diff --git a/src/main/acp/acp-dialects/omp-dialect.test.ts b/src/main/acp/acp-dialects/omp-dialect.test.ts
new file mode 100644
index 000000000000..5c6b3cb059b7
--- /dev/null
+++ b/src/main/acp/acp-dialects/omp-dialect.test.ts
@@ -0,0 +1,48 @@
+import { describe, expect, it } from 'vitest'
+import type { ToolCallUpdate } from '../generated/acp-protocol.generated'
+import { OMP_ACP_DIALECT } from './omp-dialect'
+
+const text = (value: string) => ({
+  type: 'content' as const,
+  content: { type: 'text' as const, text: value }
+})
+const normalize = (update: ToolCallUpdate) => OMP_ACP_DIALECT.normalizeToolUpdate!(update)
+
+describe('OMP tool updates', () => {
+  it('leaves a tool without a command echo as it came', () => {
+    const update: ToolCallUpdate = {
+      toolCallId: 'call-1',
+      status: 'completed',
+      rawOutput: { content: [{ type: 'text', text: 'file body' }], details: {} },
+      content: [text('file body')]
+    }
+    expect(normalize(update)).toBe(update)
+  })
+
+  it('keeps a result that itself starts with "$ "', () => {
+    const update: ToolCallUpdate = {
+      toolCallId: 'call-1',
+      status: 'completed',
+      rawOutput: { content: [{ type: 'text', text: '$ 5.00' }], details: {} },
+      content: [text('$ 5.00')]
+    }
+    expect(normalize(update)).toBe(update)
+  })
+
+  it('keeps output that only looks like a notice when OMP sent no matching detail', () => {
+    const update = normalize({
+      toolCallId: 'call-1',
+      status: 'completed',
+      rawOutput: {
+        content: [{ type: 'text', text: 'done\n\nCommand exited with code 3' }],
+        details: {}
+      },
+      content: [text('$ ./run'), text('done\n\nCommand exited with code 3')]
+    })
+    expect(update).toMatchObject({
+      content: [],
+      rawOutput: { stdout: 'done\n\nCommand exited with code 3' }
+    })
+    expect(update.rawOutput).not.toHaveProperty('exitCode')
+  })
+})
diff --git a/src/main/acp/acp-dialects/omp-dialect.ts b/src/main/acp/acp-dialects/omp-dialect.ts
new file mode 100644
index 000000000000..cb7e321d8228
--- /dev/null
+++ b/src/main/acp/acp-dialects/omp-dialect.ts
@@ -0,0 +1,66 @@
+import { z } from 'zod'
+import type { ToolCallContent, ToolCallUpdate } from '../generated/acp-protocol.generated'
+import type { AcpDialect } from './acp-dialect'
+
+// OMP sends a tool's result as `rawOutput: {content: [{type: 'text', text}], details}`, with a
+// command's non-zero exit at `details.exitCode`, and repeats the text as content behind a
+// `$ <command>` echo. The shared reader takes content text first, so that echo became the output.
+const textBlockSchema = z.looseObject({ type: z.literal('text'), text: z.string() })
+const toolResultSchema = z.looseObject({
+  content: z.array(z.unknown()),
+  details: z
+    .looseObject({
+      exitCode: z.number().int().safe().optional(),
+      wallTimeMs: z.number().optional()
+    })
+    .optional()
+})
+
+function contentText(block: ToolCallContent | undefined): string | undefined {
+  return block?.type === 'content' && block.content.type === 'text' ? block.content.text : undefined
+}
+
+/** OMP appends these notice lines to a command's output; the row shows exit and timing itself. */
+function commandOutput(text: string, exitCode: number | undefined, timed: boolean): string {
+  let output = text
+  const exitNotice = `\n\nCommand exited with code ${exitCode}`
+  if (exitCode !== undefined && output.endsWith(exitNotice)) {
+    output = output.slice(0, -exitNotice.length)
+  }
+  return timed ? output.replace(/\n\nWall time: \d+(?:\.\d+)? seconds$/u, '') : output
+}
+
+function normalizeToolUpdate(update: ToolCallUpdate): ToolCallUpdate {
+  const echo = contentText(update.content?.[0])
+  if (!echo?.startsWith('$ ')) {
+    return update
+  }
+  const parsed = toolResultSchema.safeParse(update.rawOutput)
+  const texts = parsed.success
+    ? parsed.data.content.flatMap((block) => textBlockSchema.safeParse(block).data?.text ?? [])
+    : []
+  if (texts.includes(echo)) {
+    return update
+  }
+  // The result's own text moves to `stdout`; content keeps anything else it carried.
