领域术语；发现新术语或冲突时暂停提问。
diff --git a/assets/agents/team/goal-verify.md b/assets/agents/team/goal-verify.md
index b7d66da..d259241 100644
--- a/assets/agents/team/goal-verify.md
+++ b/assets/agents/team/goal-verify.md
@@ -52,3 +52,7 @@ permission:
 ---
 
 不创建或修改任何文件。你是只读验证者。
+
+## Project Context
+
+项目根 CONTEXT.md 是领域术语权威（消息中已自动注入内容与 digest）。遵循其中定义的领域术语；发现新术语或冲突时暂停提问。
diff --git a/assets/agents/team/reviewer.md b/assets/agents/team/reviewer.md
index 18ee39d..ecc0cf9 100644
--- a/assets/agents/team/reviewer.md
+++ b/assets/agents/team/reviewer.md
@@ -115,3 +115,7 @@ permission:
 - 不修改代码
 - 每个问题必须给出具体的修复建议
 - 优先关注安全性和正确性
+
+## Project Context
+
+项目根 CONTEXT.md 是领域术语权威（消息中已自动注入内容与 digest）。遵循其中定义的领域术语；发现新术语或冲突时暂停提问。
diff --git a/src/kernel/context.ts b/src/kernel/context.ts
new file mode 100644
index 0000000..4984c2c
--- /dev/null
+++ b/src/kernel/context.ts
@@ -0,0 +1,107 @@
+import { createHash } from "node:crypto"
+import { readFile, stat } from "node:fs/promises"
+import path from "node:path"
+
+/** 注入块内的防重复 marker（message transform 据此跳过已注入的会话） */
+export const CONTEXT_MARKER = "cabbage-project-context"
+
+/** CONTEXT.md 全文注入的行数上限，超长截断并提示 */
+export const MAX_CONTEXT_LINES = 200
+
+export interface ContextDigest {
+  /** 根 CONTEXT.md 的绝对路径 */
+  path: string
+  /** 文件 mtime（毫秒），用于缓存刷新判定 */
+  mtimeMs: number
+  /** sha256(内容) 前 16 位十六进制 */
+  digest: string
+  /** 从 CONTEXT.md 提取的 ## 标题列表 */
+  terms: string[]
+}
+
+export interface ContextBlock extends ContextDigest {
+  /** 可直接注入到 prompt 的块文本 */
+  block: string
+}
+
+let _cache: { projectDir: string; mtimeMs: number; content: string } | null = null
+
+export function resetContextCache(): void {
+  _cache = null
+}
+
+/**
+ * 发现并摘要项目根 CONTEXT.md。
+ * - 缺失 → 返回 null（不报错）
+ * - mtime 变化才重读，否则命中缓存
+ */
+export async function getContextBlock(projectDir: string): Promise<ContextBlock | null> {
+  const filePath = path.join(projectDir, "CONTEXT.md")
+  let stats
+  try {
+    stats = await stat(filePath)
+  } catch {
+    _cache = null
+    return null
+  }
+
+  if (_cache?.projectDir === projectDir && _cache.mtimeMs === stats.mtimeMs) {
+    return buildContextBlock(projectDir, filePath, stats.mtimeMs, _cache.content)
+  }
+
+  const content = await readFile(filePath, "utf8")
+  _cache = { projectDir, mtimeMs: stats.mtimeMs, content }
+  return buildContextBlock(projectDir, filePath, stats.mtimeMs, content)
+}
+
+/** 取注入块文本；无块时返回空串（调用方无需判空） */
+export function formatContextBlock(block: ContextBlock | null): string {
+  return block?.block ?? ""
+}
+
+function buildContextBlock(projectDir: string, filePath: string, mtimeMs: number, content: string): ContextBlock {
+  const digest = createHash("sha256").update(content).digest("hex").slice(0, 16)
+  const terms = extractTerms(content)
+  return {
+    path: filePath,
+    mtimeMs,
+    digest,
+    terms,
+    block: renderBlock(projectDir, filePath, mtimeMs, digest, terms, content),
+  }
+}
+
+function extractTerms(content: string): string[] {
+  const terms: string[] = []
+  for (const line of content.split("\n")) {
+    const match = /^##\s+(.+)$/.exec(line)
+    if (match) terms.push(match[1].trim())
+  }
+  return terms
+}
+
+function renderBlock(
+  projectDir: string,
+  filePath: string,
+  mtimeMs: number,
+  digest: string,
+  terms: string[],
+  content: string,
+): string {
+  const lines = content.split("\n")
+  const truncated = lines.length > MAX_CONTEXT_LINES
+  const body = truncated ? lines.slice(0, MAX_CONTEXT_LINES).join("\n") : content
+
+  const header = [
+    "## Project Context (auto-injected)",
+    `<!-- ${CONTEXT_MARKER} -->`,
