diff --git a/src/tools/builtin/process/index.ts b/src/tools/builtin/process/index.ts
new file mode 100644
index 0000000..cad7f8c
--- /dev/null
+++ b/src/tools/builtin/process/index.ts
@@ -0,0 +1,26 @@
+export { ProcessManager, RingBuffer } from './manager.js';
+export type { ManagedProcess, ProcessManagerConfig } from './manager.js';
+export { createProcessStartTool } from './start.js';
+export { createProcessStatusTool } from './status.js';
+export { createProcessOutputTool } from './output.js';
+export { createProcessKillTool } from './kill.js';
+export { createProcessListTool } from './list.js';
+
+import type { Tool } from '../../types.js';
+import type { ProcessManager } from './manager.js';
+import { createProcessStartTool } from './start.js';
+import { createProcessStatusTool } from './status.js';
+import { createProcessOutputTool } from './output.js';
+import { createProcessKillTool } from './kill.js';
+import { createProcessListTool } from './list.js';
+
+/** Create all process management tools bound to a ProcessManager instance. */
+export function createProcessTools(manager: ProcessManager): Tool[] {
+  return [
+    createProcessStartTool(manager),
+    createProcessStatusTool(manager),
+    createProcessOutputTool(manager),
+    createProcessKillTool(manager),
+    createProcessListTool(manager),
+  ];
+}
diff --git a/src/tools/builtin/process/kill.ts b/src/tools/builtin/process/kill.ts
new file mode 100644
index 0000000..a99cff3
--- /dev/null
+++ b/src/tools/builtin/process/kill.ts
@@ -0,0 +1,44 @@
+import type { Tool, ToolResult } from '../../types.js';
+import type { ProcessManager } from './manager.js';
+
+interface ProcessKillArgs {
+  id: string;
+  signal?: string;
+}
+
+export function createProcessKillTool(manager: ProcessManager): Tool {
+  return {
+    name: 'process.kill',
+    description: 'Kill a background process by its ID.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        id: { type: 'string', description: 'Process ID (e.g. "proc_1")' },
+        signal: { type: 'string', description: 'Signal to send (default: SIGTERM). Use SIGKILL for force kill.' },
+      },
+      required: ['id'],
+    },
+    execute: async (rawArgs: unknown): Promise<ToolResult> => {
+      const args = rawArgs as ProcessKillArgs;
+      try {
+        const signal = (args.signal ?? 'SIGTERM') as NodeJS.Signals;
+        const killed = manager.kill(args.id, signal);
+        if (killed) {
+          return { success: true, output: `Sent ${signal} to process ${args.id}` };
+        }
+        const proc = manager.get(args.id);
+        return {
+          success: false,
+          output: '',
+          error: `Process ${args.id} is not running (status: ${proc?.status ?? 'unknown'})`,
+        };
+      } catch (error) {
+        return {
+          success: false,
+          output: '',
+          error: error instanceof Error ? error.message : 'Failed to kill process',
+        };
+      }
+    },
+  };
+}
diff --git a/src/tools/builtin/process/list.ts b/src/tools/builtin/process/list.ts
new file mode 100644
index 0000000..d6d2258
--- /dev/null
+++ b/src/tools/builtin/process/list.ts
@@ -0,0 +1,31 @@
+import type { Tool, ToolResult } from '../../types.js';
+import type { ProcessManager } from './manager.js';
+
+export function createProcessListTool(manager: ProcessManager): Tool {
+  return {
+    name: 'process.list',
+    description: 'List all managed background processes and their current status.',
+    inputSchema: {
+      type: 'object',
+      properties: {},
+      required: [],
+    },
+    execute: async (): Promise<ToolResult> => {
+      const procs = manager.list();
+      if (procs.length === 0) {
+        return { success: true, output: 'No managed processes.' };
+      }
+
+      const lines = procs.map(p => {
+        const uptime = p.status === 'running'
+          ? `${Math.round((Date.now() - p.startedAt) / 1000)}s`
+          : 'N/A';
+        let line = `${p.id}  PID=${p.pid}  status=${p.status}  uptime=${uptime}  cmd="${p.command}"`;
+        if (p.exitCode !== undefined) line += `  exit=${p.exitCode}`;
+        return line;
+      });
+
+      return { success: true, output: lines.join('\n') };
+    },
+  };
+}
diff --git a/src/tools/builtin/process/manager.test.ts b/src/tools/builtin/process/manager.test.ts
new file mode 100644
index 0000000..51c55ef
--- /dev/null
+++ b/src/tools/builtin/process/manager.test.ts
@@ -0,0 +1,306 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { RingBuffer, ProcessManager } from './manager.js';
+
+describe('RingBuffer', () => {
+  it('reads empty buffer as empty string', () => {
+    const buf = new RingBuffer(16);
+    expect(buf.read()).toBe('');
+    expect(buf.size).toBe(0);
+  });
+
+  it('writes and reads data smaller than capacity', () => {
+    const buf = new RingBuffer(64);
+    buf.write('hello');
+    expect(buf.read()).toBe('hello');
+    expect(buf.size).toBe(5);
+  });
+
+  it('accumulates multiple writes', () => {
