diff --git a/src/main/opencode/opencode-pty-launch.ts b/src/main/opencode/opencode-pty-launch.ts
index 3a547d35c0e..53c0e43ff88 100644
--- a/src/main/opencode/opencode-pty-launch.ts
+++ b/src/main/opencode/opencode-pty-launch.ts
@@ -91,7 +91,7 @@ export async function prepareOpenCodePtyLaunch(options: {
     const last = parsed.ok ? parsed.tokens.length - 1 : -1
     if (
       parsed.ok &&
-      !isOpenCodeRunCommand(parsed.tokens) &&
+      !isOpenCodeRunCommand(parsed.tokens, shell) &&
       parsed.tokens.filter((token) => token === '--prompt').length === 1 &&
       parsed.tokens[last - 1] === '--prompt' &&
       parsed.tokens[last] === body &&
diff --git a/src/shared/flag-prompt-startup.ts b/src/shared/flag-prompt-startup.ts
index 28dd70cf0bd..50e1be306fa 100644
--- a/src/shared/flag-prompt-startup.ts
+++ b/src/shared/flag-prompt-startup.ts
@@ -4,7 +4,7 @@ import type { SessionOptionValue } from './native-chat-session-options'
 import type { TuiAgent } from './tui-agent'
 import { TUI_AGENT_CONFIG } from './tui-agent-config'
 import { tokenizeStartupCommand, type AgentStartupShell } from './tui-agent-startup-shell'
-import { isOpenCodeRunCommand } from './opencode-headless-command'
+import { findOpenCodeRunCommand } from './opencode-headless-command'
 import { openCodeStartupPromptEnv } from './opencode-startup-prompt'
 
 export function appliedSessionOptionProps(values: Record<string, SessionOptionValue>) {
@@ -22,13 +22,13 @@ export function buildFlagPromptStartupPlan(args: {
   agentEnv: Record<string, string> | null | undefined
 }): AgentStartupPlan {
   const parsed = tokenizeStartupCommand(args.launchCommand, args.shell)
-  const isOpenCodeRun =
-    (args.agent === 'opencode' || args.agent === 'opencode2') &&
-    parsed.ok &&
-    isOpenCodeRunCommand(parsed.tokens)
+  const openCodeRun =
+    (args.agent === 'opencode' || args.agent === 'opencode2') && parsed.ok
+      ? findOpenCodeRunCommand(parsed.tokens, args.shell)
+      : null
   // OpenCode run takes a positional message; --prompt belongs to its TUI.
-  const promptSuffix = isOpenCodeRun
-    ? parsed.tokens.includes('--')
+  const promptSuffix = openCodeRun
+    ? openCodeRun.messageSeparatorIndex !== null
       ? ` ${args.quotedPrompt}`
       : ` -- ${args.quotedPrompt}`
     : ` --prompt ${args.quotedPrompt}`
diff --git a/src/shared/opencode-headless-command.test.ts b/src/shared/opencode-headless-command.test.ts
index 408895a1dbb..cc240be7f9c 100644
--- a/src/shared/opencode-headless-command.test.ts
+++ b/src/shared/opencode-headless-command.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, it } from 'vitest'
+import { tokenizeStartupCommand } from './tui-agent-startup-shell'
 import { tokenizeCommandLine } from './agent-command-line-entrypoint'
 import { isOpenCodeRunCommand } from './opencode-headless-command'
 
@@ -24,3 +25,32 @@ describe('isOpenCodeRunCommand', () => {
     expect(matches('opencode --log-level run')).toBe(false)
   })
 })
+
+describe('wrapped OpenCode run command position', () => {
+  it.each([
+    'CUSTOM_CONFIG=private opencode --log-level debug run --standalone',
+    'env CUSTOM_CONFIG=private opencode run --standalone',
+    'CUSTOM_CONFIG=private /usr/bin/env -- EXTRA_CONFIG=kept opencode run --standalone'
+  ])('recognizes only the executable behind supported POSIX prefixes: %s', (command) => {
+    expect(matches(command)).toBe(true)
+  })
+
+  it('recognizes a PowerShell call operator before a quoted executable', () => {
+    const parsed = tokenizeStartupCommand(
+      '& "C:\\Program Files\\opencode\\opencode.exe" run --standalone',
+      'powershell'
+    )
+    expect(parsed.ok).toBe(true)
+    if (!parsed.ok) throw new Error(parsed.error)
+    expect(isOpenCodeRunCommand(parsed.tokens, 'powershell')).toBe(true)
