diff --git a/src/tools/agent-teams/inbox-store.ts b/src/tools/agent-teams/inbox-store.ts
new file mode 100644
index 000000000..b351db1cd
--- /dev/null
+++ b/src/tools/agent-teams/inbox-store.ts
@@ -0,0 +1,139 @@
+import { existsSync, readFileSync, writeFileSync } from "node:fs"
+import { z } from "zod"
+import { acquireLock, ensureDir } from "../../features/claude-tasks/storage"
+import { getTeamInboxDir, getTeamInboxPath } from "./paths"
+import { TeamInboxMessage, TeamInboxMessageSchema } from "./types"
+
+const TeamInboxListSchema = z.array(TeamInboxMessageSchema)
+
+function nowIso(): string {
+  return new Date().toISOString()
+}
+
+function withInboxLock<T>(teamName: string, operation: () => T): T {
+  const inboxDir = getTeamInboxDir(teamName)
+  ensureDir(inboxDir)
+  const lock = acquireLock(inboxDir)
+  if (!lock.acquired) {
+    throw new Error("inbox_lock_unavailable")
+  }
+
+  try {
+    return operation()
+  } finally {
+    lock.release()
+  }
+}
+
+function parseInboxFile(content: string): TeamInboxMessage[] {
+  try {
+    const parsed = JSON.parse(content)
+    const result = TeamInboxListSchema.safeParse(parsed)
+    return result.success ? result.data : []
+  } catch {
+    return []
+  }
+}
+
+function readInboxMessages(teamName: string, agentName: string): TeamInboxMessage[] {
+  const path = getTeamInboxPath(teamName, agentName)
+  if (!existsSync(path)) {
+    return []
+  }
+  return parseInboxFile(readFileSync(path, "utf-8"))
+}
+
+function writeInboxMessages(teamName: string, agentName: string, messages: TeamInboxMessage[]): void {
+  const path = getTeamInboxPath(teamName, agentName)
+  writeFileSync(path, JSON.stringify(messages), "utf-8")
+}
+
+export function ensureInbox(teamName: string, agentName: string): void {
+  withInboxLock(teamName, () => {
+    const path = getTeamInboxPath(teamName, agentName)
+    if (!existsSync(path)) {
+      writeFileSync(path, "[]", "utf-8")
+    }
+  })
+}
+
+export function appendInboxMessage(teamName: string, agentName: string, message: TeamInboxMessage): void {
+  withInboxLock(teamName, () => {
+    const path = getTeamInboxPath(teamName, agentName)
+    if (!existsSync(path)) {
+      writeFileSync(path, "[]", "utf-8")
+    }
+    const messages = readInboxMessages(teamName, agentName)
+    messages.push(TeamInboxMessageSchema.parse(message))
+    writeInboxMessages(teamName, agentName, messages)
+  })
+}
+
+export function sendPlainInboxMessage(
+  teamName: string,
+  from: string,
+  to: string,
+  text: string,
+  summary: string,
+  color?: string,
+): void {
+  appendInboxMessage(teamName, to, {
+    from,
+    text,
+    timestamp: nowIso(),
+    read: false,
+    summary,
+    ...(color ? { color } : {}),
+  })
+}
+
+export function sendStructuredInboxMessage(
+  teamName: string,
+  from: string,
+  to: string,
+  payload: Record<string, unknown>,
+  summary?: string,
+): void {
+  appendInboxMessage(teamName, to, {
+    from,
+    text: JSON.stringify(payload),
+    timestamp: nowIso(),
+    read: false,
+    ...(summary ? { summary } : {}),
+  })
+}
+
+export function readInbox(
+  teamName: string,
+  agentName: string,
+  unreadOnly = false,
+  markAsRead = true,
+): TeamInboxMessage[] {
+  return withInboxLock(teamName, () => {
+    const messages = readInboxMessages(teamName, agentName)
+
+    const selected = unreadOnly ? messages.filter((message) => !message.read) : [...messages]
+
+    if (!markAsRead || selected.length === 0) {
+      return selected
+    }
+
+    const updated = messages.map((message) => {
+      if (!unreadOnly) {
+        return { ...message, read: true }
+      }
+
+      if (selected.some((selectedMessage) => selectedMessage.timestamp === message.timestamp && selectedMessage.from === message.from && selectedMessage.text === message.text)) {
+        return { ...message, read: true }
+      }
+      return message
+    })
+
+    writeInboxMessages(teamName, agentName, updated)
+    return selected
+  })
+}
+
+export function buildShutdownRequestId(recipient: string): string {
+  return `shutdown-${Date.now()}@${recipient}`
+}
diff --git a/src/tools/agent-teams/index.ts b/src/tools/agent-teams/index.ts
new file mode 100644
index 000000000..2b66c3710
--- /dev/null
+++ b/src/tools/agent-teams/index.ts
@@ -0,0 +1 @@
+export { createAgentTeamsTools } from "./tools"
diff --git a/src/tools/agent-teams/messaging-tools.ts b/src/tools/agent-teams/messaging-tools.ts
new file mode 100644
index 000000000..6608a0978
--- /dev/null
+++ b/src/tools/agent-teams/messaging-tools.ts
@@ -0,0 +1,199 @@
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+import type { BackgroundManager } from "../../features/background-agent"
+import { buildShutdownRequestId, readInbox, sendPlainInboxMessage, sendStructuredInboxMessage } from "./inbox-store"
+import { getTeamMember, listTeammates, readTeamConfigOrThrow } from "./team-config-store"
+import { resumeTeammateWithMessage } from "./teammate-runtime"
+import {
+  TeamReadInboxInputSchema,
+  TeamSendMessageInputSchema,
+  TeamToolContext,
+  isTeammateMember,
+} from "./types"
+
+function nowIso(): string {
+  return new Date().toISOString()
+}
+
+export function createSendMessageTool(manager: BackgroundManager): ToolDefinition {
+  return tool({
+    description: "Send direct or broadcast team messages and protocol responses.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      type: tool.schema.enum(["message", "broadcast", "shutdown_request", "shutdown_response", "plan_approval_response"]),
+      recipient: tool.schema.string().optional().describe("Message recipient"),
+      content: tool.schema.string().optional().describe("Message body"),
+      summary: tool.schema.string().optional().describe("Short summary"),
+      request_id: tool.schema.string().optional().describe("Protocol request id"),
+      approve: tool.schema.boolean().optional().describe("Approval flag"),
+      sender: tool.schema.string().optional().describe("Sender name (default: team-lead)"),
+    },
+    execute: async (args: Record<string, unknown>, context: TeamToolContext): Promise<string> => {
+      try {
+        const input = TeamSendMessageInputSchema.parse(args)
+        const sender = input.sender ?? "team-lead"
+        const config = readTeamConfigOrThrow(input.team_name)
+        const memberNames = new Set(config.members.map((member) => member.name))
+
+        if (input.type === "message") {
+          if (!input.recipient || !input.summary || !input.content) {
+            return JSON.stringify({ error: "message_requires_recipient_summary_content" })
+          }
+          if (!memberNames.has(input.recipient)) {
+            return JSON.stringify({ error: "message_recipient_not_found" })
+          }
+
+          const targetMember = getTeamMember(config, input.recipient)
+          const color = targetMember && isTeammateMember(targetMember) ? targetMember.color : undefined
+          sendPlainInboxMessage(input.team_name, sender, input.recipient, input.content, input.summary, color)
+
+          if (targetMember && isTeammateMember(targetMember)) {
+            await resumeTeammateWithMessage(manager, context, input.team_name, targetMember, input.summary, input.content)
+          }
+
+          return JSON.stringify({ success: true, message: `message_sent:${input.recipient}` })
+        }