+    const buf = new RingBuffer(64);
+    buf.write('hello ');
+    buf.write('world');
+    expect(buf.read()).toBe('hello world');
+    expect(buf.size).toBe(11);
+  });
+
+  it('wraps around when full, keeping newest data', () => {
+    const buf = new RingBuffer(8);
+    buf.write('ABCDEFGH'); // fills exactly
+    expect(buf.read()).toBe('ABCDEFGH');
+
+    buf.write('IJ'); // overwrites A and B
+    expect(buf.read()).toBe('CDEFGHIJ');
+  });
+
+  it('handles data larger than capacity', () => {
+    const buf = new RingBuffer(4);
+    buf.write('ABCDEFGH'); // only last 4 bytes kept
+    expect(buf.read()).toBe('EFGH');
+    expect(buf.size).toBe(4);
+  });
+
+  it('handles exact capacity writes', () => {
+    const buf = new RingBuffer(5);
+    buf.write('ABCDE');
+    expect(buf.read()).toBe('ABCDE');
+  });
+
+  it('clears the buffer', () => {
+    const buf = new RingBuffer(16);
+    buf.write('data');
+    buf.clear();
+    expect(buf.read()).toBe('');
+    expect(buf.size).toBe(0);
+  });
+
+  it('handles Buffer input', () => {
+    const buf = new RingBuffer(64);
+    buf.write(Buffer.from('bytes'));
+    expect(buf.read()).toBe('bytes');
+  });
+
+  it('handles multiple wraps correctly', () => {
+    const buf = new RingBuffer(8);
+    // Write 6 bytes
+    buf.write('ABCDEF');
+    expect(buf.read()).toBe('ABCDEF');
+    // Write 6 more (wraps past end)
+    buf.write('GHIJKL');
+    // Should have the last 8 bytes: EFGHIJKL
+    expect(buf.read()).toBe('EFGHIJKL');
+  });
+});
+
+describe('ProcessManager', () => {
+  const managers: ProcessManager[] = [];
+
+  function createManager(config?: { maxConcurrent?: number; maxRuntimeMinutes?: number; bufferSize?: number }) {
+    const m = new ProcessManager(config);
+    managers.push(m);
+    return m;
+  }
+
+  afterEach(async () => {
+    for (const m of managers) {
+      await m.shutdown();
+    }
+    managers.length = 0;
+  });
+
+  it('starts a process and captures output', async () => {
+    const manager = createManager();
+    const proc = manager.start('echo "hello background"');
+    expect(proc.id).toBe('proc_1');
+    expect(proc.status).toBe('running');
+    expect(proc.pid).toBeGreaterThan(0);
+
+    // Wait for process to finish
+    await new Promise(resolve => setTimeout(resolve, 500));
+
+    expect(proc.status).toBe('exited');
+    expect(proc.exitCode).toBe(0);
+
+    const output = manager.getOutput(proc.id);
+    expect(output).toContain('hello background');
+  });
+
+  it('tracks multiple processes', async () => {
+    const manager = createManager();
+    const p1 = manager.start('echo one');
+    const p2 = manager.start('echo two');
+    expect(p1.id).toBe('proc_1');
+    expect(p2.id).toBe('proc_2');
+    expect(manager.list()).toHaveLength(2);
+
+    await new Promise(resolve => setTimeout(resolve, 500));
+
+    expect(manager.getOutput(p1.id)).toContain('one');
+    expect(manager.getOutput(p2.id)).toContain('two');
+  });
+
+  it('kills a running process', async () => {
+    const manager = createManager();
+    const proc = manager.start('sleep 60');
+    expect(proc.status).toBe('running');
+    expect(manager.runningCount()).toBe(1);
+
+    const killed = manager.kill(proc.id);
+    expect(killed).toBe(true);
+
+    // Wait for exit event
+    await new Promise(resolve => setTimeout(resolve, 300));
+    expect(proc.status).toBe('killed');
+    expect(manager.runningCount()).toBe(0);
+  });
+
+  it('enforces max concurrent limit', () => {
+    const manager = createManager({ maxConcurrent: 2 });
+    manager.start('sleep 60');
+    manager.start('sleep 60');
+
+    expect(() => manager.start('sleep 60')).toThrow('Maximum concurrent processes (2) reached');
+  });
+
+  it('returns undefined for unknown process ID', () => {
+    const manager = createManager();
+    expect(manager.get('proc_999')).toBeUndefined();
+  });
+
+  it('throws when getting output of unknown process', () => {
+    const manager = createManager();
+    expect(() => manager.getOutput('proc_999')).toThrow('Process proc_999 not found');
+  });
+
+  it('throws when killing unknown process', () => {
+    const manager = createManager();
+    expect(() => manager.kill('proc_999')).toThrow('Process proc_999 not found');
+  });
+
+  it('returns false when killing a non-running process', async () => {
+    const manager = createManager();
+    const proc = manager.start('echo done');
+    await new Promise(resolve => setTimeout(resolve, 500));
+    expect(proc.status).toBe('exited');
+    expect(manager.kill(proc.id)).toBe(false);
+  });
+
+  it('captures stderr in output buffer', async () => {
+    const manager = createManager();
+    const proc = manager.start('echo "stderr msg" >&2');
+    await new Promise(resolve => setTimeout(resolve, 500));
+
+    const output = manager.getOutput(proc.id);
+    expect(output).toContain('stderr msg');
+  });
+
+  it('shutdown kills all running processes', async () => {
+    const manager = createManager();
+    const p1 = manager.start('sleep 60');