+    `来源: ${path.relative(projectDir, filePath)} · mtime: ${new Date(mtimeMs).toISOString()} · digest: ${digest}`,
+    terms.length > 0 ? `主题: ${terms.join(", ")}` : "",
+  ].filter(Boolean).join("\n")
+
+  const truncationNote = truncated
+    ? `\n\n> ⚠️ CONTEXT.md 超过 ${MAX_CONTEXT_LINES} 行，已截断。请直接读取完整文件。`
+    : ""
+
+  return `${header}\n\n${body}${truncationNote}`
+}
diff --git a/src/plugin/server.ts b/src/plugin/server.ts
index 70ebe58..6dcbdf0 100644
--- a/src/plugin/server.ts
+++ b/src/plugin/server.ts
@@ -21,11 +21,35 @@ import {
 } from "../flowrun/transitions.js"
 import type { TaskExecutionBinding, FlowControlResponse } from "../flowrun/types.js"
 import { readFlowRun } from "../flowrun/github.js"
+import { getContextBlock, formatContextBlock, CONTEXT_MARKER } from "../kernel/context.js"
+import type { ContextBlock } from "../kernel/context.js"
 
 const abortedSessions = new Set<string>()
 const errorRetryCount = new Map<string, number>()
 const COMPACTION_THRESHOLD = 20
 
+export interface FirstUserInjectionInput {
+  hasGoal: boolean
+  isSubAgent: boolean
+  contextBlock: ContextBlock | null
+  bootstrap: string
+}
+
+/**
+ * 决定首条 user 消息注入内容：
+ * - Primary（goal 激活）→ bootstrap + Project Context 块
+ * - 子 agent → 仅 Project Context 块
+ * - 其他 → 不注入
+ */
+export function buildFirstUserInjection(input: FirstUserInjectionInput): string | null {
+  const parts: string[] = []
+  if (input.hasGoal) parts.push(input.bootstrap)
+  if (input.contextBlock && (input.hasGoal || input.isSubAgent)) {
+    parts.push(input.contextBlock.block)
+  }
+  return parts.length > 0 ? parts.join("\n\n") : null
+}
+
 interface V1ClientContainer {
   _client?: { getConfig?: () => Record<string, unknown> }
 }
@@ -120,9 +144,12 @@ async function queueContinuation(
       } catch {}
     }
 
+    const contextBlock = projectDir ? await getContextBlock(projectDir) : null
+    const contextText = contextBlock ? `${formatContextBlock(contextBlock)}\n\n` : ""
+
     await client.session.promptAsync({
       sessionID,
-      parts: [{ type: "text" as const, text: continuationPrompt(goal.objective, goal.completionCriterion), synthetic: true }],
+      parts: [{ type: "text" as const, text: contextText + continuationPrompt(goal.objective, goal.completionCriterion), synthetic: true }],
     })
   } catch (err) {
     console.error("[cabbage] continuation failed:", err)
@@ -538,13 +565,21 @@ export function createOpencodeCabbage(packageRoot: string): Plugin {
         const firstUser = output.messages.find(m => m.info.role === "user")
         if (!firstUser || !firstUser.parts.length) return
 
-        if (firstUser.parts.some(p => p.type === "text" && p.text.includes("EXTREMELY_IMPORTANT"))) return
+        if (firstUser.parts.some(p => p.type === "text" && (p.text.includes("EXTREMELY_IMPORTANT") || p.text.includes(CONTEXT_MARKER)))) return
 
-        // Only inject bootstrap for active flow: goal is active or user sent a flow command
-        const hasGoal = await readGoal(goalClient, output.messages[0].info.sessionID).then(r => r.goal?.status === "active").catch(() => false)
-        if (!hasGoal) return
+        const sessionID = output.messages[0].info.sessionID as string
+        const { goal, session } = await readGoal(goalClient, sessionID)
+        const contextBlock = await getContextBlock(projectDir)
 
-        firstUser.parts.unshift({ type: "text", text: getBootstrapContent() } as typeof firstUser.parts[number])
+        const injection = buildFirstUserInjection({
+          hasGoal: goal?.status === "active",
+          isSubAgent: !!session?.parentID,
+          contextBlock,
+          bootstrap: getBootstrapContent(),
+        })