+
+        if (input.type === "broadcast") {
+          if (!input.summary) {
+            return JSON.stringify({ error: "broadcast_requires_summary" })
+          }
+          const teammates = listTeammates(config)
+          for (const teammate of teammates) {
+            sendPlainInboxMessage(input.team_name, sender, teammate.name, input.content ?? "", input.summary)
+            await resumeTeammateWithMessage(manager, context, input.team_name, teammate, input.summary, input.content ?? "")
+          }
+          return JSON.stringify({ success: true, message: `broadcast_sent:${teammates.length}` })
+        }
+
+        if (input.type === "shutdown_request") {
+          if (!input.recipient) {
+            return JSON.stringify({ error: "shutdown_request_requires_recipient" })
+          }
+          if (input.recipient === "team-lead") {
+            return JSON.stringify({ error: "cannot_shutdown_team_lead" })
+          }
+          const targetMember = getTeamMember(config, input.recipient)
+          if (!targetMember || !isTeammateMember(targetMember)) {
+            return JSON.stringify({ error: "shutdown_recipient_not_found" })
+          }
+
+          const requestId = buildShutdownRequestId(input.recipient)
+          sendStructuredInboxMessage(
+            input.team_name,
+            "team-lead",
+            input.recipient,
+            {
+              type: "shutdown_request",
+              requestId,
+              from: "team-lead",
+              reason: input.content ?? "",
+              timestamp: nowIso(),
+            },
+            "shutdown_request",
+          )
+
+          await resumeTeammateWithMessage(
+            manager,
+            context,
+            input.team_name,
+            targetMember,
+            "shutdown_request",
+            input.content ?? "Shutdown requested",
+          )
+
+          return JSON.stringify({ success: true, request_id: requestId, target: input.recipient })
+        }
+
+        if (input.type === "shutdown_response") {
+          if (!input.request_id) {
+            return JSON.stringify({ error: "shutdown_response_requires_request_id" })
+          }
+          if (input.approve) {
+            sendStructuredInboxMessage(
+              input.team_name,
+              sender,
+              "team-lead",
+              {
+                type: "shutdown_approved",
+                requestId: input.request_id,
+                from: sender,
+                timestamp: nowIso(),
+                backendType: "native",
+              },
+              "shutdown_approved",
+            )
+            return JSON.stringify({ success: true, message: `shutdown_approved:${input.request_id}` })
+          }
+
+          sendPlainInboxMessage(
+            input.team_name,
+            sender,
+            "team-lead",
+            input.content ?? "Shutdown rejected",
+            "shutdown_rejected",
+          )
+          return JSON.stringify({ success: true, message: `shutdown_rejected:${input.request_id}` })
+        }
+
+        if (!input.recipient) {
+          return JSON.stringify({ error: "plan_response_requires_recipient" })
+        }
+        if (!memberNames.has(input.recipient)) {
+          return JSON.stringify({ error: "plan_response_recipient_not_found" })
+        }
+
+        if (input.approve) {
+          sendStructuredInboxMessage(
+            input.team_name,
+            sender,
+            input.recipient,
+            {
+              type: "plan_approval",
+              approved: true,
+              requestId: input.request_id,
+            },
+            "plan_approved",
+          )
+          return JSON.stringify({ success: true, message: `plan_approved:${input.recipient}` })
+        }
+
+        sendPlainInboxMessage(
+          input.team_name,
+          sender,
+          input.recipient,
+          input.content ?? "Plan rejected",
+          "plan_rejected",
+        )
+        return JSON.stringify({ success: true, message: `plan_rejected:${input.recipient}` })
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "send_message_failed" })
+      }
+    },
+  })
+}
+
+export function createReadInboxTool(): ToolDefinition {
+  return tool({
+    description: "Read inbox messages for a team member.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      agent_name: tool.schema.string().describe("Member name"),
+      unread_only: tool.schema.boolean().optional().describe("Return only unread messages"),
+      mark_as_read: tool.schema.boolean().optional().describe("Mark returned messages as read"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamReadInboxInputSchema.parse(args)
+        const messages = readInbox(
+          input.team_name,
+          input.agent_name,
+          input.unread_only ?? false,
+          input.mark_as_read ?? true,
+        )
+        return JSON.stringify(messages)
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "read_inbox_failed" })
+      }
+    },
+  })
+}
diff --git a/src/tools/agent-teams/name-validation.ts b/src/tools/agent-teams/name-validation.ts
new file mode 100644
index 000000000..10d868fae
--- /dev/null
+++ b/src/tools/agent-teams/name-validation.ts
@@ -0,0 +1,29 @@
+const VALID_NAME_RE = /^[A-Za-z0-9_-]+$/
+const MAX_NAME_LENGTH = 64
+
+function validateName(value: string, label: "team" | "agent"): string | null {
+  if (!value || !value.trim()) {
+    return `${label}_name_required`
+  }
+
+  if (!VALID_NAME_RE.test(value)) {
+    return `${label}_name_invalid`
+  }
+
+  if (value.length > MAX_NAME_LENGTH) {
+    return `${label}_name_too_long`
+  }
+
+  return null
+}
+
+export function validateTeamName(teamName: string): string | null {
+  return validateName(teamName, "team")
+}
+
+export function validateAgentName(agentName: string): string | null {
+  if (agentName === "team-lead") {
+    return "agent_name_reserved"
+  }
+  return validateName(agentName, "agent")
+}
diff --git a/src/tools/agent-teams/paths.ts b/src/tools/agent-teams/paths.ts
new file mode 100644
index 000000000..9902fb07d
--- /dev/null
+++ b/src/tools/agent-teams/paths.ts
@@ -0,0 +1,40 @@
+import { join } from "node:path"
+import { getOpenCodeConfigDir } from "../../shared/opencode-config-dir"
+
+const AGENT_TEAMS_DIR = "agent-teams"
+
+export function getAgentTeamsRootDir(): string {
+  return join(getOpenCodeConfigDir({ binary: "opencode" }), AGENT_TEAMS_DIR)
+}
+
+export function getTeamsRootDir(): string {
+  return join(getAgentTeamsRootDir(), "teams")
+}
+
+export function getTeamTasksRootDir(): string {
+  return join(getAgentTeamsRootDir(), "tasks")
+}
+
+export function getTeamDir(teamName: string): string {
+  return join(getTeamsRootDir(), teamName)
+}
+
+export function getTeamConfigPath(teamName: string): string {
+  return join(getTeamDir(teamName), "config.json")
+}
+
+export function getTeamInboxDir(teamName: string): string {
+  return join(getTeamDir(teamName), "inboxes")
+}
+
+export function getTeamInboxPath(teamName: string, agentName: string): string {
+  return join(getTeamInboxDir(teamName), `${agentName}.json`)
+}
+
+export function getTeamTaskDir(teamName: string): string {
+  return join(getTeamTasksRootDir(), teamName)
+}
+
+export function getTeamTaskPath(teamName: string, taskId: string): string {
+  return join(getTeamTaskDir(teamName), `${taskId}.json`)
