diff --git a/src/agents/launch.js b/src/agents/launch.js
new file mode 100644
index 00000000..7f9008b1
--- /dev/null
+++ b/src/agents/launch.js
@@ -0,0 +1,240 @@
+'use strict';
+
+let registryModule = {};
+let registryPath = null;
+
+try {
+  registryPath = require.resolve('./registry');
+} catch (error) {
+  if (error && error.code !== 'MODULE_NOT_FOUND') {
+    throw error;
+  }
+}
+
+if (registryPath) {
+  registryModule = require(registryPath);
+}
+
+const FALLBACK_AGENTS = {
+  codex: {
+    command: 'codex',
+    promptMode: 'positional',
+    resumeCommand: ['codex', 'resume'],
+    permissionFlag: '--permission-mode',
+  },
+  claude: {
+    command: 'claude',
+    promptMode: 'option',
+    promptFlag: '--prompt',
+    resumeCommand: ['claude', '--continue'],
+    permissionFlag: '--permission-mode',
+  },
+  opencode: {
+    command: 'opencode',
+    promptMode: 'positional',
+    resumeCommand: ['opencode', 'resume'],
+    permissionFlag: '--permission-mode',
+  },
+  cursor: {
+    command: 'cursor-agent',
+    promptMode: 'stdin',
+    resumeCommand: ['cursor-agent', 'resume'],
+    permissionFlag: '--permission-mode',
+  },
+  gemini: {
+    command: 'gemini',
+    promptMode: 'option',
+    promptFlag: '--prompt',
+    resumeCommand: ['gemini', 'resume'],
+    permissionFlag: '--permission-mode',
+  },
+};
+
+const SUPPORTED_PROMPT_MODES = new Set(['positional', 'option', 'stdin']);
+
+function shellQuote(value) {
+  const stringValue = String(value);
+  if (stringValue.length === 0) return "''";
+  return `'${stringValue.replace(/'/g, `'\\''`)}'`;
+}
+
+function normalizeCommandParts(command) {
+  if (Array.isArray(command)) return command.map(String);
+  if (command && typeof command === 'object') {
+    return [
+      ...normalizeCommandParts(command.command || command.executable || command.bin),
+      ...normalizeCommandParts(command.args || command.defaultArgs),
+    ];
+  }
+  if (typeof command === 'string' && command.trim()) return [command];
+  return [];
+}
+
+function normalizeAgentsCollection(collection) {
+  if (!collection) return null;
+  if (collection instanceof Map) return Object.fromEntries(collection.entries());
+  if (Array.isArray(collection)) {
+    return Object.fromEntries(collection.map((agent) => [agent.id || agent.agentId || agent.name, agent]));
+  }
+  if (typeof collection === 'object') return collection;
+  return null;
+}
+
+function getRegistryAgent(agentId) {
+  const lookupFunctions = [
+    registryModule.getAgent,
+    registryModule.getAgentById,
+    registryModule.getAgentDefinition,
+    registryModule.resolveAgent,
+  ].filter((candidate) => typeof candidate === 'function');
+
+  for (const lookup of lookupFunctions) {
+    const agent = lookup(agentId);
+    if (agent) return agent;
+  }
+
+  const collections = [
+    registryModule.AGENTS,
+    registryModule.AGENT_REGISTRY,
+    registryModule.SUPPORTED_AGENTS,
+    registryModule.agents,
+    registryModule.registry,
+    registryModule.default,
+  ];
+
+  for (const collection of collections) {
+    const normalized = normalizeAgentsCollection(collection);
+    if (normalized && normalized[agentId]) return normalized[agentId];
+  }
+
+  return null;
+}
+
+function resolveAgent(agentId) {
+  if (!agentId || typeof agentId !== 'string') {
+    throw new TypeError('agentId is required');
+  }
+
+  const registryAgent = getRegistryAgent(agentId);
+  const fallbackAgent = FALLBACK_AGENTS[agentId];
+  const agent = { ...fallbackAgent, ...registryAgent };
+
+  if (!agent || (!agent.command && !agent.executable && !agent.bin)) {
+    throw new Error(`Unsupported agent: ${agentId}`);