+    expect(isOpenCodeRunCommand(parsed.tokens, 'cmd')).toBe(false)
+  })
+
+  it('does not find executable names inside other commands or prompt arguments', () => {
+    expect(matches('env CUSTOM_CONFIG=private echo opencode run')).toBe(false)
+    expect(matches('env CUSTOM_CONFIG=private echo run')).toBe(false)
+    expect(matches('CUSTOM_CONFIG=private opencode --prompt "opencode run"')).toBe(false)
+    expect(matches('env -- opencode serve --title run')).toBe(false)
+    expect(matches('opencode attach http://host/run')).toBe(false)
+  })
+})
diff --git a/src/shared/opencode-headless-command.ts b/src/shared/opencode-headless-command.ts
index 5328f7931fc..858fb965125 100644
--- a/src/shared/opencode-headless-command.ts
+++ b/src/shared/opencode-headless-command.ts
@@ -1,16 +1,82 @@
-// Why: `opencode run` answers one prompt and exits, so its process lifetime is its turn.
-// Not in agent-headless-command's table: that would also drop OpenCode 1 `run`'s identity,
-// whose in-process plugin reports it. Only `--log-level` takes a separate value before the
-// subcommand; any other valued option makes the value the first positional, which fails safe.
-export function isOpenCodeRunCommand(tokens: readonly string[]): boolean {
-  for (let index = 1; index < tokens.length; index += 1) {
+import { extractLeadingEnvAssignments } from './command-environment'
+import { getCommandTokenPathBasename } from './command-token-scanner'
+import type { AgentStartupShell } from './tui-agent-startup-shell'
+
+const RUN_VALUE_FLAGS = new Set([
+  '--log-level',
+  '--completions',
+  '--server',
+  '--session',
+  '-s',
+  '--model',
+  '-m',
+  '--agent',
+  '--format',
+  '--file',
+  '-f',
+  '--title'
+])
+
+function openCodeCommandPosition(tokens: readonly string[], shell: AgentStartupShell): number {
+  if (shell === 'powershell' && tokens[0] === '&') {
+    return 1
+  }
+  if (shell !== 'posix') {
+    return 0
+  }
+  let index = tokens.length - extractLeadingEnvAssignments(tokens.slice()).rest.length
+  if (getCommandTokenPathBasename(tokens[index] ?? '') === 'env') {
+    index += 1
+    if (tokens[index] === '--') {
+      index += 1
+    }
+    index = tokens.length - extractLeadingEnvAssignments(tokens.slice(index)).rest.length
+  }
+  return index
+}
+
+export function findOpenCodeRunCommand(
+  tokens: readonly string[],
+  shell: AgentStartupShell = 'posix'
+): { runIndex: number; messageSeparatorIndex: number | null } | null {
+  const commandPosition = openCodeCommandPosition(tokens, shell)
+  if (commandPosition > 0) {
+    const binary = getCommandTokenPathBasename(tokens[commandPosition] ?? '')
+      .toLowerCase()
+      .replace(/\.(?:exe|cmd)$/, '')
+    if (binary !== 'opencode' && binary !== 'opencode2') {
+      return null
+    }
+  }
+  for (let index = commandPosition + 1; index < tokens.length; index += 1) {
     const token = tokens[index]
     if (!token.startsWith('-')) {
-      return token === 'run'
+      if (token !== 'run') {
+        return null
+      }
+      for (let argumentIndex = index + 1; argumentIndex < tokens.length; argumentIndex += 1) {
+        const argument = tokens[argumentIndex]
+        if (argument === '--') {
+          return { runIndex: index, messageSeparatorIndex: argumentIndex }
+        }
+        if (RUN_VALUE_FLAGS.has(argument)) {
+          argumentIndex += 1
+        }
+      }
+      return { runIndex: index, messageSeparatorIndex: null }
     }
+    // Other valued global options fail closed at their first positional value.
     if (token === '--log-level') {
       index += 1
     }
   }
-  return false
+  return null
+}
+
+// OpenCode run's process lifetime is its turn; v1 still reports through its plugin.