+    const p2 = manager.start('sleep 60');
+    expect(manager.runningCount()).toBe(2);
+
+    await manager.shutdown();
+
+    expect(p1.status).not.toBe('running');
+    expect(p2.status).not.toBe('running');
+  });
+
+  it('exposes config defaults', () => {
+    const manager = createManager();
+    expect(manager.config.maxConcurrent).toBe(10);
+    expect(manager.config.maxRuntimeMinutes).toBe(60);
+    expect(manager.config.bufferSize).toBe(65536);
+  });
+
+  it('exposes custom config', () => {
+    const manager = createManager({ maxConcurrent: 5, maxRuntimeMinutes: 30, bufferSize: 1024 });
+    expect(manager.config.maxConcurrent).toBe(5);
+    expect(manager.config.maxRuntimeMinutes).toBe(30);
+    expect(manager.config.bufferSize).toBe(1024);
+  });
+});
+
+describe('Process tools', () => {
+  let manager: ProcessManager;
+
+  afterEach(async () => {
+    if (manager) await manager.shutdown();
+  });
+
+  it('process.start tool creates and returns process info', async () => {
+    const { createProcessStartTool } = await import('./start.js');
+    manager = new ProcessManager();
+    const tool = createProcessStartTool(manager);
+
+    expect(tool.name).toBe('process.start');
+    const result = await tool.execute({ command: 'echo test' });
+    expect(result.success).toBe(true);
+    expect(result.output).toContain('proc_1');
+    expect(result.output).toContain('PID');
+
+    await new Promise(resolve => setTimeout(resolve, 300));
+  });
+
+  it('process.status tool returns status info', async () => {
+    const { createProcessStatusTool } = await import('./status.js');
+    manager = new ProcessManager();
+    const tool = createProcessStatusTool(manager);
+    manager.start('sleep 60');
+
+    const result = await tool.execute({ id: 'proc_1' });
+    expect(result.success).toBe(true);
+    expect(result.output).toContain('Status: running');
+    expect(result.output).toContain('proc_1');
+  });
+
+  it('process.status tool returns error for unknown ID', async () => {
+    const { createProcessStatusTool } = await import('./status.js');
+    manager = new ProcessManager();
+    const tool = createProcessStatusTool(manager);
+
+    const result = await tool.execute({ id: 'proc_999' });
+    expect(result.success).toBe(false);
+    expect(result.error).toContain('not found');
+  });
+
+  it('process.output tool returns process output', async () => {
+    const { createProcessOutputTool } = await import('./output.js');
+    manager = new ProcessManager();
+    const tool = createProcessOutputTool(manager);
+    manager.start('echo "tool output"');
+
+    await new Promise(resolve => setTimeout(resolve, 500));
+
+    const result = await tool.execute({ id: 'proc_1' });
+    expect(result.success).toBe(true);
+    expect(result.output).toContain('tool output');
+  });
+
+  it('process.kill tool kills a running process', async () => {
+    const { createProcessKillTool } = await import('./kill.js');
+    manager = new ProcessManager();
+    const tool = createProcessKillTool(manager);
+    manager.start('sleep 60');
+
+    const result = await tool.execute({ id: 'proc_1' });
+    expect(result.success).toBe(true);
+    expect(result.output).toContain('SIGTERM');
+
+    await new Promise(resolve => setTimeout(resolve, 300));
+  });
+
+  it('process.list tool lists all processes', async () => {
+    const { createProcessListTool } = await import('./list.js');
+    manager = new ProcessManager();
+    const tool = createProcessListTool(manager);
+
+    // Empty list
+    let result = await tool.execute({});
+    expect(result.success).toBe(true);
+    expect(result.output).toBe('No managed processes.');
+
+    // With processes
+    manager.start('sleep 60');
+    manager.start('echo hi');
+
+    await new Promise(resolve => setTimeout(resolve, 300));
+
+    result = await tool.execute({});
+    expect(result.success).toBe(true);
+    expect(result.output).toContain('proc_1');
+    expect(result.output).toContain('proc_2');
+  });
+
+  it('createProcessTools returns all 5 tools', async () => {
+    const { createProcessTools } = await import('./index.js');
+    manager = new ProcessManager();
+    const tools = createProcessTools(manager);
+    expect(tools).toHaveLength(5);
+    const names = tools.map(t => t.name);
+    expect(names).toContain('process.start');
+    expect(names).toContain('process.status');
+    expect(names).toContain('process.output');
+    expect(names).toContain('process.kill');
+    expect(names).toContain('process.list');
+  });
+});
diff --git a/src/tools/builtin/process/manager.ts b/src/tools/builtin/process/manager.ts
new file mode 100644
index 0000000..754383a
--- /dev/null
+++ b/src/tools/builtin/process/manager.ts
@@ -0,0 +1,289 @@
+import { spawn } from 'child_process';
+import type { ChildProcess } from 'child_process';
+
+/**
+ * RingBuffer — circular buffer for efficiently capturing process output.
+ * Keeps only the most recent `capacity` bytes, discarding older data.