+  }
+
+  return agent;
+}
+
+function buildPermissionParts(agent, permissionMode) {
+  if (!permissionMode) return [];
+
+  if (typeof agent.buildPermissionArgs === 'function') {
+    return normalizeCommandParts(agent.buildPermissionArgs(permissionMode));
+  }
+
+  const flag = agent.permissionFlag ||
+    agent.permissionModeFlag ||
+    agent.permission?.flag ||
+    agent.permissionMode?.flag;
+  if (!flag) return [];
+  return [flag, permissionMode];
+}
+
+function buildSessionParts(agent, sessionId) {
+  if (!sessionId) return [];
+
+  if (typeof agent.buildSessionArgs === 'function') {
+    return normalizeCommandParts(agent.buildSessionArgs(sessionId));
+  }
+
+  const flag = agent.sessionFlag || agent.sessionIdFlag || agent.session?.flag;
+  if (!flag) return [];
+  return [flag, sessionId];
+}
+
+function buildSessionEnv(agent, sessionId) {
+  if (!sessionId) return [];
+  const envVar = agent.sessionEnvVar || agent.session?.env || 'OMX_SESSION_ID';
+  return [`${envVar}=${shellQuote(sessionId)}`];
+}
+
+function commandToShell(parts) {
+  return parts.map(shellQuote).join(' ');
+}
+
+function buildPromptCommand(parts, agent, prompt) {
+  if (prompt === undefined || prompt === null || prompt === '') {
+    return commandToShell(parts);
+  }
+
+  const promptMode = agent.promptMode || agent.prompt?.mode || 'positional';
+  if (!SUPPORTED_PROMPT_MODES.has(promptMode)) {
+    throw new Error(`Unsupported prompt mode for ${agent.id || agent.command}: ${promptMode}`);
+  }
+
+  if (promptMode === 'stdin') {
+    return `printf %s ${shellQuote(prompt)} | ${commandToShell(parts)}`;
+  }
+
+  if (promptMode === 'option') {
+    const promptFlag = agent.promptFlag || agent.promptOption || agent.prompt?.flag || agent.prompt?.option || '--prompt';
+    return commandToShell([...parts, promptFlag, prompt]);
+  }
+
+  return commandToShell([...parts, prompt]);
+}
+
+function buildAgentLaunchCommand(options) {
+  if (!options || typeof options !== 'object') {
+    throw new TypeError('options are required');
+  }
+
+  const { agentId, prompt, worktreePath, permissionMode, sessionId } = options;
+  const agent = resolveAgent(agentId);
+  const command = normalizeCommandParts(agent.launchCommand || agent.launch || agent.command || agent.executable || agent.bin);
+  const baseParts = [
+    ...command,
+    ...normalizeCommandParts(agent.defaultArgs),
+    ...normalizeCommandParts(agent.args),
+    ...normalizeCommandParts(agent.launchArgs),
+    ...buildPermissionParts(agent, permissionMode),
+    ...buildSessionParts(agent, sessionId),
+  ];
+
+  if (baseParts.length === 0) {
+    throw new Error(`Unsupported agent: ${agentId}`);
+  }
+
+  const launchCommand = buildPromptCommand(baseParts, agent, prompt);
+  const envPrefix = buildSessionEnv(agent, sessionId).join(' ');
+  const launchWithEnv = envPrefix ? `${envPrefix} ${launchCommand}` : launchCommand;
+  if (!worktreePath) return launchWithEnv;
+  return `cd ${shellQuote(worktreePath)} && ${launchWithEnv}`;
+}
+
+function buildAgentResumeCommand(agentId, permissionMode) {
+  const agent = resolveAgent(agentId);
+  const commandParts = normalizeCommandParts(agent.command || agent.executable || agent.bin);
+  const explicitResume = agent.resumeCommand || agent.resume;
+  const resumeArgs = normalizeCommandParts(agent.resumeArgs);
+  const resumeParts = explicitResume
+    ? normalizeCommandParts(explicitResume)
+    : [...commandParts, ...(resumeArgs.length > 0 ? resumeArgs : ['resume'])];
+  const command = [
+    ...resumeParts,
+    ...buildPermissionParts(agent, permissionMode),
+  ];
+
+  if (command.length === 0) {