+export function isOpenCodeRunCommand(
+  tokens: readonly string[],
+  shell: AgentStartupShell = 'posix'
+): boolean {
+  return findOpenCodeRunCommand(tokens, shell) !== null
 }
diff --git a/src/shared/opencode-startup-prompt.test.ts b/src/shared/opencode-startup-prompt.test.ts
index d438028ba96..e82b46f8e77 100644
--- a/src/shared/opencode-startup-prompt.test.ts
+++ b/src/shared/opencode-startup-prompt.test.ts
@@ -105,3 +105,55 @@ describe('native OpenCode startup submission intent', () => {
     ).toBeUndefined()
   })
 })
+
+describe('wrapped OpenCode run startup', () => {
+  it.each(['opencode', 'opencode2'] as const)(
+    'keeps %s run flags and positional task behind POSIX prefixes',
+    (agent) => {
+      for (const command of [
+        'CUSTOM_CONFIG=private opencode run --standalone',
+        'env CUSTOM_CONFIG=private opencode run --standalone',
+        'env -- CUSTOM_CONFIG=private opencode run --standalone',
+        'env -- CUSTOM_CONFIG=private opencode run --standalone --',
+        'env CUSTOM_CONFIG=private opencode run --title "--"'
+      ]) {
+        const plan = buildAgentStartupPlan({
+          agent,
+          prompt: '--literal task',
+          cmdOverrides: { [agent]: command },
+          platform: 'linux',
+          shell: 'posix',
+          isRemote: true,
+          agentEnv: { CUSTOM_CONFIG: 'kept' }
+        })
+        expect(plan?.launchCommand).toBe(
+          command.endsWith(' --') ? `${command} '--literal task'` : `${command} -- '--literal task'`
+        )
+        expect(plan?.env).toEqual({ CUSTOM_CONFIG: 'kept' })
+        expect(plan?.followupPrompt).toBeNull()
+      }
+    }
+  )
+
+  it.each(['opencode', 'opencode2'] as const)(
+    'preserves %s PowerShell call syntax and its run separator',
+    (agent) => {
+      for (const separator of ['', ' --']) {
+        const command =
+          '& "C:\\Program Files\\opencode\\opencode.exe" --log-level debug run --standalone' +
+          separator
+        const plan = buildAgentStartupPlan({
+          agent,
+          prompt: "--task's é",
+          cmdOverrides: { [agent]: command },
+          platform: 'win32',
+          shell: 'powershell',
+          agentEnv: { CUSTOM_CONFIG: 'kept' }
+        })
+        expect(plan?.launchCommand).toBe(command + (separator ? ' ' : ' -- ') + "'--task''s é'")
+        expect(plan?.env).toEqual({ CUSTOM_CONFIG: 'kept' })
+        expect(plan?.followupPrompt).toBeNull()
+      }
+    }
+  )
+})
diff --git a/src/shared/opencode-startup-prompt.ts b/src/shared/opencode-startup-prompt.ts
index 1dbe9c2719d..e3b1c462ffa 100644
--- a/src/shared/opencode-startup-prompt.ts
+++ b/src/shared/opencode-startup-prompt.ts
@@ -21,7 +21,7 @@ export function openCodeStartupPromptEnv(
   if (
     (agent !== 'opencode' && agent !== 'opencode2') ||
     !parsed.ok ||
-    isOpenCodeRunCommand(parsed.tokens)
+    isOpenCodeRunCommand(parsed.tokens, shell)
   ) {
     return env ? { env: { ...env } } : {}
   }