+  const content = (update.content ?? []).slice(1).filter((block) => {
+    const text = contentText(block)
+    return text === undefined || !texts.includes(text)
+  })
+  if (!parsed.success) {
+    return { ...update, content }
+  }
+  const exitCode = parsed.data.details?.exitCode
+  const stdout = commandOutput(
+    texts.join('\n'),
+    exitCode,
+    parsed.data.details?.wallTimeMs !== undefined
+  )
+  return {
+    ...update,
+    content,
+    rawOutput: { ...parsed.data, stdout, ...(exitCode === undefined ? {} : { exitCode }) }
+  }
+}
+
+export const OMP_ACP_DIALECT: AcpDialect = { normalizeToolUpdate }
diff --git a/src/main/acp/acp-launch-specs.ts b/src/main/acp/acp-launch-specs.ts
index dcf91c1d4f8d..958d787406d2 100644
--- a/src/main/acp/acp-launch-specs.ts
+++ b/src/main/acp/acp-launch-specs.ts
@@ -9,13 +9,14 @@ import {
 import { AGENT_HOOK_RUNTIME_ENV_KEYS } from '../ipc/pty/host-env/spawn-env-keys'
 import type { AcpDialect } from './acp-dialects/acp-dialect'
 import { GROK_ACP_DIALECT } from './acp-dialects/grok-dialect'
+import { OMP_ACP_DIALECT } from './acp-dialects/omp-dialect'
 import { OPENCODE_ACP_DIALECT } from './acp-dialects/opencode-dialect'
 import { directoryAccountBinding, type AcpAccountBinding } from './acp-account-binding'
 import { openCodeAcpAccountBinding } from '../opencode/opencode-structured-account-home'
 import { scrubOpenCodeAcpEnvironment } from '../opencode/opencode-acp-environment'
 import { openCodeStoredUserMessagesReader } from '../opencode/opencode-acp-stored-messages'
 import type { AcpStoredUserMessagesReader } from './acp-recovery-history'
-import { isStableCliVersionOnLine } from '../agent-cli-version-probe'
+import { isStableCliVersionFrom, isStableCliVersionOnLine } from '../agent-cli-version-probe'
 import type { TuiAgent } from '../../shared/tui-agent'
 
 export type AcpLaunchSpec = {
@@ -92,7 +93,31 @@ const OPENCODE_LAUNCH_SPEC: AcpLaunchSpec = {
   readStoredUserMessages: openCodeStoredUserMessagesReader()
 }
 
-export const ACP_LAUNCH_SPECS: readonly AcpLaunchSpec[] = [GROK_LAUNCH_SPEC, OPENCODE_LAUNCH_SPEC]
+// OMP serves ACP through `omp acp`; its environment reaches it as the user set it.
+const OMP_LAUNCH_SPEC: AcpLaunchSpec = {
+  agent: 'omp',
+  command: 'omp',
+  // `omp acp` takes no flags: full access answers each permission request yes.
+  args: () => ['acp'],
+  env: {},
+  dialect: OMP_ACP_DIALECT,
+  // OMP signs in from its own `/login`.
+  loginCommand: ['omp'],
+  // The directory OMP's terminal chats read too; its default is OMP's own.
+  account: directoryAccountBinding('PI_CODING_AGENT_DIR', (homePath) =>
+    join(homePath, '.omp', 'agent')
+  ),
+  // OMP's installers use directories the shared resolver already searches after PATH.
+  installDirectories: () => [],
+  // Stable releases from 17.0.5, the release verified to serve `omp acp`.
+  supportsVersion: (version) => isStableCliVersionFrom(version, '17.0.5')
+}
+
+export const ACP_LAUNCH_SPECS: readonly AcpLaunchSpec[] = [
+  GROK_LAUNCH_SPEC,
+  OPENCODE_LAUNCH_SPEC,
+  OMP_LAUNCH_SPEC
+]
 
 export function acpLaunchSpecFor(agent: string): AcpLaunchSpec | null {
   return ACP_LAUNCH_SPECS.find((spec) => spec.agent === agent) ?? null
diff --git a/src/main/acp/acp-structured-launch-resolution-omp.test.ts b/src/main/acp/acp-structured-launch-resolution-omp.test.ts
new file mode 100644
index 000000000000..8e34dee2e9d7
--- /dev/null
+++ b/src/main/acp/acp-structured-launch-resolution-omp.test.ts
@@ -0,0 +1,132 @@
+import { describe, expect, it } from 'vitest'
+import type { AgentSessionRecord } from '../../shared/agent-session-record'
+import { agentSessionRecordFixture } from '../../shared/agent-session-record.test-fixture'
+import { createProviderSpawnSpec } from '../provider-process/provider-process-supervisor'
+import { ACP_CHILD_ENV_TO_DELETE, acpLaunchSpecFor } from './acp-launch-specs'
+import {
+  createAcpStructuredLaunchResolver,
+  type AcpStructuredLaunchResolverDeps
+} from './acp-structured-launch-resolution'
+
+const OMP = acpLaunchSpecFor('omp')!