+ */
+export class RingBuffer {
+  private buffer: Buffer;
+  private writePos = 0;
+  private length = 0;
+
+  constructor(private capacity: number = 65536) {
+    this.buffer = Buffer.alloc(capacity);
+  }
+
+  /** Write data into the ring buffer. Older data is overwritten when full. */
+  write(data: string | Buffer): void {
+    const buf = typeof data === 'string' ? Buffer.from(data) : data;
+
+    if (buf.length >= this.capacity) {
+      // Data larger than buffer — keep only the last `capacity` bytes
+      buf.copy(this.buffer, 0, buf.length - this.capacity);
+      this.writePos = 0;
+      this.length = this.capacity;
+      return;
+    }
+
+    // Handle wrap-around: write in up to two chunks
+    const firstChunk = Math.min(buf.length, this.capacity - this.writePos);
+    buf.copy(this.buffer, this.writePos, 0, firstChunk);
+    if (firstChunk < buf.length) {
+      buf.copy(this.buffer, 0, firstChunk);
+    }
+
+    this.writePos = (this.writePos + buf.length) % this.capacity;
+    this.length = Math.min(this.length + buf.length, this.capacity);
+  }
+
+  /** Read all buffered data as a UTF-8 string. */
+  read(): string {
+    if (this.length === 0) return '';
+
+    if (this.length < this.capacity) {
+      // Buffer not full — data is contiguous, starting at (writePos - length)
+      const start = this.writePos - this.length;
+      if (start >= 0) {
+        // Data sits in a single contiguous region
+        return this.buffer.subarray(start, this.writePos).toString('utf-8');
+      }
+      // Wrapped: data spans from (start + capacity) to end, then 0 to writePos
+      const tail = this.buffer.subarray(start + this.capacity);
+      const head = this.buffer.subarray(0, this.writePos);
+      return Buffer.concat([tail, head]).toString('utf-8');
+    }
+
+    // Buffer full — read from writePos (oldest) to end, then 0 to writePos (newest)
+    if (this.writePos === 0) {
+      // Special case: writePos wrapped to 0, entire buffer is valid in order
+      return this.buffer.toString('utf-8');
+    }
+    const end = this.buffer.subarray(this.writePos);
+    const start = this.buffer.subarray(0, this.writePos);
+    return Buffer.concat([end, start]).toString('utf-8');
+  }
+
+  /** Clear all buffered data. */
+  clear(): void {
+    this.writePos = 0;
+    this.length = 0;
+  }
+
+  /** Current amount of data stored (in bytes). */
+  get size(): number {
+    return this.length;
+  }
+}
+
+/** A background process managed by the ProcessManager. */
+export interface ManagedProcess {
+  id: string;
+  command: string;
+  cwd?: string;
+  pid: number;
+  status: 'running' | 'exited' | 'killed' | 'error';
+  exitCode?: number;
+  errorMessage?: string;
+  outputBuffer: RingBuffer;
+  startedAt: number;
+}
+
+export interface ProcessManagerConfig {
+  /** Maximum number of concurrent running processes (default 10). */
+  maxConcurrent?: number;
+  /** Maximum runtime in minutes before a process is killed (default 60). */
+  maxRuntimeMinutes?: number;
+  /** Ring buffer size in bytes for each process's output (default 65536 / 64KB). */
+  bufferSize?: number;
+}
+
+/**
+ * ProcessManager — manages background processes spawned by an AI agent.
+ *
+ * Features:
+ * - Enforces a concurrent process limit
+ * - Captures stdout/stderr into a fixed-size ring buffer per process
+ * - Automatically kills processes that exceed a configurable max runtime
+ * - Provides graceful shutdown with SIGTERM → SIGKILL escalation
+ */
+export class ProcessManager {
+  private processes = new Map<string, ManagedProcess>();
+  private childProcesses = new Map<string, ChildProcess>();
+  private nextId = 1;
+  private cleanupTimer: ReturnType<typeof setInterval> | null = null;
+  private _config: Required<ProcessManagerConfig>;
+
+  constructor(config: ProcessManagerConfig = {}) {
+    this._config = {
+      maxConcurrent: config.maxConcurrent ?? 10,
+      maxRuntimeMinutes: config.maxRuntimeMinutes ?? 60,
+      bufferSize: config.bufferSize ?? 65536,
+    };
+
+    // Periodic cleanup of expired processes (every 60 seconds)
+    this.cleanupTimer = setInterval(() => this._cleanupExpired(), 60_000);
+    // Ensure the timer doesn't keep the process alive
+    if (this.cleanupTimer.unref) {
+      this.cleanupTimer.unref();
+    }
+  }
+
+  get config(): Required<ProcessManagerConfig> {
+    return this._config;
+  }
+
+  /** Start a background process. Returns the managed process info. */
+  start(command: string, cwd?: string): ManagedProcess {
+    // Check concurrent limit
+    const running = this.runningCount();
+    if (running >= this._config.maxConcurrent) {
+      throw new Error(
+        `Maximum concurrent processes (${this._config.maxConcurrent}) reached. Kill a running process first.`,
+      );
+    }
+
+    const id = `proc_${this.nextId++}`;
+    const outputBuffer = new RingBuffer(this._config.bufferSize);
+
+    const child = spawn('bash', ['-c', command], {
+      cwd,
+      stdio: ['ignore', 'pipe', 'pipe'],
+      detached: false,
+    });
+
+    const proc: ManagedProcess = {
+      id,
+      command,
+      cwd,
+      pid: child.pid!,
+      status: 'running',
+      outputBuffer,
+      startedAt: Date.now(),
+    };
+
+    this.processes.set(id, proc);
+    this.childProcesses.set(id, child);
+
+    // Capture stdout and stderr into the ring buffer
+    child.stdout?.on('data', (data: Buffer) => {
+      outputBuffer.write(data);
+    });
+    child.stderr?.on('data', (data: Buffer) => {
+      outputBuffer.write(data);
+    });
+
+    // Handle process exit
+    child.on('exit', (code, signal) => {
+      if (signal === 'SIGKILL' || signal === 'SIGTERM') {
+        proc.status = 'killed';
+      } else {
+        proc.status = 'exited';
+      }
+      proc.exitCode = code ?? undefined;
+      this.childProcesses.delete(id);
+    });
+
+    // Handle spawn errors (e.g. command not found)
+    child.on('error', (err) => {