+        if (injection) {
+          firstUser.parts.unshift({ type: "text", text: injection } as typeof firstUser.parts[number])
+        }
       },
 
       async event({ event }) {
diff --git a/test/kernel/context.test.ts b/test/kernel/context.test.ts
new file mode 100644
index 0000000..9c3d0ba
--- /dev/null
+++ b/test/kernel/context.test.ts
@@ -0,0 +1,129 @@
+import { describe, it, expect, beforeEach, afterEach } from "vitest"
+import { createHash } from "node:crypto"
+import { mkdtemp, stat, utimes, writeFile, rm } from "node:fs/promises"
+import os from "node:os"
+import path from "node:path"
+
+import {
+  getContextBlock,
+  resetContextCache,
+  formatContextBlock,
+  CONTEXT_MARKER,
+  MAX_CONTEXT_LINES,
+} from "../../src/kernel/context.js"
+
+let tmpDir: string
+
+beforeEach(async () => {
+  tmpDir = await mkdtemp(path.join(os.tmpdir(), "cabbage-context-"))
+  resetContextCache()
+})
+
+afterEach(async () => {
+  resetContextCache()
+  await rm(tmpDir, { recursive: true, force: true })
+})
+
+function sha16(content: string): string {
+  return createHash("sha256").update(content).digest("hex").slice(0, 16)
+}
+
+describe("getContextBlock — 发现与摘要", () => {
+  it("发现根 CONTEXT.md 并返回 path/mtime/digest/terms", async () => {
+    const content = "## Terms\n- user\n- agent\n"
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), content, "utf8")
+
+    const block = await getContextBlock(tmpDir)
+
+    expect(block).not.toBeNull()
+    expect(block!.path).toBe(path.join(tmpDir, "CONTEXT.md"))
+    expect(block!.mtimeMs).toBeGreaterThan(0)
+    expect(block!.digest).toBe(sha16(content))
+    expect(block!.terms).toEqual(["Terms"])
+  })
+
+  it("CONTEXT.md 缺失时返回 null 且不报错", async () => {
+    expect(await getContextBlock(tmpDir)).toBeNull()
+  })
+
+  it("digest 稳定：同内容两次调用 digest 一致", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\nsame\n", "utf8")
+
+    const first = await getContextBlock(tmpDir)
+    const second = await getContextBlock(tmpDir)
+
+    expect(first!.digest).toBe(second!.digest)
+  })
+
+  it("提取全部 ## 标题为 terms", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\n## Roles\n## Workflow\n", "utf8")
+
+    const block = await getContextBlock(tmpDir)
+
+    expect(block!.terms).toEqual(["Terms", "Roles", "Workflow"])
+  })
+})
+
+describe("getContextBlock — mtime 缓存刷新", () => {
+  it("mtime 变化后重读并刷新 digest", async () => {
+    const file = path.join(tmpDir, "CONTEXT.md")
+    await writeFile(file, "## v1\n", "utf8")
+    const first = await getContextBlock(tmpDir)
+
+    await writeFile(file, "## v2\nnew term\n", "utf8")
+    const stats = await stat(file)
+    await utimes(file, stats.atime, new Date(stats.mtimeMs + 5000))
+
+    const second = await getContextBlock(tmpDir)
+
+    expect(second!.digest).not.toBe(first!.digest)
+    expect(second!.terms).toEqual(["v2"])
+  })
+
+  it("mtime 不变时命中缓存（内容变化也不重读）", async () => {
+    const file = path.join(tmpDir, "CONTEXT.md")
+    const fixedMtime = new Date(1_000_000_000_000) // 固定整数毫秒，可精确还原
+    await writeFile(file, "## cached\n", "utf8")
+    await utimes(file, new Date(), fixedMtime)
+    const first = await getContextBlock(tmpDir)
+
+    // 内容变化但把 mtime 还原 → 应命中缓存
+    await writeFile(file, "## changed\n", "utf8")
+    await utimes(file, new Date(), fixedMtime)
+
+    const second = await getContextBlock(tmpDir)
+
+    expect(second!.digest).toBe(first!.digest)
+  })
+})
+
+describe("formatContextBlock — 注入块格式", () => {
+  it("包含 marker、来源、digest 与全文", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\n- user\n", "utf8")
+    const block = await getContextBlock(tmpDir)
+
+    const text = formatContextBlock(block!)