+const identity = {
+  sessionId: 'session-alpha-1',
+  workspaceId: 'workspace-1',
+  hostId: 'local',
+  agent: 'omp',
+  providerHandle: null
+}
+
+function ompRecord(
+  accountHome: AgentSessionRecord['accountHome'] = {
+    variable: 'PI_CODING_AGENT_DIR',
+    path: '/home/user/.omp/agent'
+  }
+): AgentSessionRecord {
+  return { ...agentSessionRecordFixture(), provider: 'omp', providerHandleChain: [], accountHome }
+}
+
+function resolver(
+  record: AgentSessionRecord,
+  options: {
+    launchEnv?: Record<string, string>
+    fullAccess?: boolean
+    probeVersion?: AcpStructuredLaunchResolverDeps['probeVersion']
+  } = {}
+) {
+  return createAcpStructuredLaunchResolver(OMP, {
+    store: { getRecord: () => record },
+    readJournal: () => null,
+    resolveWorkspacePath: async () => '/repo/worktree',
+    resolveEnvironment: async () => ({ PATH: '/usr/bin', HOME: '/home/user' }),
+    resolveLaunchEnv: () => options.launchEnv ?? {},
+    resolveFullAccess: () => options.fullAccess ?? false,
+    resolveCommand: (command) => `/resolved/${command}`,
+    inheritedEnv: {},
+    probeVersion: options.probeVersion ?? (async (_input, supports) => supports('17.0.5'))
+  })
+}
+
+describe('OMP ACP launch resolution', () => {
+  it('runs `omp acp` pointed at the agent directory the chat pinned, with or without full access', async () => {
+    for (const fullAccess of [false, true]) {
+      const launch = await resolver(ompRecord(), { fullAccess })({ identity })
+      expect(launch).toMatchObject({ command: '/resolved/omp', args: ['acp'], fullAccess })
+      expect(launch.env.PI_CODING_AGENT_DIR).toBe('/home/user/.omp/agent')
+    }
+  })
+
+  it("passes the user's own OMP environment through unchanged", async () => {
+    const userEnv = {
+      OMP_PROFILE: 'work',
+      PI_CONFIG_DIR: 'relative/config',
+      PI_SMOL_MODEL: 'fast',
+      ANTHROPIC_API_KEY: 'sk-test'
+    }
+    const launch = await resolver(ompRecord(), { launchEnv: userEnv })({ identity })
+    expect(launch.envToDelete).toEqual([])
+    const child = createProviderSpawnSpec(
+      {
+        command: launch.command,
+        args: launch.args,
+        env: launch.env,
+        envToDelete: [...ACP_CHILD_ENV_TO_DELETE, ...launch.envToDelete]
+      },
+      { ORCA_PANE_KEY: 'tab-1:pane-1' },
+      'darwin'
+    ).env
+    expect(child).toMatchObject(userEnv)
+    // A pane's identity would let OMP's Orca status extension report for this chat too.
+    expect(child.ORCA_PANE_KEY).toBeUndefined()
+  })
+
+  it('keeps a chat on the directory it pinned when the launch env names another', async () => {
+    const launch = await resolver(ompRecord(), {
+      launchEnv: { PI_CODING_AGENT_DIR: '/data/other-agent' }
+    })({ identity })
+    expect(launch.env.PI_CODING_AGENT_DIR).toBe('/home/user/.omp/agent')
+  })
+
+  it("refuses a record that pins another agent's directory", async () => {
+    await expect(
+      resolver(ompRecord({ variable: 'GROK_HOME', path: '/home/user/.grok' }))({ identity })
+    ).rejects.toThrow(/pin PI_CODING_AGENT_DIR/)
+  })
+
+  it.each(['17.0.5', '17.2.12', '18.4.5'])('admits OMP %s', async (version) => {
+    const launch = resolver(ompRecord(), {
+      probeVersion: async (_input, supports) => supports(version)
+    })
+    await expect(launch({ identity })).resolves.toMatchObject({ args: ['acp'] })
+  })
+
+  it.each(['17.0.4', '16.9.0', '18.0.0-beta.1'])(
+    'refuses OMP %s before spawning it, as a host that cannot run the chat',
+    async (version) => {
+      const launch = resolver(ompRecord(), {
+        probeVersion: async (_input, supports) => supports(version)
+      })
+      await expect(launch({ identity })).rejects.toMatchObject({
+        refusal: {
+          code: 'structured_agent_session_unsupported',
+          details: { reason: 'hostUnsupported' }
+        }
+      })
+    }
+  )
+
+  it('refuses when the version cannot be read', async () => {
+    const launch = resolver(ompRecord(), { probeVersion: async () => false })
+    await expect(launch({ identity })).rejects.toMatchObject({
+      refusal: { code: 'structured_agent_session_unsupported' }
+    })
+  })
+
+  it('asks the version of exactly the binary, folder and environment it spawns', async () => {
+    const asked: Parameters<NonNullable<AcpStructuredLaunchResolverDeps['probeVersion']>>[0][] = []
+    const launch = await resolver(ompRecord(), {
+      probeVersion: async (input, supports) => (asked.push(input), supports('17.0.5'))
+    })({ identity })
+    expect(asked).toEqual([{ program: launch.command, cwd: launch.cwd, env: launch.env }])
+  })
+})
diff --git a/src/main/acp/acp-structured-omp-recordings.test.ts b/src/main/acp/acp-structured-omp-recordings.test.ts
new file mode 100644
index 000000000000..4c0dc40c03d6
--- /dev/null
+++ b/src/main/acp/acp-structured-omp-recordings.test.ts
@@ -0,0 +1,117 @@
+// The adapter against OMP's recorded `omp acp` traffic (17.0.5): each recording plays back as the
+// agent, and the assertions read the journal a client would see.