+      proc.status = 'error';
+      proc.errorMessage = err.message;
+      this.childProcesses.delete(id);
+    });
+
+    return proc;
+  }
+
+  /** Get a process by ID. */
+  get(id: string): ManagedProcess | undefined {
+    return this.processes.get(id);
+  }
+
+  /** Get recent output from a process's ring buffer. */
+  getOutput(id: string): string {
+    const proc = this.processes.get(id);
+    if (!proc) throw new Error(`Process ${id} not found`);
+    return proc.outputBuffer.read();
+  }
+
+  /** Kill a process by sending a signal. Returns true if signal was sent. */
+  kill(id: string, signal: NodeJS.Signals = 'SIGTERM'): boolean {
+    const proc = this.processes.get(id);
+    if (!proc) throw new Error(`Process ${id} not found`);
+    if (proc.status !== 'running') return false;
+
+    const child = this.childProcesses.get(id);
+    if (child) {
+      child.kill(signal);
+      return true;
+    }
+    return false;
+  }
+
+  /** List all managed processes. */
+  list(): ManagedProcess[] {
+    return Array.from(this.processes.values());
+  }
+
+  /** Count currently running processes. */
+  runningCount(): number {
+    let count = 0;
+    for (const proc of this.processes.values()) {
+      if (proc.status === 'running') count++;
+    }
+    return count;
+  }
+
+  /** Clean up expired processes that have exceeded the max runtime. */
+  private _cleanupExpired(): void {
+    const maxAge = this._config.maxRuntimeMinutes * 60_000;
+    const now = Date.now();
+    for (const [id, proc] of this.processes) {
+      if (proc.status === 'running' && (now - proc.startedAt) > maxAge) {
+        console.log(`[ProcessManager] Killing expired process ${id} (${proc.command})`);
+        this.kill(id, 'SIGKILL');
+      }
+    }
+  }
+
+  /** Shut down all running processes. Called on daemon shutdown. */
+  async shutdown(): Promise<void> {
+    if (this.cleanupTimer) {
+      clearInterval(this.cleanupTimer);
+      this.cleanupTimer = null;
+    }
+
+    const running = this.list().filter(p => p.status === 'running');
+    if (running.length === 0) return;
+
+    console.log(`[ProcessManager] Killing ${running.length} running process(es)...`);
+
+    // Send SIGTERM first for graceful shutdown
+    for (const proc of running) {
+      this.kill(proc.id, 'SIGTERM');
+    }
+
+    // Wait up to 5 seconds for graceful shutdown, then escalate to SIGKILL
+    await new Promise<void>((resolve) => {
+      const timeout = setTimeout(() => {
+        for (const proc of running) {
+          if (proc.status === 'running') {
+            this.kill(proc.id, 'SIGKILL');
+          }
+        }
+        resolve();
+      }, 5000);
+      timeout.unref?.();
+
+      // Check every 200ms if all processes have exited
+      const check = setInterval(() => {
+        if (running.every(p => p.status !== 'running')) {
+          clearTimeout(timeout);
+          clearInterval(check);
+          resolve();
+        }
+      }, 200);
+      check.unref?.();
+    });
+  }
+}
diff --git a/src/tools/builtin/process/output.ts b/src/tools/builtin/process/output.ts
new file mode 100644
index 0000000..33e6003
--- /dev/null
+++ b/src/tools/builtin/process/output.ts
@@ -0,0 +1,36 @@
+import type { Tool, ToolResult } from '../../types.js';
+import type { ProcessManager } from './manager.js';
+
+interface ProcessOutputArgs {
+  id: string;
+}
+
+export function createProcessOutputTool(manager: ProcessManager): Tool {
+  return {
+    name: 'process.output',
+    description: 'Read recent stdout/stderr output from a background process. Returns the last ~64KB of output.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        id: { type: 'string', description: 'Process ID (e.g. "proc_1")' },
+      },
+      required: ['id'],
+    },
+    execute: async (rawArgs: unknown): Promise<ToolResult> => {
+      const args = rawArgs as ProcessOutputArgs;
+      try {
+        const output = manager.getOutput(args.id);
+        if (!output) {
+          return { success: true, output: '(no output yet)' };
+        }
+        return { success: true, output };
+      } catch (error) {
+        return {
+          success: false,
+          output: '',
+          error: error instanceof Error ? error.message : 'Failed to get process output',
+        };
+      }
+    },
+  };
+}
diff --git a/src/tools/builtin/process/start.ts b/src/tools/builtin/process/start.ts
new file mode 100644
index 0000000..1bedc8e
--- /dev/null
+++ b/src/tools/builtin/process/start.ts
@@ -0,0 +1,38 @@
+import type { Tool, ToolResult } from '../../types.js';
+import type { ProcessManager } from './manager.js';
+
+interface ProcessStartArgs {
+  command: string;
+  cwd?: string;
+}
+
+export function createProcessStartTool(manager: ProcessManager): Tool {
+  return {
+    name: 'process.start',
+    description: 'Start a command in the background. Returns a process ID that can be used with process.status, process.output, and process.kill.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        command: { type: 'string', description: 'The shell command to run in the background' },
+        cwd: { type: 'string', description: 'Working directory (optional)' },
+      },
+      required: ['command'],
+    },
+    execute: async (rawArgs: unknown): Promise<ToolResult> => {
+      const args = rawArgs as ProcessStartArgs;
+      try {
+        const proc = manager.start(args.command, args.cwd);
+        return {
+          success: true,
+          output: `Started background process ${proc.id} (PID ${proc.pid})\nCommand: ${proc.command}`,
+        };
+      } catch (error) {
+        return {
+          success: false,
+          output: '',
+          error: error instanceof Error ? error.message : 'Failed to start process',
+        };
+      }
+    },
+  };
+}
diff --git a/src/tools/builtin/process/status.ts b/src/tools/builtin/process/status.ts
new file mode 100644
index 0000000..27c8dfc