+}
diff --git a/src/tools/agent-teams/team-config-store.ts b/src/tools/agent-teams/team-config-store.ts
new file mode 100644
index 000000000..e5a3d3ca0
--- /dev/null
+++ b/src/tools/agent-teams/team-config-store.ts
@@ -0,0 +1,159 @@
+import { existsSync, rmSync } from "node:fs"
+import {
+  acquireLock,
+  ensureDir,
+  readJsonSafe,
+  writeJsonAtomic,
+} from "../../features/claude-tasks/storage"
+import {
+  getTeamConfigPath,
+  getTeamDir,
+  getTeamInboxDir,
+  getTeamTaskDir,
+  getTeamTasksRootDir,
+  getTeamsRootDir,
+} from "./paths"
+import {
+  TEAM_COLOR_PALETTE,
+  TeamConfig,
+  TeamConfigSchema,
+  TeamLeadMember,
+  TeamMember,
+  TeamTeammateMember,
+  isTeammateMember,
+} from "./types"
+
+function nowMs(): number {
+  return Date.now()
+}
+
+function withTeamLock<T>(teamName: string, operation: () => T): T {
+  const teamDir = getTeamDir(teamName)
+  ensureDir(teamDir)
+  const lock = acquireLock(teamDir)
+  if (!lock.acquired) {
+    throw new Error("team_lock_unavailable")
+  }
+
+  try {
+    return operation()
+  } finally {
+    lock.release()
+  }
+}
+
+function createLeadMember(teamName: string, leadSessionId: string, cwd: string, model: string): TeamLeadMember {
+  return {
+    agentId: `team-lead@${teamName}`,
+    name: "team-lead",
+    agentType: "team-lead",
+    model,
+    joinedAt: nowMs(),
+    cwd,
+    subscriptions: [],
+  }
+}
+
+export function ensureTeamStorageDirs(teamName: string): void {
+  ensureDir(getTeamsRootDir())
+  ensureDir(getTeamTasksRootDir())
+  ensureDir(getTeamDir(teamName))
+  ensureDir(getTeamInboxDir(teamName))
+  ensureDir(getTeamTaskDir(teamName))
+}
+
+export function teamExists(teamName: string): boolean {
+  return existsSync(getTeamConfigPath(teamName))
+}
+
+export function createTeamConfig(
+  teamName: string,
+  description: string,
+  leadSessionId: string,
+  cwd: string,
+  model: string,
+): TeamConfig {
+  ensureTeamStorageDirs(teamName)
+
+  if (teamExists(teamName)) {
+    throw new Error("team_already_exists")
+  }
+
+  const leadAgentId = `team-lead@${teamName}`
+  const config: TeamConfig = {
+    name: teamName,
+    description,
+    createdAt: nowMs(),
+    leadAgentId,
+    leadSessionId,
+    members: [createLeadMember(teamName, leadSessionId, cwd, model)],
+  }
+
+  return withTeamLock(teamName, () => {
+    writeJsonAtomic(getTeamConfigPath(teamName), TeamConfigSchema.parse(config))
+    return config
+  })
+}
+
+export function readTeamConfig(teamName: string): TeamConfig | null {
+  return readJsonSafe(getTeamConfigPath(teamName), TeamConfigSchema)
+}
+
+export function readTeamConfigOrThrow(teamName: string): TeamConfig {
+  const config = readTeamConfig(teamName)
+  if (!config) {
+    throw new Error("team_not_found")
+  }
+  return config
+}
+
+export function writeTeamConfig(teamName: string, config: TeamConfig): TeamConfig {
+  return withTeamLock(teamName, () => {
+    const validated = TeamConfigSchema.parse(config)
+    writeJsonAtomic(getTeamConfigPath(teamName), validated)
+    return validated
+  })
+}
+
+export function listTeammates(config: TeamConfig): TeamTeammateMember[] {
+  return config.members.filter(isTeammateMember)
+}
+
+export function getTeamMember(config: TeamConfig, name: string): TeamMember | undefined {
+  return config.members.find((member) => member.name === name)
+}
+
+export function upsertTeammate(config: TeamConfig, teammate: TeamTeammateMember): TeamConfig {
+  const members = config.members.filter((member) => member.name !== teammate.name)
+  members.push(teammate)
+  return { ...config, members }
+}
+
+export function removeTeammate(config: TeamConfig, agentName: string): TeamConfig {
+  if (agentName === "team-lead") {
+    throw new Error("cannot_remove_team_lead")
+  }
+
+  return {
+    ...config,
+    members: config.members.filter((member) => member.name !== agentName),
+  }
+}
+
+export function assignNextColor(config: TeamConfig): string {
+  const teammateCount = listTeammates(config).length
+  return TEAM_COLOR_PALETTE[teammateCount % TEAM_COLOR_PALETTE.length]
+}
+
+export function deleteTeamData(teamName: string): void {
+  const teamDir = getTeamDir(teamName)
+  const taskDir = getTeamTaskDir(teamName)
+
+  if (existsSync(teamDir)) {
+    rmSync(teamDir, { recursive: true, force: true })
+  }
+
+  if (existsSync(taskDir)) {
+    rmSync(taskDir, { recursive: true, force: true })
+  }
+}
diff --git a/src/tools/agent-teams/team-lifecycle-tools.ts b/src/tools/agent-teams/team-lifecycle-tools.ts
new file mode 100644
index 000000000..4d281f889
--- /dev/null
+++ b/src/tools/agent-teams/team-lifecycle-tools.ts
@@ -0,0 +1,95 @@
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+import { getTeamConfigPath } from "./paths"
+import { validateTeamName } from "./name-validation"
+import { ensureInbox } from "./inbox-store"
+import {
+  TeamCreateInputSchema,
+  TeamDeleteInputSchema,
+  TeamReadConfigInputSchema,
+  TeamToolContext,
+} from "./types"
+import { createTeamConfig, deleteTeamData, listTeammates, readTeamConfig, readTeamConfigOrThrow } from "./team-config-store"
+
+export function createTeamCreateTool(): ToolDefinition {
+  return tool({
+    description: "Create a team workspace with config, inboxes, and task storage.",
+    args: {
+      team_name: tool.schema.string().describe("Team name (letters, numbers, hyphens, underscores)"),
+      description: tool.schema.string().optional().describe("Team description"),
+    },
+    execute: async (args: Record<string, unknown>, context: TeamToolContext): Promise<string> => {
+      try {
+        const input = TeamCreateInputSchema.parse(args)
+        const nameError = validateTeamName(input.team_name)
+        if (nameError) {
+          return JSON.stringify({ error: nameError })
+        }
+
+        const config = createTeamConfig(
+          input.team_name,
+          input.description ?? "",
+          context.sessionID,
+          process.cwd(),
+          context.agent ?? "native",
+        )
+        ensureInbox(config.name, "team-lead")
+
+        return JSON.stringify({
+          team_name: config.name,
+          team_file_path: getTeamConfigPath(config.name),
+          lead_agent_id: config.leadAgentId,
+        })
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_create_failed" })
+      }
+    },
+  })
+}
+
+export function createTeamDeleteTool(): ToolDefinition {
+  return tool({
+    description: "Delete a team and its stored data. Fails if teammates still exist.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamDeleteInputSchema.parse(args)
+        const config = readTeamConfigOrThrow(input.team_name)
+        const teammates = listTeammates(config)
+        if (teammates.length > 0) {
+          return JSON.stringify({
+            error: "team_has_active_members",
+            members: teammates.map((member) => member.name),
+          })
+        }
+
+        deleteTeamData(input.team_name)
+        return JSON.stringify({ success: true, team_name: input.team_name })
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_delete_failed" })
+      }
+    },
+  })
+}
+
+export function createTeamReadConfigTool(): ToolDefinition {
+  return tool({
+    description: "Read team configuration and member list.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamReadConfigInputSchema.parse(args)