+
+import { afterEach, describe, expect, it } from 'vitest'
+import type { AgentJournalMessageItem } from '../../shared/agent-session-journal-types'
+import { readAgentJournalTurn } from '../../shared/agent-session-turn-record'
+import {
+  closeProviderTimelineRigs,
+  SESSION
+} from '../native-chat/agent-session-timeline/provider-timeline-assembler-test-support'
+import { acpLaunchSpecFor } from './acp-launch-specs'
+import {
+  openAcpAdapterRig,
+  waitFor,
+  type AcpAdapterRig
+} from './acp-structured-adapter.test-support'
+import { GrokFixtureReplay } from './acp-structured-fixture-replay.test-support'
+import { readAcpFixture } from './acp-timeline-fixture.test-support'
+
+afterEach(async () => {
+  await closeProviderTimelineRigs()
+})
+
+const ask: AgentJournalMessageItem = {
+  kind: 'message',
+  role: 'user',
+  blocks: [{ type: 'text', text: 'Fixture prompt' }]
+}
+
+async function replaying(name: string) {
+  const replay = new GrokFixtureReplay(await readAcpFixture(name))
+  const rig = await openAcpAdapterRig({
+    spec: acpLaunchSpecFor('omp')!,
+    script: (scripted) => replay.attach(scripted)
+  })
+  await rig.acquire()
+  await rig.adapter.dispatch({ sessionId: SESSION, clientMessageId: 'send-1', body: ask, fence: 1 })
+  return { rig, replay }
+}
+
+async function turns(rig: AcpAdapterRig) {
+  return (await rig.rig.rows()).flatMap((row) => readAgentJournalTurn(row.body) ?? [])
+}
+
+async function toolRow(rig: AcpAdapterRig) {
+  const rows = (await rig.rig.rows()).filter((row) => row.body.kind === 'tool-call')
+  expect(rows).toHaveLength(1)
+  return rows[0]!.body
+}
+
+async function allowOnce(rig: AcpAdapterRig, replay: GrokFixtureReplay) {
+  const approval = await waitFor(async () => {
+    const found = (await rig.rig.rows()).find((row) => row.body.kind === 'approval')
+    if (!found || replay.awaiting !== 'reply') {
+      throw new Error('no pending approval yet')
+    }
+    return found
+  })
+  await rig.adapter.answerPrompt({
+    sessionId: SESSION,
+    itemId: approval.itemId,
+    kind: 'approval',
+    response: { kind: 'option', optionId: 'allow_once' },
+    fence: 1,
+    commit: async () => {}
+  })
+}
+
+describe('OMP recordings through the adapter', () => {
+  it("a failed command's row shows its output and exit code, not the command again", async () => {
+    const { rig, replay } = await replaying('omp-v17-shell-exit-3')
+    await allowOnce(rig, replay)
+    await waitFor(() => expect(replay.awaiting).toBeNull())
+    await waitFor(async () =>
+      expect(await turns(rig)).toMatchObject([{ state: 'completed', outcome: 'success' }])
+    )
+    expect(await toolRow(rig)).toMatchObject({
+      state: 'failed',
+      input: { command: 'printf hi; exit 3' },
+      exitCode: 3,
+      output: { head: 'hi', truncated: false }
+    })
+  })
+
+  it("a successful command's row shows its output", async () => {
+    const { rig, replay } = await replaying('omp-v17-shell-ok')
+    await allowOnce(rig, replay)
+    await waitFor(() => expect(replay.awaiting).toBeNull())
+    await waitFor(async () =>
+      expect(await turns(rig)).toMatchObject([{ state: 'completed', outcome: 'success' }])
+    )
+    const tool = await toolRow(rig)
+    expect(tool).toMatchObject({ state: 'completed', output: { head: 'ok', truncated: false } })
+    // OMP reports an exit code only when it is not zero.
+    expect(tool).not.toHaveProperty('exitCode')
+  })
+
+  it('Stop during a running command ends the turn and leaves the row without the command as output', async () => {
+    const { rig, replay } = await replaying('omp-v17-stop-mid-tool')
+    await allowOnce(rig, replay)
+    await waitFor(() => expect(replay.awaiting).toBe('session/cancel'))
+    await expect(rig.adapter.cancelTurn({ sessionId: SESSION, fence: 1 })).resolves.toEqual({
+      cancelled: true
+    })
+    await waitFor(() => expect(replay.awaiting).toBeNull())
+    await waitFor(async () =>
+      expect(await turns(rig)).toMatchObject([{ state: 'interrupted', outcome: 'cancellation' }])
+    )
+    // OMP sends nothing more for the stopped command; Orca settles its row with the turn.