--- /dev/null
+++ b/src/tools/builtin/process/status.ts
@@ -0,0 +1,42 @@
+import type { Tool, ToolResult } from '../../types.js';
+import type { ProcessManager } from './manager.js';
+
+interface ProcessStatusArgs {
+  id: string;
+}
+
+export function createProcessStatusTool(manager: ProcessManager): Tool {
+  return {
+    name: 'process.status',
+    description: 'Check the status of a background process by its ID.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        id: { type: 'string', description: 'Process ID (e.g. "proc_1")' },
+      },
+      required: ['id'],
+    },
+    execute: async (rawArgs: unknown): Promise<ToolResult> => {
+      const args = rawArgs as ProcessStatusArgs;
+      const proc = manager.get(args.id);
+      if (!proc) {
+        return { success: false, output: '', error: `Process ${args.id} not found` };
+      }
+
+      const uptime = proc.status === 'running'
+        ? `${Math.round((Date.now() - proc.startedAt) / 1000)}s`
+        : 'N/A';
+
+      let info = `Process: ${proc.id}\n`;
+      info += `Command: ${proc.command}\n`;
+      info += `PID: ${proc.pid}\n`;
+      info += `Status: ${proc.status}\n`;
+      info += `Uptime: ${uptime}\n`;
+      if (proc.exitCode !== undefined) info += `Exit code: ${proc.exitCode}\n`;
+      if (proc.errorMessage) info += `Error: ${proc.errorMessage}\n`;
+      if (proc.cwd) info += `CWD: ${proc.cwd}\n`;
+
+      return { success: true, output: info.trimEnd() };
+    },
+  };
+}
diff --git a/src/tools/builtin/web-search.test.ts b/src/tools/builtin/web-search.test.ts
new file mode 100644
index 0000000..e4ff5aa
--- /dev/null
+++ b/src/tools/builtin/web-search.test.ts
@@ -0,0 +1,258 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { createWebSearchTool } from './web-search.js';
+import type { WebSearchConfig } from './web-search.js';
+
+// Mock global fetch
+const mockFetch = vi.fn();
+vi.stubGlobal('fetch', mockFetch);
+
+beforeEach(() => {
+  mockFetch.mockReset();
+});
+
+// ── Helper: build mock Response objects ──────────────────────────────────────
+
+function mockJsonResponse(body: unknown, status = 200) {
+  return {
+    ok: status >= 200 && status < 300,
+    status,
+    text: async () => JSON.stringify(body),
+    json: async () => body,
+    headers: new Headers({ 'content-type': 'application/json' }),
+  };
+}
+
+// ── Brave mock data ──────────────────────────────────────────────────────────
+
+const braveResults = {
+  web: {
+    results: [
+      { title: 'Result 1', url: 'https://example.com/1', description: 'Description 1' },
+      { title: 'Result 2', url: 'https://example.com/2', description: 'Description 2' },
+      { title: 'Result 3', url: 'https://example.com/3', description: 'Description 3' },
+      { title: 'Result 4', url: 'https://example.com/4', description: 'Description 4' },
+      { title: 'Result 5', url: 'https://example.com/5', description: 'Description 5' },
+    ],
+  },
+};
+
+// ── SearXNG mock data ────────────────────────────────────────────────────────
+
+const searxngResults = {
+  results: [
+    { title: 'Result 1', url: 'https://example.com/1', content: 'Content 1' },
+    { title: 'Result 2', url: 'https://example.com/2', content: 'Content 2' },
+    { title: 'Result 3', url: 'https://example.com/3', content: 'Content 3' },
+    { title: 'Result 4', url: 'https://example.com/4', content: 'Content 4' },
+    { title: 'Result 5', url: 'https://example.com/5', content: 'Content 5' },
+  ],
+};
+
+// ── Brave config ─────────────────────────────────────────────────────────────
+
+const braveConfig: WebSearchConfig = {
+  provider: 'brave',
+  apiKey: 'test-brave-key',
+};
+
+// ── SearXNG config ───────────────────────────────────────────────────────────
+
+const searxngConfig: WebSearchConfig = {
+  provider: 'searxng',
+  endpoint: 'http://searxng:8080',
+};
+
+// ═════════════════════════════════════════════════════════════════════════════
+// Tests
+// ═════════════════════════════════════════════════════════════════════════════
+
+describe('web.search', () => {
+  // ── Metadata ─────────────────────────────────────────────────────────────
+
+  it('has correct metadata', () => {
+    const tool = createWebSearchTool(braveConfig);
+    expect(tool.name).toBe('web.search');
+    expect(tool.description).toBeTruthy();
+    expect(tool.inputSchema.required).toContain('query');
+  });
+
+  // ── Brave provider ──────────────────────────────────────────────────────
+
+  describe('brave provider', () => {
+    it('returns formatted results on successful search', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(braveResults));
+      const tool = createWebSearchTool(braveConfig);
+
+      const result = await tool.execute({ query: 'test query' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('**Result 1**');
+      expect(result.output).toContain('https://example.com/1');
+      expect(result.output).toContain('Description 1');
+      expect(result.output).toContain('**Result 2**');
+      expect(result.output).toContain('https://example.com/2');
+      expect(result.output).toContain('Description 2');
+
+      // Verify fetch was called with correct URL and headers
+      expect(mockFetch).toHaveBeenCalledWith(
+        expect.stringContaining('api.search.brave.com'),
+        expect.objectContaining({
+          headers: expect.objectContaining({
+            'X-Subscription-Token': 'test-brave-key',
+          }),
+        }),
+      );
+    });
+
+    it('handles empty results', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse({ web: { results: [] } }));
+      const tool = createWebSearchTool(braveConfig);
+
+      const result = await tool.execute({ query: 'obscure query' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toBe('No results found for: obscure query');
+    });
+
+    it('returns error when no API key configured', async () => {
+      const tool = createWebSearchTool({ provider: 'brave' });