+
+    expect(text).toContain(CONTEXT_MARKER)
+    expect(text).toContain("Project Context (auto-injected)")
+    expect(text).toContain("CONTEXT.md")
+    expect(text).toContain(block!.digest)
+    expect(text).toContain("## Terms")
+    expect(text).toContain("- user")
+  })
+
+  it("超长文件截断并提示", async () => {
+    const lines = Array.from({ length: MAX_CONTEXT_LINES + 50 }, (_, i) => `line ${i}`)
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), lines.join("\n"), "utf8")
+    const block = await getContextBlock(tmpDir)
+
+    const text = formatContextBlock(block!)
+
+    expect(text).toContain("截断")
+    expect(text).not.toContain(`line ${MAX_CONTEXT_LINES + 49}`)
+  })
+
+  it("CONTEXT.md 缺失时 format 返回空字符串", () => {
+    expect(formatContextBlock(null)).toBe("")
+  })
+})
diff --git a/test/plugin/server-context.test.ts b/test/plugin/server-context.test.ts
new file mode 100644
index 0000000..b1ac2b2
--- /dev/null
+++ b/test/plugin/server-context.test.ts
@@ -0,0 +1,171 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest"
+import { mkdtemp, writeFile, rm } from "node:fs/promises"
+import os from "node:os"
+import path from "node:path"
+import { fileURLToPath } from "node:url"
+
+const mockSessionGet = vi.fn()
+const mockPromptAsync = vi.fn()
+
+vi.mock("../../src/plugin/goal.js", async () => {
+  const actual = await vi.importActual("../../src/plugin/goal.js")
+  return {
+    ...actual,
+    createGoalClient: () => ({
+      session: {
+        get: (...args: unknown[]) => mockSessionGet(...args),
+        update: vi.fn(),
+        promptAsync: (...args: unknown[]) => mockPromptAsync(...args),
+      },
+    }),
+  }
+})
+
+import { createOpencodeCabbage, buildFirstUserInjection } from "../../src/plugin/server.js"
+import { resetContextCache, CONTEXT_MARKER } from "../../src/kernel/context.js"
+
+const projectRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..")
+const ACTIVE_GOAL = {
+  data: {
+    parentID: null,
+    metadata: {
+      goal: { objective: "test", completionCriterion: "pass", status: "active", continuationCount: 0 },
+    },
+  },
+}
+const SUBAGENT_SESSION = { data: { parentID: "parent-1", metadata: {} } }
+const PLAIN_SESSION = { data: { parentID: null, metadata: {} } }
+
+type Transform = (input: unknown, output: { messages: unknown[] }) => Promise<void>
+
+let tmpDir: string
+let transform: Transform
+
+async function makeOutput(sessionID = "sess-1", text = "hello") {
+  return {
+    messages: [
+      { info: { role: "user", sessionID }, parts: [{ type: "text", text }] },
+    ],
+  }
+}
+
+beforeEach(async () => {
+  tmpDir = await mkdtemp(path.join(os.tmpdir(), "cabbage-server-context-"))
+  resetContextCache()
+  process.env.CABBAGE_SKILLS_DIR = path.join(tmpDir, "skills")
+  mockSessionGet.mockReset()
+  mockPromptAsync.mockReset()
+
+  const ctx = {
+    worktree: tmpDir,
+    directory: tmpDir,
+    client: { _client: { getConfig: () => ({}) } },
+    serverUrl: new URL("http://localhost:0"),
+  }
+  const plugin = await createOpencodeCabbage(projectRoot)(ctx as never, {})
+  transform = plugin["experimental.chat.messages.transform"] as Transform
+})
+
+afterEach(async () => {
+  resetContextCache()
+  delete process.env.CABBAGE_SKILLS_DIR
+  await rm(tmpDir, { recursive: true, force: true })
+})
+
+describe("buildFirstUserInjection — 注入决策", () => {
+  const bootstrap = "<EXTREMELY_IMPORTANT>bootstrap content</EXTREMELY_IMPORTANT>"
+  const contextBlock = {