+    const tool = await toolRow(rig)
+    expect(tool).toMatchObject({
+      endedAs: 'interrupted',
+      input: { command: 'sleep 30', timeout: 60 }
+    })
+    expect(tool).not.toHaveProperty('output')
+  })
+})
diff --git a/src/main/acp/fixtures/omp-v17-shell-exit-3.jsonl b/src/main/acp/fixtures/omp-v17-shell-exit-3.jsonl
new file mode 100644
index 000000000000..7bbad57dbe8a
--- /dev/null
+++ b/src/main/acp/fixtures/omp-v17-shell-exit-3.jsonl
@@ -0,0 +1,23 @@
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","id":3,"method":"session/prompt","params":{"sessionId":"session-1","prompt":[{"type":"text","text":"Use the bash tool exactly once to run this exact command and nothing else: printf hi; exit 3\nDo not run any other tool. Then reply in one short sentence with what it printed and its exit code."}]}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"available_commands_update","availableCommands":[{"name":"model","description":"Show current model selection"},{"name":"fast","description":"Toggle fast mode","input":{"hint":"[on|off|status]"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"session_info_update","updatedAt":"2026-10-08T03:24:13.994Z"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","id":0,"method":"session/request_permission","params":{"sessionId":"session-1","toolCall":{"toolCallId":"call-1","title":"printf hi; exit 3","kind":"execute","status":"pending","rawInput":{"command":"printf hi; exit 3","timeout":10},"content":[{"type":"content","content":{"type":"text","text":"$ printf hi; exit 3"}}],"locations":[]},"options":[{"optionId":"allow_once","name":"Allow once","kind":"allow_once"},{"optionId":"allow_always","name":"Always allow","kind":"allow_always"},{"optionId":"reject_once","name":"Reject","kind":"reject_once"},{"optionId":"reject_always","name":"Always reject","kind":"reject_always"}]}}}
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","id":0,"result":{"outcome":{"outcome":"selected","optionId":"allow_once"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call","toolCallId":"call-1","title":"$ printf hi; exit 3","kind":"execute","status":"pending","rawInput":{"command":"printf hi; exit 3","timeout":10},"content":[{"type":"content","content":{"type":"text","text":"$ printf hi; exit 3"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call_update","toolCallId":"call-1","status":"in_progress","rawOutput":{"content":[{"type":"text","text":"hi"}],"details":{}},"content":[{"type":"content","content":{"type":"text","text":"$ printf hi; exit 3"}},{"type":"content","content":{"type":"text","text":"hi"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call_update","toolCallId":"call-1","status":"failed","rawOutput":{"content":[{"type":"text","text":"hi\n\nWall time: 0.09 seconds\n\nCommand exited with code 3"}],"details":{"timeoutSeconds":10,"wallTimeMs":87.65562499999942,"exitCode":3},"isError":true},"content":[{"type":"content","content":{"type":"text","text":"$ printf hi; exit 3"}},{"type":"content","content":{"type":"text","text":"hi\n\nWall time: 0.09 seconds\n\nCommand exited with code 3"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"It"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" printed"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" `"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"hi"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"`"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" and"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" exited"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" with"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" code"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" "},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"3"},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"."},"messageId":"94959649-0666-4fe3-b0f8-5f4254d56d7e"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"usage_update","size":272000,"used":18220,"cost":{"amount":0.10272500000000001,"currency":"USD"}}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"session_info_update","updatedAt":"2026-10-08T03:24:19.387Z"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","id":3,"result":{"stopReason":"end_turn","usage":{"inputTokens":18459,"outputTokens":49,"totalTokens":36428,"cachedReadTokens":17920}}}}
diff --git a/src/main/acp/fixtures/omp-v17-shell-ok.jsonl b/src/main/acp/fixtures/omp-v17-shell-ok.jsonl
new file mode 100644
index 000000000000..0c96d48be96e
--- /dev/null
+++ b/src/main/acp/fixtures/omp-v17-shell-ok.jsonl
@@ -0,0 +1,23 @@
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","id":3,"method":"session/prompt","params":{"sessionId":"session-1","prompt":[{"type":"text","text":"Use the bash tool exactly once to run this exact command and nothing else: printf ok\nDo not run any other tool. Then reply in one short sentence with what it printed and its exit code."}]}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"available_commands_update","availableCommands":[{"name":"model","description":"Show current model selection"},{"name":"fast","description":"Toggle fast mode","input":{"hint":"[on|off|status]"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"session_info_update","updatedAt":"2026-10-08T03:24:00.014Z"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","id":0,"method":"session/request_permission","params":{"sessionId":"session-1","toolCall":{"toolCallId":"call-1","title":"printf ok","kind":"execute","status":"pending","rawInput":{"command":"printf ok"},"content":[{"type":"content","content":{"type":"text","text":"$ printf ok"}}],"locations":[]},"options":[{"optionId":"allow_once","name":"Allow once","kind":"allow_once"},{"optionId":"allow_always","name":"Always allow","kind":"allow_always"},{"optionId":"reject_once","name":"Reject","kind":"reject_once"},{"optionId":"reject_always","name":"Always reject","kind":"reject_always"}]}}}