+
+      const result = await tool.execute({ query: 'test' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toBe('Brave Search API key not configured');
+      expect(mockFetch).not.toHaveBeenCalled();
+    });
+
+    it('handles HTTP errors from Brave API', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse({ error: 'rate limited' }, 429));
+      const tool = createWebSearchTool(braveConfig);
+
+      const result = await tool.execute({ query: 'test' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('429');
+    });
+
+    it('handles network errors', async () => {
+      mockFetch.mockRejectedValue(new Error('Failed to fetch'));
+      const tool = createWebSearchTool(braveConfig);
+
+      const result = await tool.execute({ query: 'test' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('Failed to fetch');
+    });
+  });
+
+  // ── SearXNG provider ────────────────────────────────────────────────────
+
+  describe('searxng provider', () => {
+    it('returns formatted results on successful search', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(searxngResults));
+      const tool = createWebSearchTool(searxngConfig);
+
+      const result = await tool.execute({ query: 'test query' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('**Result 1**');
+      expect(result.output).toContain('https://example.com/1');
+      expect(result.output).toContain('Content 1');
+      expect(result.output).toContain('**Result 2**');
+
+      // Verify fetch was called with correct URL
+      expect(mockFetch).toHaveBeenCalledWith(
+        expect.stringContaining('http://searxng:8080/search'),
+        expect.any(Object),
+      );
+      // Verify query params include format=json
+      const calledUrl = mockFetch.mock.calls[0][0] as string;
+      expect(calledUrl).toContain('format=json');
+      expect(calledUrl).toContain('categories=general');
+    });
+
+    it('handles empty results', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse({ results: [] }));
+      const tool = createWebSearchTool(searxngConfig);
+
+      const result = await tool.execute({ query: 'nothing here' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toBe('No results found for: nothing here');
+    });
+
+    it('returns error when no endpoint configured', async () => {
+      const tool = createWebSearchTool({ provider: 'searxng' });
+
+      const result = await tool.execute({ query: 'test' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toBe('SearXNG endpoint not configured');
+      expect(mockFetch).not.toHaveBeenCalled();
+    });
+  });
+
+  // ── Count parameter ─────────────────────────────────────────────────────
+
+  describe('count parameter', () => {
+    it('limits results to the requested count', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(braveResults));
+      const tool = createWebSearchTool(braveConfig);
+
+      const result = await tool.execute({ query: 'test', count: 2 });
+
+      expect(result.success).toBe(true);
+      // Verify count=2 was passed to the Brave API
+      const calledUrl = mockFetch.mock.calls[0][0] as string;
+      expect(calledUrl).toContain('count=2');
+    });
+
+    it('caps count at 20', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(braveResults));
+      const tool = createWebSearchTool(braveConfig);
+
+      await tool.execute({ query: 'test', count: 50 });
+
+      // Verify count was capped at 20
+      const calledUrl = mockFetch.mock.calls[0][0] as string;
+      expect(calledUrl).toContain('count=20');
+    });
+
+    it('uses default count when not specified', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(braveResults));
+      const tool = createWebSearchTool(braveConfig);
+
+      await tool.execute({ query: 'test' });
+
+      // Default count is 5
+      const calledUrl = mockFetch.mock.calls[0][0] as string;
+      expect(calledUrl).toContain('count=5');
+    });
+
+    it('respects maxResults from config', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(braveResults));
+      const tool = createWebSearchTool({ ...braveConfig, maxResults: 3 });
+
+      await tool.execute({ query: 'test' });
+
+      const calledUrl = mockFetch.mock.calls[0][0] as string;
+      expect(calledUrl).toContain('count=3');
+    });
+  });
+
+  // ── Output format ───────────────────────────────────────────────────────
+
+  describe('output format', () => {
+    it('formats results as numbered markdown', async () => {
+      mockFetch.mockResolvedValue(mockJsonResponse(braveResults));
+      const tool = createWebSearchTool(braveConfig);
+
+      const result = await tool.execute({ query: 'test', count: 2 });
+
+      expect(result.success).toBe(true);
+      // Check numbered format with em-dash separator
+      expect(result.output).toMatch(/^1\. \*\*Result 1\*\* \u2014 https:\/\/example\.com\/1/);
+      expect(result.output).toContain('2. **Result 2**');
+    });
+  });
+});
diff --git a/src/tools/builtin/web-search.ts b/src/tools/builtin/web-search.ts
new file mode 100644
index 0000000..6d56c81
--- /dev/null
+++ b/src/tools/builtin/web-search.ts
@@ -0,0 +1,195 @@
+import type { Tool, ToolResult } from '../types.js';
+
+/** Configuration for the web search tool. */
+export interface WebSearchConfig {
+  provider: 'brave' | 'searxng';
+  /** Required for Brave Search API. */
+  apiKey?: string;
+  /** Required for SearXNG (e.g. 'http://searxng:8080'). */
+  endpoint?: string;
+  /** Maximum number of results to return (default: 5). */
+  maxResults?: number;
+}
+
+interface WebSearchArgs {
+  query: string;
+  count?: number;
+}
+
+interface SearchResult {
+  title: string;
+  url: string;
+  snippet: string;
+}
+
+/** Fetch timeout in milliseconds. */
+const FETCH_TIMEOUT_MS = 10_000;
+
+/** Maximum allowed result count. */
+const MAX_RESULTS = 20;
+
+/** Default result count. */
+const DEFAULT_RESULTS = 5;
+
+/**
+ * Format search results as numbered markdown.