+        const config = readTeamConfig(input.team_name)
+        if (!config) {
+          return JSON.stringify({ error: "team_not_found" })
+        }
+        return JSON.stringify(config)
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_read_config_failed" })
+      }
+    },
+  })
+}
diff --git a/src/tools/agent-teams/team-task-dependency.ts b/src/tools/agent-teams/team-task-dependency.ts
new file mode 100644
index 000000000..0edec7949
--- /dev/null
+++ b/src/tools/agent-teams/team-task-dependency.ts
@@ -0,0 +1,93 @@
+import type { TeamTask, TeamTaskStatus } from "./types"
+
+type PendingEdges = Record<string, Set<string>>
+
+export const TEAM_TASK_STATUS_ORDER: Record<TeamTaskStatus, number> = {
+  pending: 0,
+  in_progress: 1,
+  completed: 2,
+  deleted: 3,
+}
+
+export type TaskReader = (taskId: string) => TeamTask | null
+
+export function wouldCreateCycle(
+  fromTaskId: string,
+  toTaskId: string,
+  pendingEdges: PendingEdges,
+  readTask: TaskReader,
+): boolean {
+  const visited = new Set<string>()
+  const queue: string[] = [toTaskId]
+
+  while (queue.length > 0) {
+    const current = queue.shift()
+    if (!current) {
+      continue
+    }
+
+    if (current === fromTaskId) {
+      return true
+    }
+
+    if (visited.has(current)) {
+      continue
+    }
+    visited.add(current)
+
+    const task = readTask(current)
+    if (task) {
+      for (const dep of task.blockedBy) {
+        if (!visited.has(dep)) {
+          queue.push(dep)
+        }
+      }
+    }
+
+    const pending = pendingEdges[current]
+    if (pending) {
+      for (const dep of pending) {
+        if (!visited.has(dep)) {
+          queue.push(dep)
+        }
+      }
+    }
+  }
+
+  return false
+}
+
+export function ensureForwardStatusTransition(current: TeamTaskStatus, next: TeamTaskStatus): void {
+  const currentOrder = TEAM_TASK_STATUS_ORDER[current]
+  const nextOrder = TEAM_TASK_STATUS_ORDER[next]
+  if (nextOrder < currentOrder) {
+    throw new Error(`invalid_status_transition:${current}->${next}`)
+  }
+}
+
+export function ensureDependenciesCompleted(
+  status: TeamTaskStatus,
+  blockedBy: string[],
+  readTask: TaskReader,
+): void {
+  if (status !== "in_progress" && status !== "completed") {
+    return
+  }
+
+  for (const blockerId of blockedBy) {
+    const blocker = readTask(blockerId)
+    if (blocker && blocker.status !== "completed") {
+      throw new Error(`blocked_by_incomplete:${blockerId}:${blocker.status}`)
+    }
+  }
+}
+
+export function createPendingEdgeMap(): PendingEdges {
+  return {}
+}
+
+export function addPendingEdge(pendingEdges: PendingEdges, from: string, to: string): void {
+  const existing = pendingEdges[from] ?? new Set<string>()
+  existing.add(to)
+  pendingEdges[from] = existing
+}
diff --git a/src/tools/agent-teams/team-task-store.ts b/src/tools/agent-teams/team-task-store.ts
new file mode 100644
index 000000000..abc2d8691
--- /dev/null
+++ b/src/tools/agent-teams/team-task-store.ts
@@ -0,0 +1,127 @@
+import { existsSync, readdirSync, unlinkSync } from "node:fs"
+import { join } from "node:path"
+import {
+  acquireLock,
+  ensureDir,
+  generateTaskId,
+  readJsonSafe,
+  writeJsonAtomic,
+} from "../../features/claude-tasks/storage"
+import { getTeamTaskDir, getTeamTaskPath } from "./paths"
+import { TeamTask, TeamTaskSchema } from "./types"
+
+function withTaskLock<T>(teamName: string, operation: () => T): T {
+  const taskDir = getTeamTaskDir(teamName)
+  ensureDir(taskDir)
+  const lock = acquireLock(taskDir)
+  if (!lock.acquired) {
+    throw new Error("team_task_lock_unavailable")
+  }
+
+  try {
+    return operation()
+  } finally {
+    lock.release()
+  }
+}
+
+export function readTeamTask(teamName: string, taskId: string): TeamTask | null {
+  return readJsonSafe(getTeamTaskPath(teamName, taskId), TeamTaskSchema)
+}
+
+export function readTeamTaskOrThrow(teamName: string, taskId: string): TeamTask {
+  const task = readTeamTask(teamName, taskId)
+  if (!task) {
+    throw new Error("team_task_not_found")
+  }
+  return task
+}
+
+export function listTeamTasks(teamName: string): TeamTask[] {
+  const taskDir = getTeamTaskDir(teamName)
+  if (!existsSync(taskDir)) {
+    return []
+  }
+
+  const files = readdirSync(taskDir)
+    .filter((file) => file.endsWith(".json") && file.startsWith("T-"))
+    .sort((a, b) => a.localeCompare(b))
+
+  const tasks: TeamTask[] = []
+  for (const file of files) {
+    const taskId = file.replace(/\.json$/, "")
+    const task = readTeamTask(teamName, taskId)
+    if (task) {
+      tasks.push(task)
+    }
+  }
+
+  return tasks
+}
+
+export function createTeamTask(
+  teamName: string,
+  subject: string,
+  description: string,
+  activeForm?: string,
+  metadata?: Record<string, unknown>,
+): TeamTask {
+  if (!subject.trim()) {
+    throw new Error("team_task_subject_required")
+  }
+
+  return withTaskLock(teamName, () => {
+    const task: TeamTask = {
+      id: generateTaskId(),
+      subject,
+      description,
+      activeForm,
+      status: "pending",
+      blocks: [],
+      blockedBy: [],
+      ...(metadata ? { metadata } : {}),
+    }
+
+    const validated = TeamTaskSchema.parse(task)
+    writeJsonAtomic(getTeamTaskPath(teamName, validated.id), validated)
+    return validated
+  })
+}
+
+export function writeTeamTask(teamName: string, task: TeamTask): TeamTask {
+  const validated = TeamTaskSchema.parse(task)
+  writeJsonAtomic(getTeamTaskPath(teamName, validated.id), validated)
+  return validated
+}
+
+export function deleteTeamTaskFile(teamName: string, taskId: string): void {
+  const taskPath = getTeamTaskPath(teamName, taskId)
+  if (existsSync(taskPath)) {
+    unlinkSync(taskPath)
+  }
+}
+
+export function readTaskFromDirectory(taskDir: string, taskId: string): TeamTask | null {
+  return readJsonSafe(join(taskDir, `${taskId}.json`), TeamTaskSchema)
+}
+
+export function resetOwnerTasks(teamName: string, ownerName: string): void {
+  withTaskLock(teamName, () => {
+    const tasks = listTeamTasks(teamName)
+    for (const task of tasks) {
+      if (task.owner !== ownerName) {
+        continue
+      }
+      const next: TeamTask = {
+        ...task,
+        owner: undefined,
+        status: task.status === "completed" ? "completed" : "pending",
+      }
+      writeTeamTask(teamName, next)
+    }
+  })
+}
+
+export function withTeamTaskLock<T>(teamName: string, operation: () => T): T {
+  return withTaskLock(teamName, operation)
+}
diff --git a/src/tools/agent-teams/team-task-tools.ts b/src/tools/agent-teams/team-task-tools.ts
new file mode 100644
index 000000000..36a2f0dcf
--- /dev/null
+++ b/src/tools/agent-teams/team-task-tools.ts
@@ -0,0 +1,106 @@
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+import { sendStructuredInboxMessage } from "./inbox-store"
+import { readTeamConfigOrThrow } from "./team-config-store"
+import {
+  TeamTaskCreateInputSchema,
+  TeamTaskGetInputSchema,
+  TeamTaskListInputSchema,
+  TeamTask,
+} from "./types"
+import { createTeamTask, listTeamTasks, readTeamTask } from "./team-task-store"
+
+function buildTaskAssignmentPayload(task: TeamTask): Record<string, unknown> {
+  return {
+    type: "task_assignment",
+    taskId: task.id,
+    subject: task.subject,
+    description: task.description,
+    timestamp: new Date().toISOString(),