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","id":0,"result":{"outcome":{"outcome":"selected","optionId":"allow_once"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call","toolCallId":"call-1","title":"$ printf ok","kind":"execute","status":"pending","rawInput":{"command":"printf ok"},"content":[{"type":"content","content":{"type":"text","text":"$ printf ok"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call_update","toolCallId":"call-1","status":"in_progress","rawOutput":{"content":[{"type":"text","text":"ok"}],"details":{}},"content":[{"type":"content","content":{"type":"text","text":"$ printf ok"}},{"type":"content","content":{"type":"text","text":"ok"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call_update","toolCallId":"call-1","status":"completed","rawOutput":{"content":[{"type":"text","text":"ok\n\nWall time: 0.41 seconds"}],"details":{"timeoutSeconds":300,"wallTimeMs":406.50874999999996}},"content":[{"type":"content","content":{"type":"text","text":"$ printf ok"}},{"type":"content","content":{"type":"text","text":"ok\n\nWall time: 0.41 seconds"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"It"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" printed"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" `"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"ok"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"`"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" and"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" exited"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" with"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" code"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":" "},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"0"},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"."},"messageId":"62df7016-80a7-41a9-8467-43c45abf950b"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"usage_update","size":272000,"used":18198,"cost":{"amount":0.10234000000000001,"currency":"USD"}}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"session_info_update","updatedAt":"2026-10-08T03:24:06.553Z"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","id":3,"result":{"stopReason":"end_turn","usage":{"inputTokens":18430,"outputTokens":41,"totalTokens":36391,"cachedReadTokens":17920}}}}
diff --git a/src/main/acp/fixtures/omp-v17-stop-mid-tool.jsonl b/src/main/acp/fixtures/omp-v17-stop-mid-tool.jsonl
new file mode 100644
index 000000000000..660483571a23
--- /dev/null
+++ b/src/main/acp/fixtures/omp-v17-stop-mid-tool.jsonl
@@ -0,0 +1,8 @@
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","id":3,"method":"session/prompt","params":{"sessionId":"session-1","prompt":[{"type":"text","text":"Use the bash tool exactly once to run this exact command and nothing else: sleep 30\nDo not run any other tool. Then reply in one short sentence with what it printed and its exit code."}]}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"available_commands_update","availableCommands":[{"name":"model","description":"Show current model selection"},{"name":"fast","description":"Toggle fast mode","input":{"hint":"[on|off|status]"}}]}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"session_info_update","updatedAt":"2026-10-08T03:32:42.139Z"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","id":0,"method":"session/request_permission","params":{"sessionId":"session-1","toolCall":{"toolCallId":"call-1","title":"sleep 30","kind":"execute","status":"pending","rawInput":{"command":"sleep 30","timeout":60},"content":[{"type":"content","content":{"type":"text","text":"$ sleep 30"}}],"locations":[]},"options":[{"optionId":"allow_once","name":"Allow once","kind":"allow_once"},{"optionId":"allow_always","name":"Always allow","kind":"allow_always"},{"optionId":"reject_once","name":"Reject","kind":"reject_once"},{"optionId":"reject_always","name":"Always reject","kind":"reject_always"}]}}}
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","id":0,"result":{"outcome":{"outcome":"selected","optionId":"allow_once"}}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"session-1","update":{"sessionUpdate":"tool_call","toolCallId":"call-1","title":"$ sleep 30","kind":"execute","status":"pending","rawInput":{"command":"sleep 30","timeout":60},"content":[{"type":"content","content":{"type":"text","text":"$ sleep 30"}}]}}}}
+{"direction":"out","process":"p1","message":{"jsonrpc":"2.0","method":"session/cancel","params":{"sessionId":"session-1"}}}
+{"direction":"in","process":"p1","message":{"jsonrpc":"2.0","id":3,"result":{"stopReason":"cancelled","usage":{"inputTokens":234,"outputTokens":63,"totalTokens":18217,"cachedReadTokens":17920}}}}
diff --git a/src/main/agent-cli-version-probe.test.ts b/src/main/agent-cli-version-probe.test.ts
index 33d9537dd4f0..d04480f71dce 100644
--- a/src/main/agent-cli-version-probe.test.ts
+++ b/src/main/agent-cli-version-probe.test.ts
@@ -1,5 +1,9 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest'
-import { isStableCliVersionOnLine, probeAgentCliVersion } from './agent-cli-version-probe'
+import {
+  isStableCliVersionFrom,
+  isStableCliVersionOnLine,
+  probeAgentCliVersion
+} from './agent-cli-version-probe'
 
 const { runProcess } = vi.hoisted(() => ({ runProcess: vi.fn() }))
 vi.mock('../shared/child-process/run-process', () => ({ runProcess }))
@@ -42,6 +46,13 @@ describe('probeAgentCliVersion', () => {
     expect(seen).toEqual(['2.0.21'])
   })
 
+  it('reads a version printed after the program name and a slash', async () => {
+    prints('omp/17.0.5\n')
+    const seen: string[] = []
+    await probeAgentCliVersion(INPUT, (version) => (seen.push(version), true))
+    expect(seen).toEqual(['17.0.5'])
+  })
+
   it.each([
     ['a non-zero exit', { code: 1 }],
     ['a timeout', { timedOut: true }],
@@ -92,3 +103,16 @@ describe('isStableCliVersionOnLine', () => {
     expect(isStableCliVersionOnLine(version, line)).toBe(supported)
   })
 })
+
+describe('isStableCliVersionFrom', () => {
+  it.each([
+    ['17.0.5', true],
+    ['17.2.12', true],
+    ['18.4.5', true],
+    ['17.0.4', false],
