OpenCode ACP Skill v2.0

Control OpenCode directly via the Agent Client Protocol (ACP) with automatic recovery and stuck detection.

🆕 What's New in v2.0

Quick Reference

🚀 Quick Start (Simple)

For most use cases, use this simple workflow:

1. exec(command: "opencode acp --cwd /path/to/project", background: true)
   -> sessionId: "bg_42"

2. process.write(sessionId: "bg_42", data: initialize_json + "\n")
   process.poll(sessionId: "bg_42", timeout: 10000)

3. process.write(sessionId: "bg_42", data: session_new_json + "\n")
   process.poll(sessionId: "bg_42", timeout: 10000)
   -> opencodeSessionId: "sess_xyz"

4. process.write(sessionId: "bg_42", data: prompt_json + "\n")
   adaptivePoll(sessionId: "bg_42", maxWaitMs: 120000)

5. When done: process.kill(sessionId: "bg_42")
   cleanupLocks()

📁 Skill Files

⚙️ Configuration

Option 1: Use defaults

All defaults are built-in. No config file needed.

Option 2: Customize

Copy config.default.json to config.json in the same folder and modify:

cp config.default.json config.json
# Edit config.json with your preferences

Config structure:

{
  "timeouts": { "initialize": 10000, "prompt": {...} },
  "retry": { "maxAttempts": 3, "initialDelay": 2000 },
  "polling": { "initial": 1000, "active": 2000 },
  "healthCheck": { "noOutputThreshold": 60000 },
  "recovery": { "autoRecover": true },
  "mcpServers": { "default": [], "supabase": ["supabase"] }
}

Timeouts (Configurable)

Retry Configuration

Adaptive Polling

🔄 Automatic Recovery

Stuck Detection

OpenCode is considered "stuck" when:

• No response after 2x expected timeout
• Health check fails 3 times in a row
• Process is still running but not responding to polls

Recovery Steps

When stuck is detected:

1. Cancel current operation: session/cancel
2. Wait 2 seconds
3. If still stuck: process.kill
4. Clean up locks
5. Restart OpenCode
6. Resume from last known session (if available)

Lock Cleanup

Lock files can become stale when OpenCode crashes. Always clean up:

# Before starting a new session
exec(command: "find ~/.openclaw/agents -name '*.lock' -mmin +30 -delete")

# After killing a stuck process
exec(command: "rm -f ~/.openclaw/agents/*/sessions/*.lock")

📋 Step-by-Step Workflow

Step 1: Pre-flight Check

Before starting, verify environment:

# Check OpenCode is installed
exec(command: "opencode --version")

# Clean stale locks (older than 30 minutes)
exec(command: "find ~/.openclaw/agents -name '*.lock' -mmin +30 -delete")

Step 2: Start OpenCode

exec(
  command: "opencode acp --cwd /path/to/project",
  background: true,
  workdir: "/path/to/project"
)
# Save sessionId for all subsequent operations

Step 3: Initialize (with retry)

// Send initialize
{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":1,"clientCapabilities":{"fs":{"readTextFile":true,"writeTextFile":true},"terminal":true},"clientInfo":{"name":"clawdbot","title":"Clawdbot","version":"2.0.0"}}}

Retry logic:

for attempt in 1..3:
    process.write(sessionId, initialize_json + "\n")
    response = process.poll(sessionId, timeout: 10000)
    
    if response contains protocolVersion:
        break  # Success
    
    if attempt < 3:
        sleep(2 * attempt)  # Backoff: 2s, 4s
    else:
        # Recovery mode
        process.kill(sessionId)
        cleanupLocks()
        restart from Step 2

Step 4: Create Session (with retry)

{"jsonrpc":"2.0","id":1,"method":"session/new","params":{"cwd":"/path/to/project","mcpServers":[]}}

Same retry logic as initialize.