+  }
+}
+
+export function createTeamTaskCreateTool(): ToolDefinition {
+  return tool({
+    description: "Create a task in team-scoped storage.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      subject: tool.schema.string().describe("Task subject"),
+      description: tool.schema.string().describe("Task description"),
+      active_form: tool.schema.string().optional().describe("Present-continuous form"),
+      metadata: tool.schema.record(tool.schema.string(), tool.schema.unknown()).optional().describe("Task metadata"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamTaskCreateInputSchema.parse(args)
+        readTeamConfigOrThrow(input.team_name)
+
+        const task = createTeamTask(
+          input.team_name,
+          input.subject,
+          input.description,
+          input.active_form,
+          input.metadata,
+        )
+
+        return JSON.stringify(task)
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_task_create_failed" })
+      }
+    },
+  })
+}
+
+export function createTeamTaskListTool(): ToolDefinition {
+  return tool({
+    description: "List tasks for one team.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamTaskListInputSchema.parse(args)
+        readTeamConfigOrThrow(input.team_name)
+        return JSON.stringify(listTeamTasks(input.team_name))
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_task_list_failed" })
+      }
+    },
+  })
+}
+
+export function createTeamTaskGetTool(): ToolDefinition {
+  return tool({
+    description: "Get one task from team-scoped storage.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      task_id: tool.schema.string().describe("Task id"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamTaskGetInputSchema.parse(args)
+        readTeamConfigOrThrow(input.team_name)
+        const task = readTeamTask(input.team_name, input.task_id)
+        if (!task) {
+          return JSON.stringify({ error: "team_task_not_found" })
+        }
+        return JSON.stringify(task)
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_task_get_failed" })
+      }
+    },
+  })
+}
+
+export function notifyOwnerAssignment(teamName: string, task: TeamTask): void {
+  if (!task.owner || task.status === "deleted") {
+    return
+  }
+
+  sendStructuredInboxMessage(
+    teamName,
+    "team-lead",
+    task.owner,
+    buildTaskAssignmentPayload(task),
+    "task_assignment",
+  )
+}
diff --git a/src/tools/agent-teams/team-task-update-tool.ts b/src/tools/agent-teams/team-task-update-tool.ts
new file mode 100644
index 000000000..95bf3bb94
--- /dev/null
+++ b/src/tools/agent-teams/team-task-update-tool.ts
@@ -0,0 +1,48 @@
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+import { readTeamConfigOrThrow } from "./team-config-store"
+import { TeamTaskUpdateInputSchema } from "./types"
+import { updateTeamTask } from "./team-task-update"
+import { notifyOwnerAssignment } from "./team-task-tools"
+
+export function createTeamTaskUpdateTool(): ToolDefinition {
+  return tool({
+    description: "Update task status, owner, dependencies, and metadata in a team task list.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      task_id: tool.schema.string().describe("Task id"),
+      status: tool.schema.enum(["pending", "in_progress", "completed", "deleted"]).optional().describe("Task status"),
+      owner: tool.schema.string().optional().describe("Task owner"),
+      subject: tool.schema.string().optional().describe("Task subject"),
+      description: tool.schema.string().optional().describe("Task description"),
+      active_form: tool.schema.string().optional().describe("Present-continuous form"),
+      add_blocks: tool.schema.array(tool.schema.string()).optional().describe("Add task ids this task blocks"),
+      add_blocked_by: tool.schema.array(tool.schema.string()).optional().describe("Add blocker task ids"),
+      metadata: tool.schema.record(tool.schema.string(), tool.schema.unknown()).optional().describe("Metadata patch (null removes key)"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamTaskUpdateInputSchema.parse(args)
+        readTeamConfigOrThrow(input.team_name)
+
+        const task = updateTeamTask(input.team_name, input.task_id, {
+          status: input.status,
+          owner: input.owner,
+          subject: input.subject,
+          description: input.description,
+          activeForm: input.active_form,
+          addBlocks: input.add_blocks,
+          addBlockedBy: input.add_blocked_by,
+          metadata: input.metadata,
+        })
+
+        if (input.owner !== undefined) {
+          notifyOwnerAssignment(input.team_name, task)
+        }
+
+        return JSON.stringify(task)
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "team_task_update_failed" })
+      }
+    },
+  })
+}
diff --git a/src/tools/agent-teams/team-task-update.ts b/src/tools/agent-teams/team-task-update.ts
new file mode 100644
index 000000000..d7171ee73
--- /dev/null
+++ b/src/tools/agent-teams/team-task-update.ts
@@ -0,0 +1,210 @@
+import { existsSync, readdirSync, unlinkSync } from "node:fs"
+import { join } from "node:path"
+import { readJsonSafe, writeJsonAtomic } from "../../features/claude-tasks/storage"
+import { getTeamTaskDir, getTeamTaskPath } from "./paths"
+import {
+  addPendingEdge,
+  createPendingEdgeMap,
+  ensureDependenciesCompleted,
+  ensureForwardStatusTransition,
+  wouldCreateCycle,
+} from "./team-task-dependency"
+import { TeamTask, TeamTaskSchema, TeamTaskStatus } from "./types"
+import { withTeamTaskLock } from "./team-task-store"
+
+export interface TeamTaskUpdatePatch {
+  status?: TeamTaskStatus
+  owner?: string
+  subject?: string
+  description?: string
+  activeForm?: string
+  addBlocks?: string[]
+  addBlockedBy?: string[]
+  metadata?: Record<string, unknown>
+}
+
+function writeTaskToPath(path: string, task: TeamTask): void {
+  writeJsonAtomic(path, TeamTaskSchema.parse(task))
+}
+
+export function updateTeamTask(teamName: string, taskId: string, patch: TeamTaskUpdatePatch): TeamTask {
+  return withTeamTaskLock(teamName, () => {
+    const taskDir = getTeamTaskDir(teamName)
+    const taskPath = getTeamTaskPath(teamName, taskId)
+    const currentTask = readJsonSafe(taskPath, TeamTaskSchema)
+    if (!currentTask) {
+      throw new Error("team_task_not_found")
+    }
+
+    const cache = new Map<string, TeamTask | null>()
+    cache.set(taskId, currentTask)
+
+    const readTask = (id: string): TeamTask | null => {
+      if (cache.has(id)) {
+        return cache.get(id) ?? null
+      }
+      const loaded = readJsonSafe(join(taskDir, `${id}.json`), TeamTaskSchema)
+      cache.set(id, loaded)
+      return loaded
+    }
+
+    const pendingEdges = createPendingEdgeMap()
+
+    if (patch.addBlocks) {
+      for (const blockedTaskId of patch.addBlocks) {
+        if (blockedTaskId === taskId) {
+          throw new Error("team_task_self_block")
+        }
+        if (!readTask(blockedTaskId)) {
+          throw new Error(`team_task_reference_not_found:${blockedTaskId}`)
+        }
+        addPendingEdge(pendingEdges, blockedTaskId, taskId)
+      }
+
+      for (const blockedTaskId of patch.addBlocks) {
+        if (wouldCreateCycle(blockedTaskId, taskId, pendingEdges, readTask)) {
+          throw new Error(`team_task_cycle_detected:${taskId}->${blockedTaskId}`)
+        }