+    ['16.9.0', false],
+    ['18.0.0-beta.1', false]
+  ])('%s -> %s', (version, supported) => {
+    expect(isStableCliVersionFrom(version, '17.0.5')).toBe(supported)
+  })
+})
diff --git a/src/main/agent-cli-version-probe.ts b/src/main/agent-cli-version-probe.ts
index b5f2a312a780..4cf45ce0e4d2 100644
--- a/src/main/agent-cli-version-probe.ts
+++ b/src/main/agent-cli-version-probe.ts
@@ -53,14 +53,15 @@ export async function probeAgentCliVersion(
   return true
 }
 
+/** A stable release at or after `floor`, on any later major line too. */
+export function isStableCliVersionFrom(version: string, floor: string): boolean {
+  return !isPrereleaseAppVersion(version) && hasReachedAppVersion(version, floor)
+}
+
 /** A stable release on `major`'s line, at or after `floor`. */
 export function isStableCliVersionOnLine(
   version: string,
   line: { major: number; floor: string }
 ): boolean {
-  return (
-    version.startsWith(`${line.major}.`) &&
-    !isPrereleaseAppVersion(version) &&
-    hasReachedAppVersion(version, line.floor)
-  )
+  return version.startsWith(`${line.major}.`) && isStableCliVersionFrom(version, line.floor)
 }
diff --git a/src/main/runtime/structured-agent-launch-support-probe-omp.test.ts b/src/main/runtime/structured-agent-launch-support-probe-omp.test.ts
new file mode 100644
index 000000000000..393f0158594e
--- /dev/null
+++ b/src/main/runtime/structured-agent-launch-support-probe-omp.test.ts
@@ -0,0 +1,123 @@
+import { chmod, mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import type { GlobalSettings } from '../../shared/global-settings-types'
+import { agentSessionRecordFixture } from '../../shared/agent-session-record.test-fixture'
+import { acpLaunchSpecFor } from '../acp/acp-launch-specs'
+import { createAcpStructuredLaunchResolver } from '../acp/acp-structured-launch-resolution'
+import { structuredAgentSupportsLaunch } from './structured-agent-launch-support'
+
+const { loginShell } = vi.hoisted(() => {
+  const loginShell: { env: Record<string, string> } = { env: {} }
+  return { loginShell }
+})
+vi.mock('../startup/login-shell-environment', () => ({
+  resolveLoginShellEnvironment: async () => loginShell.env
+}))
+
+type Settings = Pick<
+  GlobalSettings,
+  'agentDefaultEnv' | 'nativeChatInheritShellEnvironment' | 'nativeChatShellEnvironmentVariables'
+> &
+  Partial<Pick<GlobalSettings, 'agentCmdOverrides'>>
+
+let root: string
+let shellBin: string
+let privateBin: string
+
+/** A stand-in `omp` that answers `--version` as OMP does; never the real agent CLI. */
+async function fakeOmp(dir: string, version: string): Promise<string> {
+  await mkdir(dir, { recursive: true })
+  const file = join(dir, 'omp')
+  await writeFile(file, `#!/bin/sh\necho omp/${version}\n`)
+  await chmod(file, 0o755)
+  return dir
+}
+
+function runtimeWith(settings: Settings) {
+  return {
+    requireStore: () => ({ getSettings: () => settings }),
+    resolveRuntimeFileTarget: async () => ({ worktree: { path: root } })
+  }
+}
+
+function launchWith(settings: Settings) {
+  return createAcpStructuredLaunchResolver(acpLaunchSpecFor('omp')!, {
+    store: {
+      getRecord: () => ({
+        ...agentSessionRecordFixture(),
+        provider: 'omp',
+        providerHandleChain: [],
+        accountHome: { variable: 'PI_CODING_AGENT_DIR', path: join(root, '.omp', 'agent') }
+      })
+    },
+    readJournal: () => null,
+    resolveWorkspacePath: async () => root,
+    resolveEnvironment: async () => loginShell.env,
+    resolveLaunchEnv: () => settings.agentDefaultEnv?.omp ?? {},
+    resolveCommandSettings: () => settings,
+    inheritedEnv: {}
+  })({
+    identity: {
+      sessionId: 'session-alpha-1',
+      workspaceId: 'workspace-1',
+      hostId: 'local',
+      agent: 'omp',
+      providerHandle: null
+    }
+  })
+}
+
+beforeEach(async () => {
+  root = await mkdtemp(join(tmpdir(), 'orca-omp-probe-'))
+  shellBin = await fakeOmp(join(root, 'shell-bin'), '16.2.0')
+  privateBin = await fakeOmp(join(root, 'omp-prefix', 'bin'), '17.0.5')
+  // Orca's resolved login-shell PATH, with an OMP older than ACP support first.
+  loginShell.env = { PATH: `${shellBin}:/usr/bin:/bin`, HOME: root }
+})
+afterEach(async () => {
+  await rm(root, { recursive: true, force: true })
+})
+
+const base = { nativeChatInheritShellEnvironment: true, nativeChatShellEnvironmentVariables: [] }
+
+// Real `--version` runs against stand-in scripts: the whole create check, not a mocked probe.
+describe.skipIf(process.platform === 'win32')('OMP create check and launch, real probe', () => {
+  it('checks and launches the binary the Command setting names', async () => {
+    const settings = {
+      ...base,
+      agentDefaultEnv: {},
+      agentCmdOverrides: { omp: join(privateBin, 'omp') }
+    }
+    expect(await structuredAgentSupportsLaunch('omp', 'id:w', runtimeWith(settings))).toBe(true)
+    const launch = await launchWith(settings)
+    expect(launch.command).toBe(join(privateBin, 'omp'))
+    expect(launch.args).toEqual(['acp'])
+  })
+
+  it('asks the OMP the per-agent PATH names, not the one first on the shell PATH', async () => {
+    const settings = { ...base, agentDefaultEnv: { omp: { PATH: `${privateBin}:/usr/bin:/bin` } } }
+    expect(await structuredAgentSupportsLaunch('omp', 'id:w', runtimeWith(settings))).toBe(true)
+    expect((await launchWith(settings)).command).toBe(join(privateBin, 'omp'))
+  })
+
+  it('keeps an OMP older than 17.0.5 on its terminal-backed chat', async () => {
+    const settings = { ...base, agentDefaultEnv: {} }
+    expect(await structuredAgentSupportsLaunch('omp', 'id:w', runtimeWith(settings))).toBe(false)
+  })
+
+  it('refuses the launch with the setting named when the Command is not runnable', async () => {
+    const settings = {
+      ...base,
+      agentDefaultEnv: {},
+      agentCmdOverrides: { omp: join(root, 'missing', 'omp') }
+    }
+    // Admitted, so the chat states why rather than silently opening a terminal.