+ */
+function formatResults(results: SearchResult[]): string {
+  return results
+    .map(
+      (r, i) => `${i + 1}. **${r.title}** \u2014 ${r.url}\n   ${r.snippet}`,
+    )
+    .join('\n\n');
+}
+
+/**
+ * Search using the Brave Search API.
+ */
+async function searchBrave(
+  query: string,
+  count: number,
+  apiKey: string,
+): Promise<SearchResult[]> {
+  const params = new URLSearchParams({
+    q: query,
+    count: String(count),
+  });
+
+  const response = await fetch(
+    `https://api.search.brave.com/res/v1/web/search?${params.toString()}`,
+    {
+      signal: AbortSignal.timeout(FETCH_TIMEOUT_MS),
+      headers: {
+        'Accept': 'application/json',
+        'X-Subscription-Token': apiKey,
+      },
+    },
+  );
+
+  if (!response.ok) {
+    const body = await response.text();
+    throw new Error(`Brave API HTTP ${response.status}: ${body}`);
+  }
+
+  const data = (await response.json()) as {
+    web?: { results?: Array<{ title: string; url: string; description: string }> };
+  };
+
+  const rawResults = data.web?.results ?? [];
+  return rawResults.map((r) => ({
+    title: r.title,
+    url: r.url,
+    snippet: r.description,
+  }));
+}
+
+/**
+ * Search using a self-hosted SearXNG instance.
+ */
+async function searchSearxng(
+  query: string,
+  count: number,
+  endpoint: string,
+): Promise<SearchResult[]> {
+  // Strip trailing slash from endpoint
+  const baseUrl = endpoint.replace(/\/+$/, '');
+  const params = new URLSearchParams({
+    q: query,
+    format: 'json',
+    categories: 'general',
+  });
+
+  const response = await fetch(`${baseUrl}/search?${params.toString()}`, {
+    signal: AbortSignal.timeout(FETCH_TIMEOUT_MS),
+    headers: {
+      'Accept': 'application/json',
+    },
+  });
+
+  if (!response.ok) {
+    const body = await response.text();
+    throw new Error(`SearXNG HTTP ${response.status}: ${body}`);
+  }
+
+  const data = (await response.json()) as {
+    results?: Array<{ title: string; url: string; content: string }>;
+  };
+
+  const rawResults = (data.results ?? []).slice(0, count);
+  return rawResults.map((r) => ({
+    title: r.title,
+    url: r.url,
+    snippet: r.content,
+  }));
+}
+
+/**
+ * Creates a web.search tool configured for the given search provider.
+ *
+ * Supports Brave Search API and self-hosted SearXNG.
+ */
+export function createWebSearchTool(config: WebSearchConfig): Tool {
+  const defaultCount = config.maxResults ?? DEFAULT_RESULTS;
+
+  return {
+    name: 'web.search',
+    description:
+      'Search the web for current information. Returns titles, URLs, and snippets from web search results. Use this to find up-to-date information about any topic.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        query: { type: 'string', description: 'Search query' },
+        count: {
+          type: 'number',
+          description: 'Number of results to return (default 5, max 20)',
+        },
+      },
+      required: ['query'],
+    },
+    execute: async (rawArgs: unknown): Promise<ToolResult> => {
+      const args = rawArgs as WebSearchArgs;
+      // Clamp count: use provided value (capped at MAX_RESULTS), or fall back to default
+      const count = Math.min(args.count ?? defaultCount, MAX_RESULTS);
+
+      try {
+        let results: SearchResult[];
+
+        if (config.provider === 'brave') {
+          if (!config.apiKey) {
+            return {
+              success: false,
+              output: '',
+              error: 'Brave Search API key not configured',
+            };
+          }
+          results = await searchBrave(args.query, count, config.apiKey);
+        } else {
+          // SearXNG provider
+          if (!config.endpoint) {
+            return {
+              success: false,
+              output: '',
+              error: 'SearXNG endpoint not configured',
+            };
+          }
+          results = await searchSearxng(args.query, count, config.endpoint);
+        }
+
+        if (results.length === 0) {
+          return {
+            success: true,
+            output: `No results found for: ${args.query}`,
+          };
+        }
+
+        return { success: true, output: formatResults(results) };
+      } catch (error) {
+        return {
+          success: false,
+          output: '',
+          error: error instanceof Error ? error.message : String(error),
+        };
+      }
+    },
+  };
+}