+    path: "/tmp/CONTEXT.md",
+    mtimeMs: 1,
+    digest: "abc123",
+    terms: ["Terms"],
+    block: `## Project Context (auto-injected)\n<!-- ${CONTEXT_MARKER} -->\n...`,
+  }
+
+  it("Primary（goal 激活）注入 bootstrap + context", () => {
+    const text = buildFirstUserInjection({ hasGoal: true, isSubAgent: false, contextBlock, bootstrap })
+    expect(text).toContain(bootstrap)
+    expect(text).toContain(CONTEXT_MARKER)
+  })
+
+  it("Primary 无 CONTEXT.md 时仅注入 bootstrap", () => {
+    const text = buildFirstUserInjection({ hasGoal: true, isSubAgent: false, contextBlock: null, bootstrap })
+    expect(text).toBe(bootstrap)
+  })
+
+  it("子 agent 注入 context 但不注入 bootstrap", () => {
+    const text = buildFirstUserInjection({ hasGoal: false, isSubAgent: true, contextBlock, bootstrap })
+    expect(text).toContain(CONTEXT_MARKER)
+    expect(text).not.toContain("EXTREMELY_IMPORTANT")
+  })
+
+  it("goal 未激活且非子 agent → 不注入", () => {
+    const text = buildFirstUserInjection({ hasGoal: false, isSubAgent: false, contextBlock, bootstrap })
+    expect(text).toBeNull()
+  })
+
+  it("子 agent 无 CONTEXT.md → 不注入", () => {
+    const text = buildFirstUserInjection({ hasGoal: false, isSubAgent: true, contextBlock: null, bootstrap })
+    expect(text).toBeNull()
+  })
+})
+
+describe("message.transform — 注入接线", () => {
+  it("Primary 首消息注入 bootstrap + Project Context 块", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\n- user\n", "utf8")
+    mockSessionGet.mockResolvedValue(ACTIVE_GOAL)
+
+    const output = await makeOutput()
+    await transform({}, output)
+
+    const text = (output.messages[0].parts[0] as { text: string }).text
+    expect(text).toContain("EXTREMELY_IMPORTANT")
+    expect(text).toContain("Project Context (auto-injected)")
+    expect(text).toContain(CONTEXT_MARKER)
+  })
+
+  it("子 agent 首消息注入 Project Context 块（无 bootstrap）", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\n- agent\n", "utf8")
+    mockSessionGet.mockResolvedValue(SUBAGENT_SESSION)
+
+    const output = await makeOutput()
+    await transform({}, output)
+
+    const text = (output.messages[0].parts[0] as { text: string }).text
+    expect(text).toContain("Project Context (auto-injected)")
+    expect(text).toContain(CONTEXT_MARKER)
+    expect(text).not.toContain("EXTREMELY_IMPORTANT")
+  })
+
+  it("goal 未激活且非子 agent 不注入", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\n- user\n", "utf8")
+    mockSessionGet.mockResolvedValue(PLAIN_SESSION)
+
+    const output = await makeOutput()
+    await transform({}, output)
+
+    expect(output.messages[0].parts).toHaveLength(1)
+    expect((output.messages[0].parts[0] as { text: string }).text).toBe("hello")
+  })
+
+  it("CONTEXT.md 缺失时不报错，Primary 仍注入 bootstrap", async () => {
+    mockSessionGet.mockResolvedValue(ACTIVE_GOAL)
+
+    const output = await makeOutput()
+    await transform({}, output)
+
+    const text = (output.messages[0].parts[0] as { text: string }).text
+    expect(text).toContain("EXTREMELY_IMPORTANT")
+    expect(text).not.toContain(CONTEXT_MARKER)
+  })
+
+  it("已含注入 marker 的会话不重复注入", async () => {
+    await writeFile(path.join(tmpDir, "CONTEXT.md"), "## Terms\n- user\n", "utf8")
+    mockSessionGet.mockResolvedValue(ACTIVE_GOAL)
+
+    const output = await makeOutput("sess-1", `already injected <!-- ${CONTEXT_MARKER} -->`)
+    await transform({}, output)
+
+    expect(output.messages[0].parts).toHaveLength(1)
+  })
+})