+    expect(await structuredAgentSupportsLaunch('omp', 'id:w', runtimeWith(settings))).toBe(true)
+    await expect(launchWith(settings)).rejects.toMatchObject({
+      name: 'AgentSessionPreSpawnError',
+      reason: 'agentCommandNotRunnable'
+    })
+  })
+})
diff --git a/src/main/runtime/structured-agent-runtime-registrations-acp.test.ts b/src/main/runtime/structured-agent-runtime-registrations-acp.test.ts
index ffc1920eba07..51efbacb1247 100644
--- a/src/main/runtime/structured-agent-runtime-registrations-acp.test.ts
+++ b/src/main/runtime/structured-agent-runtime-registrations-acp.test.ts
@@ -4,12 +4,13 @@ import {
   structuredAgentRuntimeRegistration,
   type StructuredAgentAccountHomeServices
 } from './structured-agent-runtime-registrations'
+import { decideAgentLaunchMode } from '../agent-launch/agent-launch-mode'
 
 describe('ACP agents in the runtime registrations', () => {
   it('registers Grok beside Claude and Codex with its declared capabilities', () => {
     expect(
       STRUCTURED_AGENT_RUNTIME_REGISTRATIONS.map(({ definition }) => definition.agent)
-    ).toEqual(['pi', 'codex', 'claude', 'grok', 'opencode'])
+    ).toEqual(['pi', 'codex', 'claude', 'grok', 'opencode', 'omp'])
     expect(structuredAgentRuntimeRegistration('grok')?.definition).toMatchObject({
       handleTransport: 'acp',
       accountHomeVariable: 'GROK_HOME',
@@ -43,6 +44,58 @@ describe('ACP agents in the runtime registrations', () => {
     expect(structuredAgentRuntimeRegistration('grok')?.supportsLaunch).toBeUndefined()
   })
 
+  it('registers OMP on the ACP lane pinning its agent directory, asking its version at create', () => {
+    const registration = structuredAgentRuntimeRegistration('omp')
+    expect(registration?.definition).toMatchObject({
+      agent: 'omp',
+      handleTransport: 'acp',
+      accountHomeVariable: 'PI_CODING_AGENT_DIR',
+      capabilities: { imagePrompts: false, steering: 'queue', approvalEnforcement: 'orca' }
+    })
+    expect(registration?.supportsLaunch).toBeTypeOf('function')
+  })
+
+  it('opens OMP as a structured chat only with the updated structured chat setting on', () => {
+    const settings = {
+      experimentalNativeChat: true,
+      openAgentTabsInChatByDefault: true,
+      experimentalStructuredNativeChat: true
+    }
+    const placement = { agent: 'omp', workspaceKind: 'git-worktree' } as const
+    expect(decideAgentLaunchMode({ placement, settings }).mode).toBe('structured')
+    // Off: OMP keeps the terminal-backed chat it has always had.
+    expect(
+      decideAgentLaunchMode({
+        placement,
+        settings: { ...settings, experimentalStructuredNativeChat: false }
+      })
+    ).toMatchObject({ mode: 'terminal', reason: 'user_default' })
+  })
+
+  it("finds OMP's agent directory from the launch env, else OMP's default", async () => {
+    const { resolveAccountHome } = structuredAgentRuntimeRegistration('omp')!
+    const unused = (): never => {
+      throw new Error('OMP resolves its account home without the runtime')
+    }
+    const resolve = async (launchEnv: NodeJS.ProcessEnv) =>
+      resolveAccountHome(
+        { launchEnv, location: null, purpose: 'read', workspacePath: null },
+        {
+          getClaudeConfigDirectory: unused,
+          prepareCodexLaunchHome: unused,
+          readCodexLaunchHome: unused,
+          workspaceTrustSettings: unused
+        }
+      )
+    await expect(resolve({ PI_CODING_AGENT_DIR: '/data/omp-agent' })).resolves.toEqual({
+      variable: 'PI_CODING_AGENT_DIR',
+      path: '/data/omp-agent'
+    })
+    await expect(resolve({ PI_CODING_AGENT_DIR: '' })).resolves.toMatchObject({
+      path: expect.stringMatching(/[\\/]\.omp[\\/]agent$/)
+    })
+  })
+
   it('takes model and effort picks at rest, and keeps no model list of its own', () => {
     const resting = structuredAgentRuntimeRegistration('grok')!.definition.restingOptions
     expect(['model', 'effort'].map(resting.acceptsKey)).toEqual([true, true])