+      }
+    }
+
+    if (patch.addBlockedBy) {
+      for (const blockerId of patch.addBlockedBy) {
+        if (blockerId === taskId) {
+          throw new Error("team_task_self_dependency")
+        }
+        if (!readTask(blockerId)) {
+          throw new Error(`team_task_reference_not_found:${blockerId}`)
+        }
+        addPendingEdge(pendingEdges, taskId, blockerId)
+      }
+
+      for (const blockerId of patch.addBlockedBy) {
+        if (wouldCreateCycle(taskId, blockerId, pendingEdges, readTask)) {
+          throw new Error(`team_task_cycle_detected:${taskId}<-${blockerId}`)
+        }
+      }
+    }
+
+    if (patch.status && patch.status !== "deleted") {
+      ensureForwardStatusTransition(currentTask.status, patch.status)
+      const effectiveBlockedBy = Array.from(new Set([...(currentTask.blockedBy ?? []), ...(patch.addBlockedBy ?? [])]))
+      ensureDependenciesCompleted(patch.status, effectiveBlockedBy, readTask)
+    }
+
+    let nextTask: TeamTask = { ...currentTask }
+
+    if (patch.subject !== undefined) {
+      nextTask.subject = patch.subject
+    }
+    if (patch.description !== undefined) {
+      nextTask.description = patch.description
+    }
+    if (patch.activeForm !== undefined) {
+      nextTask.activeForm = patch.activeForm
+    }
+    if (patch.owner !== undefined) {
+      nextTask.owner = patch.owner
+    }
+
+    const pendingWrites = new Map<string, TeamTask>()
+
+    if (patch.addBlocks) {
+      const existingBlocks = new Set(nextTask.blocks)
+      for (const blockedTaskId of patch.addBlocks) {
+        if (!existingBlocks.has(blockedTaskId)) {
+          nextTask.blocks.push(blockedTaskId)
+          existingBlocks.add(blockedTaskId)
+        }
+
+        const otherPath = getTeamTaskPath(teamName, blockedTaskId)
+        const other = pendingWrites.get(otherPath) ?? readTask(blockedTaskId)
+        if (other && !other.blockedBy.includes(taskId)) {
+          pendingWrites.set(otherPath, { ...other, blockedBy: [...other.blockedBy, taskId] })
+        }
+      }
+    }
+
+    if (patch.addBlockedBy) {
+      const existingBlockedBy = new Set(nextTask.blockedBy)
+      for (const blockerId of patch.addBlockedBy) {
+        if (!existingBlockedBy.has(blockerId)) {
+          nextTask.blockedBy.push(blockerId)
+          existingBlockedBy.add(blockerId)
+        }
+
+        const otherPath = getTeamTaskPath(teamName, blockerId)
+        const other = pendingWrites.get(otherPath) ?? readTask(blockerId)
+        if (other && !other.blocks.includes(taskId)) {
+          pendingWrites.set(otherPath, { ...other, blocks: [...other.blocks, taskId] })
+        }
+      }
+    }
+
+    if (patch.metadata !== undefined) {
+      const merged: Record<string, unknown> = { ...(nextTask.metadata ?? {}) }
+      for (const [key, value] of Object.entries(patch.metadata)) {
+        if (value === null) {
+          delete merged[key]
+        } else {
+          merged[key] = value
+        }
+      }
+      nextTask.metadata = Object.keys(merged).length > 0 ? merged : undefined
+    }
+
+    if (patch.status !== undefined) {
+      nextTask.status = patch.status
+    }
+
+    const allTaskFiles = readdirSync(taskDir).filter((file) => file.endsWith(".json") && file.startsWith("T-"))
+
+    if (nextTask.status === "completed") {
+      for (const file of allTaskFiles) {
+        const otherId = file.replace(/\.json$/, "")
+        if (otherId === taskId) continue
+
+        const otherPath = getTeamTaskPath(teamName, otherId)
+        const other = pendingWrites.get(otherPath) ?? readTask(otherId)
+        if (other?.blockedBy.includes(taskId)) {
+          pendingWrites.set(otherPath, {
+            ...other,
+            blockedBy: other.blockedBy.filter((id) => id !== taskId),
+          })
+        }
+      }
+    }
+
+    if (patch.status === "deleted") {
+      for (const file of allTaskFiles) {
+        const otherId = file.replace(/\.json$/, "")
+        if (otherId === taskId) continue
+
+        const otherPath = getTeamTaskPath(teamName, otherId)
+        const other = pendingWrites.get(otherPath) ?? readTask(otherId)
+        if (!other) continue
+
+        const nextOther = {
+          ...other,
+          blockedBy: other.blockedBy.filter((id) => id !== taskId),
+          blocks: other.blocks.filter((id) => id !== taskId),
+        }
+        pendingWrites.set(otherPath, nextOther)
+      }
+    }
+
+    for (const [path, task] of pendingWrites.entries()) {
+      writeTaskToPath(path, task)
+    }
+
+    if (patch.status === "deleted") {
+      if (existsSync(taskPath)) {
+        unlinkSync(taskPath)
+      }
+      return TeamTaskSchema.parse({ ...nextTask, status: "deleted" })
+    }
+
+    writeTaskToPath(taskPath, nextTask)
+    return TeamTaskSchema.parse(nextTask)
+  })
+}
diff --git a/src/tools/agent-teams/teammate-runtime.ts b/src/tools/agent-teams/teammate-runtime.ts
new file mode 100644
index 000000000..052a58c60
--- /dev/null
+++ b/src/tools/agent-teams/teammate-runtime.ts
@@ -0,0 +1,148 @@
+import type { BackgroundManager } from "../../features/background-agent"
+import { ensureInbox, sendPlainInboxMessage } from "./inbox-store"
+import { assignNextColor, getTeamMember, readTeamConfigOrThrow, removeTeammate, upsertTeammate, writeTeamConfig } from "./team-config-store"
+import type { TeamTeammateMember, TeamToolContext } from "./types"
+
+function parseModel(model: string | undefined): { providerID: string; modelID: string } | undefined {
+  if (!model) {
+    return undefined
+  }
+  const [providerID, modelID] = model.split("/", 2)
+  if (!providerID || !modelID) {
+    return undefined
+  }
+  return { providerID, modelID }
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms))
+}
+
+function buildLaunchPrompt(teamName: string, teammateName: string, userPrompt: string): string {
+  return [
+    `You are teammate "${teammateName}" in team "${teamName}".`,
+    `When you need updates, call read_inbox with team_name="${teamName}" and agent_name="${teammateName}".`,
+    "Initial assignment:",
+    userPrompt,
+  ].join("\n\n")
+}
+
+function buildDeliveryPrompt(teamName: string, teammateName: string, summary: string, content: string): string {
+  return [
+    `New team message for "${teammateName}" in team "${teamName}".`,
+    `Summary: ${summary}`,
+    "Content:",
+    content,
+  ].join("\n\n")
+}
+
+export interface SpawnTeammateParams {
+  teamName: string
+  name: string
+  prompt: string
+  subagentType: string
+  model?: string
+  planModeRequired: boolean
+  context: TeamToolContext
+  manager: BackgroundManager
+}
+
+export async function spawnTeammate(params: SpawnTeammateParams): Promise<TeamTeammateMember> {
+  const config = readTeamConfigOrThrow(params.teamName)
+
+  if (getTeamMember(config, params.name)) {
+    throw new Error("teammate_already_exists")
+  }
+
+  const teammate: TeamTeammateMember = {
+    agentId: `${params.name}@${params.teamName}`,
+    name: params.name,
+    agentType: params.subagentType,
+    model: params.model ?? "native",
+    prompt: params.prompt,
+    color: assignNextColor(config),
+    planModeRequired: params.planModeRequired,
+    joinedAt: Date.now(),
+    cwd: process.cwd(),
+    subscriptions: [],
+    backendType: "native",
+    isActive: false,
+  }
+
+  writeTeamConfig(params.teamName, upsertTeammate(config, teammate))