+    throw new Error(`Unsupported agent: ${agentId}`);
+  }
+
+  return commandToShell(command);
+}
+
+module.exports = {
+  buildAgentLaunchCommand,
+  buildAgentResumeCommand,
+  shellQuote,
+};
diff --git a/test/agents-launch.test.js b/test/agents-launch.test.js
new file mode 100644
index 00000000..941aaac1
--- /dev/null
+++ b/test/agents-launch.test.js
@@ -0,0 +1,106 @@
+'use strict';
+
+const assert = require('node:assert/strict');
+const test = require('node:test');
+
+const {
+  buildAgentLaunchCommand,
+  buildAgentResumeCommand,
+} = require('../src/agents/launch');
+
+test('builds codex launch commands with positional prompts', () => {
+  assert.equal(
+    buildAgentLaunchCommand({
+      agentId: 'codex',
+      prompt: 'fix tests',
+      worktreePath: '/tmp/work tree',
+      permissionMode: 'workspace-write',
+      sessionId: 'session-1',
+    }),
+    "cd '/tmp/work tree' && OMX_SESSION_ID='session-1' 'codex' '--permission-mode' 'workspace-write' 'fix tests'",
+  );
+});
+
+test('builds claude launch commands with option prompts', () => {
+  assert.equal(
+    buildAgentLaunchCommand({
+      agentId: 'claude',
+      prompt: 'review code',
+      permissionMode: 'acceptEdits',
+    }),
+    "'claude' '--permission-mode' 'acceptEdits' '--prompt' 'review code'",
+  );
+});
+
+test('builds opencode launch commands with positional prompts', () => {
+  assert.equal(
+    buildAgentLaunchCommand({
+      agentId: 'opencode',
+      prompt: 'implement feature',
+    }),
+    "'opencode' 'implement feature'",
+  );
+});
+
+test('builds cursor launch commands with stdin prompts', () => {
+  assert.equal(
+    buildAgentLaunchCommand({
+      agentId: 'cursor',
+      prompt: 'inspect current branch',
+      worktreePath: '/repo/worktree',
+    }),
+    "cd '/repo/worktree' && printf %s 'inspect current branch' | 'cursor-agent'",
+  );
+});
+
+test('builds gemini launch commands with option prompts', () => {
+  assert.equal(
+    buildAgentLaunchCommand({
+      agentId: 'gemini',
+      prompt: 'summarize repo',
+      sessionId: 'session-2',
+    }),
+    "OMX_SESSION_ID='session-2' 'gemini' '--prompt' 'summarize repo'",
+  );
+});
+
+test('quotes prompts with single quotes, newlines, and dollar signs safely', () => {
+  const prompt = "say 'hello'\nthen echo $HOME";
+
+  assert.equal(
+    buildAgentLaunchCommand({ agentId: 'codex', prompt }),
+    "'codex' 'say '\\''hello'\\''\nthen echo $HOME'",
+  );
+
+  assert.equal(
+    buildAgentLaunchCommand({ agentId: 'gemini', prompt }),
+    "'gemini' '--prompt' 'say '\\''hello'\\''\nthen echo $HOME'",
+  );
+
+  assert.equal(
+    buildAgentLaunchCommand({ agentId: 'cursor', prompt }),
+    "printf %s 'say '\\''hello'\\''\nthen echo $HOME' | 'cursor-agent'",
+  );
+});
+
+test('omits prompts when none are supplied', () => {
+  assert.equal(
+    buildAgentLaunchCommand({ agentId: 'codex', worktreePath: '/repo' }),
+    "cd '/repo' && 'codex'",
+  );
+});
+
+test('builds resume commands for supported agents', () => {
+  assert.equal(buildAgentResumeCommand('codex', 'workspace-write'), "'codex' 'resume' '--permission-mode' 'workspace-write'");
+  assert.equal(buildAgentResumeCommand('claude'), "'claude' '--continue'");
+  assert.equal(buildAgentResumeCommand('opencode'), "'opencode' 'resume'");
+  assert.equal(buildAgentResumeCommand('cursor'), "'cursor-agent' 'resume'");
+  assert.equal(buildAgentResumeCommand('gemini'), "'gemini' 'resume'");
+});
+
+test('rejects unsupported agents', () => {
+  assert.throws(
+    () => buildAgentLaunchCommand({ agentId: 'unknown', prompt: 'x' }),
+    /Unsupported agent: unknown/,
+  );
+});