+  ensureInbox(params.teamName, params.name)
+  sendPlainInboxMessage(params.teamName, "team-lead", params.name, params.prompt, "initial_prompt", teammate.color)
+
+  try {
+    const resolvedModel = parseModel(params.model)
+    const launched = await params.manager.launch({
+      description: `[team:${params.teamName}] ${params.name}`,
+      prompt: buildLaunchPrompt(params.teamName, params.name, params.prompt),
+      agent: params.subagentType,
+      parentSessionID: params.context.sessionID,
+      parentMessageID: params.context.messageID,
+      ...(resolvedModel ? { model: resolvedModel } : {}),
+      parentAgent: params.context.agent,
+    })
+
+    const start = Date.now()
+    let sessionID = launched.sessionID
+    while (!sessionID && Date.now() - start < 30_000) {
+      await delay(50)
+      const task = params.manager.getTask(launched.id)
+      sessionID = task?.sessionID
+    }
+
+    const nextMember: TeamTeammateMember = {
+      ...teammate,
+      isActive: true,
+      backgroundTaskID: launched.id,
+      ...(sessionID ? { sessionID } : {}),
+    }
+
+    const current = readTeamConfigOrThrow(params.teamName)
+    writeTeamConfig(params.teamName, upsertTeammate(current, nextMember))
+    return nextMember
+  } catch (error) {
+    const rollback = readTeamConfigOrThrow(params.teamName)
+    writeTeamConfig(params.teamName, removeTeammate(rollback, params.name))
+    throw error
+  }
+}
+
+export async function resumeTeammateWithMessage(
+  manager: BackgroundManager,
+  context: TeamToolContext,
+  teamName: string,
+  teammate: TeamTeammateMember,
+  summary: string,
+  content: string,
+): Promise<void> {
+  if (!teammate.sessionID) {
+    return
+  }
+
+  try {
+    await manager.resume({
+      sessionId: teammate.sessionID,
+      prompt: buildDeliveryPrompt(teamName, teammate.name, summary, content),
+      parentSessionID: context.sessionID,
+      parentMessageID: context.messageID,
+      parentAgent: context.agent,
+    })
+  } catch {
+    return
+  }
+}
+
+export async function cancelTeammateRun(manager: BackgroundManager, teammate: TeamTeammateMember): Promise<void> {
+  if (!teammate.backgroundTaskID) {
+    return
+  }
+
+  await manager.cancelTask(teammate.backgroundTaskID, {
+    source: "team_force_kill",
+    abortSession: true,
+    skipNotification: true,
+  })
+}
diff --git a/src/tools/agent-teams/teammate-tools.ts b/src/tools/agent-teams/teammate-tools.ts
new file mode 100644
index 000000000..062be0256
--- /dev/null
+++ b/src/tools/agent-teams/teammate-tools.ts
@@ -0,0 +1,121 @@
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+import type { BackgroundManager } from "../../features/background-agent"
+import { validateAgentName, validateTeamName } from "./name-validation"
+import {
+  TeamForceKillInputSchema,
+  TeamProcessShutdownInputSchema,
+  TeamSpawnInputSchema,
+  TeamToolContext,
+  isTeammateMember,
+} from "./types"
+import { getTeamMember, readTeamConfigOrThrow, removeTeammate, writeTeamConfig } from "./team-config-store"
+import { cancelTeammateRun, spawnTeammate } from "./teammate-runtime"
+import { resetOwnerTasks } from "./team-task-store"
+
+export function createSpawnTeammateTool(manager: BackgroundManager): ToolDefinition {
+  return tool({
+    description: "Spawn a teammate using native internal agent execution.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      name: tool.schema.string().describe("Teammate name"),
+      prompt: tool.schema.string().describe("Initial teammate prompt"),
+      subagent_type: tool.schema.string().optional().describe("Agent name to run (default: sisyphus-junior)"),
+      model: tool.schema.string().optional().describe("Optional model override in provider/model format"),
+      plan_mode_required: tool.schema.boolean().optional().describe("Enable plan mode flag in teammate metadata"),
+    },
+    execute: async (args: Record<string, unknown>, context: TeamToolContext): Promise<string> => {
+      try {
+        const input = TeamSpawnInputSchema.parse(args)
+        const teamError = validateTeamName(input.team_name)
+        if (teamError) {
+          return JSON.stringify({ error: teamError })
+        }
+
+        const agentError = validateAgentName(input.name)
+        if (agentError) {
+          return JSON.stringify({ error: agentError })
+        }
+
+        const teammate = await spawnTeammate({
+          teamName: input.team_name,
+          name: input.name,
+          prompt: input.prompt,
+          subagentType: input.subagent_type ?? "sisyphus-junior",
+          model: input.model,
+          planModeRequired: input.plan_mode_required ?? false,
+          context,
+          manager,
+        })
+
+        return JSON.stringify({
+          agent_id: teammate.agentId,
+          name: teammate.name,
+          team_name: input.team_name,
+          session_id: teammate.sessionID,
+          task_id: teammate.backgroundTaskID,
+        })
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "spawn_teammate_failed" })
+      }
+    },
+  })
+}
+
+export function createForceKillTeammateTool(manager: BackgroundManager): ToolDefinition {
+  return tool({
+    description: "Force stop a teammate and clean up ownership state.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      agent_name: tool.schema.string().describe("Teammate name"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamForceKillInputSchema.parse(args)
+        const config = readTeamConfigOrThrow(input.team_name)
+        const member = getTeamMember(config, input.agent_name)
+        if (!member || !isTeammateMember(member)) {
+          return JSON.stringify({ error: "teammate_not_found" })
+        }
+
+        await cancelTeammateRun(manager, member)
+        writeTeamConfig(input.team_name, removeTeammate(config, input.agent_name))
+        resetOwnerTasks(input.team_name, input.agent_name)
+
+        return JSON.stringify({ success: true, message: `${input.agent_name} stopped` })
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "force_kill_teammate_failed" })
+      }
+    },
+  })
+}
+
+export function createProcessShutdownTool(): ToolDefinition {
+  return tool({
+    description: "Finalize an approved shutdown by removing teammate and resetting owned tasks.",
+    args: {
+      team_name: tool.schema.string().describe("Team name"),
+      agent_name: tool.schema.string().describe("Teammate name"),
+    },
+    execute: async (args: Record<string, unknown>): Promise<string> => {
+      try {
+        const input = TeamProcessShutdownInputSchema.parse(args)
+        if (input.agent_name === "team-lead") {
+          return JSON.stringify({ error: "cannot_shutdown_team_lead" })
+        }
+
+        const config = readTeamConfigOrThrow(input.team_name)
+        const member = getTeamMember(config, input.agent_name)
+        if (!member || !isTeammateMember(member)) {
+          return JSON.stringify({ error: "teammate_not_found" })
+        }
+
+        writeTeamConfig(input.team_name, removeTeammate(config, input.agent_name))
+        resetOwnerTasks(input.team_name, input.agent_name)
+
+        return JSON.stringify({ success: true, message: `${input.agent_name} removed` })
+      } catch (error) {
+        return JSON.stringify({ error: error instanceof Error ? error.message : "process_shutdown_failed" })
+      }
+    },
+  })
+}
diff --git a/src/tools/agent-teams/tools.ts b/src/tools/agent-teams/tools.ts
new file mode 100644
index 000000000..dd4a26e44
--- /dev/null
+++ b/src/tools/agent-teams/tools.ts
@@ -0,0 +1,24 @@
+import type { ToolDefinition } from "@opencode-ai/plugin"
+import type { BackgroundManager } from "../../features/background-agent"
+import { createReadInboxTool, createSendMessageTool } from "./messaging-tools"
+import { createTeamCreateTool, createTeamDeleteTool, createTeamReadConfigTool } from "./team-lifecycle-tools"
+import { createTeamTaskCreateTool, createTeamTaskGetTool, createTeamTaskListTool } from "./team-task-tools"
+import { createTeamTaskUpdateTool } from "./team-task-update-tool"
+import { createForceKillTeammateTool, createProcessShutdownTool, createSpawnTeammateTool } from "./teammate-tools"
+
+export function createAgentTeamsTools(manager: BackgroundManager): Record<string, ToolDefinition> {
+  return {
+    team_create: createTeamCreateTool(),
+    team_delete: createTeamDeleteTool(),
+    spawn_teammate: createSpawnTeammateTool(manager),
+    send_message: createSendMessageTool(manager),
+    read_inbox: createReadInboxTool(),
+    read_config: createTeamReadConfigTool(),
+    team_task_create: createTeamTaskCreateTool(),
+    team_task_update: createTeamTaskUpdateTool(),
+    team_task_list: createTeamTaskListTool(),
+    team_task_get: createTeamTaskGetTool(),
+    force_kill_teammate: createForceKillTeammateTool(manager),
+    process_shutdown_approved: createProcessShutdownTool(),
+  }
+}
diff --git a/src/tools/agent-teams/types.ts b/src/tools/agent-teams/types.ts
new file mode 100644
index 000000000..cfa76d76f
--- /dev/null
+++ b/src/tools/agent-teams/types.ts
@@ -0,0 +1,180 @@
+import { z } from "zod"
+
+export const TEAM_COLOR_PALETTE = [
+  "blue",
+  "green",
+  "yellow",
+  "purple",
+  "orange",
+  "pink",
+  "cyan",
+  "red",
+] as const
+
+export const TeamTaskStatusSchema = z.enum(["pending", "in_progress", "completed", "deleted"])
+export type TeamTaskStatus = z.infer<typeof TeamTaskStatusSchema>
+
+export const TeamLeadMemberSchema = z.object({
+  agentId: z.string(),
+  name: z.literal("team-lead"),
+  agentType: z.literal("team-lead"),
+  model: z.string(),
+  joinedAt: z.number(),
+  cwd: z.string(),
+  subscriptions: z.array(z.unknown()).default([]),
+}).strict()
+
+export const TeamTeammateMemberSchema = z.object({
+  agentId: z.string(),
+  name: z.string(),
+  agentType: z.string(),
+  model: z.string(),
+  prompt: z.string(),
+  color: z.string(),
+  planModeRequired: z.boolean().default(false),
+  joinedAt: z.number(),
+  cwd: z.string(),
+  subscriptions: z.array(z.unknown()).default([]),
+  backendType: z.literal("native").default("native"),
+  isActive: z.boolean().default(false),
+  sessionID: z.string().optional(),
+  backgroundTaskID: z.string().optional(),
+}).strict()
+
+export const TeamMemberSchema = z.union([TeamLeadMemberSchema, TeamTeammateMemberSchema])
+
+export const TeamConfigSchema = z.object({
+  name: z.string(),
+  description: z.string().default(""),
+  createdAt: z.number(),
+  leadAgentId: z.string(),
+  leadSessionId: z.string(),
+  members: z.array(TeamMemberSchema),
+}).strict()
+
+export const TeamInboxMessageSchema = z.object({
+  from: z.string(),
+  text: z.string(),
+  timestamp: z.string(),
+  read: z.boolean().default(false),
+  summary: z.string().optional(),
+  color: z.string().optional(),
+}).strict()
+
+export const TeamTaskSchema = z.object({
+  id: z.string(),
+  subject: z.string(),
+  description: z.string(),
+  activeForm: z.string().optional(),
+  status: TeamTaskStatusSchema,
+  blocks: z.array(z.string()).default([]),
+  blockedBy: z.array(z.string()).default([]),
+  owner: z.string().optional(),
+  metadata: z.record(z.string(), z.unknown()).optional(),
+}).strict()
+
+export const TeamSendMessageTypeSchema = z.enum([
+  "message",
+  "broadcast",
+  "shutdown_request",
+  "shutdown_response",
+  "plan_approval_response",
+])
+
+export type TeamLeadMember = z.infer<typeof TeamLeadMemberSchema>
+export type TeamTeammateMember = z.infer<typeof TeamTeammateMemberSchema>
+export type TeamMember = z.infer<typeof TeamMemberSchema>
+export type TeamConfig = z.infer<typeof TeamConfigSchema>
+export type TeamInboxMessage = z.infer<typeof TeamInboxMessageSchema>
+export type TeamTask = z.infer<typeof TeamTaskSchema>
+export type TeamSendMessageType = z.infer<typeof TeamSendMessageTypeSchema>
+
+export const TeamCreateInputSchema = z.object({
+  team_name: z.string(),
+  description: z.string().optional(),
+})
+
+export const TeamDeleteInputSchema = z.object({
+  team_name: z.string(),
+})
+
+export const TeamReadConfigInputSchema = z.object({
+  team_name: z.string(),
+})
+
+export const TeamSpawnInputSchema = z.object({
+  team_name: z.string(),
+  name: z.string(),
+  prompt: z.string(),
+  subagent_type: z.string().optional(),
+  model: z.string().optional(),
+  plan_mode_required: z.boolean().optional(),
+})
+
+export const TeamSendMessageInputSchema = z.object({
+  team_name: z.string(),
+  type: TeamSendMessageTypeSchema,
+  recipient: z.string().optional(),
+  content: z.string().optional(),
+  summary: z.string().optional(),
+  request_id: z.string().optional(),
+  approve: z.boolean().optional(),
+  sender: z.string().optional(),
+})
+
+export const TeamReadInboxInputSchema = z.object({
+  team_name: z.string(),
+  agent_name: z.string(),
+  unread_only: z.boolean().optional(),
+  mark_as_read: z.boolean().optional(),
+})
+
+export const TeamTaskCreateInputSchema = z.object({
+  team_name: z.string(),
+  subject: z.string(),
+  description: z.string(),
+  active_form: z.string().optional(),
+  metadata: z.record(z.string(), z.unknown()).optional(),
+})
+
+export const TeamTaskUpdateInputSchema = z.object({
+  team_name: z.string(),
+  task_id: z.string(),
+  status: TeamTaskStatusSchema.optional(),
+  owner: z.string().optional(),
+  subject: z.string().optional(),
+  description: z.string().optional(),
+  active_form: z.string().optional(),
+  add_blocks: z.array(z.string()).optional(),
+  add_blocked_by: z.array(z.string()).optional(),
+  metadata: z.record(z.string(), z.unknown()).optional(),
+})
+
+export const TeamTaskListInputSchema = z.object({
+  team_name: z.string(),
+})
+
+export const TeamTaskGetInputSchema = z.object({
+  team_name: z.string(),
+  task_id: z.string(),
+})
+
+export const TeamForceKillInputSchema = z.object({
+  team_name: z.string(),
+  agent_name: z.string(),
+})
+
+export const TeamProcessShutdownInputSchema = z.object({
+  team_name: z.string(),
+  agent_name: z.string(),
+})
+
+export interface TeamToolContext {
+  sessionID: string
+  messageID: string
+  agent?: string
+}
+
+export function isTeammateMember(member: TeamMember): member is TeamTeammateMember {
+  return member.agentType !== "team-lead"
+}
diff --git a/src/tools/index.ts b/src/tools/index.ts
index a38a6c74c..9287d9568 100644
--- a/src/tools/index.ts
+++ b/src/tools/index.ts
@@ -37,6 +37,7 @@ type OpencodeClient = PluginInput["client"]
 export { createCallOmoAgent } from "./call-omo-agent"
 export { createLookAt } from "./look-at"
 export { createDelegateTask } from "./delegate-task"
+export { createAgentTeamsTools } from "./agent-teams"
 export {
   createTaskCreateTool,
   createTaskGetTool,