Step 5: Send Prompts (with adaptive polling)

{"jsonrpc":"2.0","id":2,"method":"session/prompt","params":{"sessionId":"sess_xyz","prompt":[{"type":"text","text":"Your question here"}]}}

Adaptive polling:

elapsed = 0
interval = 1000  # Start at 1s
maxWait = 120000  # 2 minutes for complex tasks

while elapsed < maxWait:
    response = process.poll(sessionId, timeout: interval)
    
    if response contains stopReason:
        return response  # Done
    
    if response contains error:
        handle_error(response)
        break
    
    # Adaptive interval
    elapsed += interval
    if elapsed < 10000:
        interval = 1000      # First 10s: poll every 1s
    elif elapsed < 60000:
        interval = 2000      # 10-60s: poll every 2s
    elif elapsed < 120000:
        interval = 3000      # 60-120s: poll every 3s
    else:
        interval = 5000      # 120s+: poll every 5s

# Timeout reached - check if stuck
if is_stuck(sessionId):
    recover(sessionId)

Step 6: Health Check (Smart - No Token Waste)

⚠️ Don't poll constantly - wastes tokens!

Only do health checks when:

1. No output for >60s (possible stuck)
2. Approaching timeout (verify before declaring stuck)
3. Something looks wrong (partial errors, etc.)

DO NOT health check when:

• OpenCode is actively generating output
• <60s since last output

# Smart health check - only when needed
if time_since_last_output > 60000:  # 60s
    response = process.poll(sessionId, timeout: 5000)
    
    if response contains new data:
        last_output_time = now()
        continue  # Not stuck, just slow
    
    if response is "Process still running" with no data:
        # Still alive, just thinking - wait more
        continue
    
    if response is "No active session":
        # Process died - recover
        recover(sessionId)

Step 7: Cleanup

When done, always clean up:

process.kill(sessionId)
exec(command: "rm -f ~/.openclaw/agents/*/sessions/*.lock")

🛠️ Error Handling

Common Errors and Solutions

Recovery Function

function recover(sessionId, opencodeSessionId):
    # Step 1: Try to cancel gracefully
    process.write(sessionId, cancel_json + "\n")
    sleep(2000)
    
    # Step 2: Check if recovered
    response = process.poll(sessionId, timeout: 5000)
    if response is valid:
        return  # Recovered!
    
    # Step 3: Force kill
    process.kill(sessionId)
    
    # Step 4: Clean up
    exec("rm -f ~/.openclaw/agents/*/sessions/*.lock")
    
    # Step 5: Restart
    newSessionId = startOpenCode()
    initialize(newSessionId)
    
    # Step 6: Resume if we had a session
    if opencodeSessionId:
        session_load(newSessionId, opencodeSessionId)
    
    return newSessionId

🔌 Session Management

Multiple Sessions

OpenCode supports multiple concurrent sessions. Track them:

{
  "sessions": {
    "process_42": {
      "processSessionId": "bg_42",
      "opencodeSessionId": "sess_abc",
      "project": "/path/to/project1",
      "lastActivity": "2026-03-05T10:00:00Z",
      "status": "active"
    },
    "process_43": {
      "processSessionId": "bg_43",
      "opencodeSessionId": "sess_def",
      "project": "/path/to/project2",
      "lastActivity": "2026-03-05T09:30:00Z",
      "status": "idle"
    }
  }
}

Session Recovery

If OpenCode crashes mid-task:

1. Find the last opencodeSessionId
2. Start new OpenCode process
3. Initialize
4. session/load with the old sessionId
5. Continue from where it left off

📊 Monitoring

Health Metrics

Track these to detect problems early:

Logging

Log important events for debugging:

[2026-03-05 10:00:00] Started OpenCode, sessionId=bg_42
[2026-03-05 10:00:02] Initialized successfully
[2026-03-05 10:00:03] Created session sess_abc
[2026-03-05 10:00:05] Sent prompt: "Refactor auth module"
[2026-03-05 10:00:15] Received update (thinking)
[2026-03-05 10:00:45] Received update (tool use)
[2026-03-05 10:01:30] Completed, stopReason=end_turn

🎯 Best Practices

DO:

• ✅ Always clean up locks before starting
• ✅ Use adaptive polling (saves tokens)
• ✅ Implement retry logic (makes it robust)
• ✅ Track session state (enables recovery)
• ✅ Set appropriate timeouts per task type
• ✅ Kill and restart if stuck >2x timeout

DON'T:

• ❌ Poll every 2s for 5 minutes (wastes tokens)
• ❌ Health check every 30s when output is active (wastes tokens)
• ❌ Ignore stuck processes (blocks future work)
• ❌ Leave lock files after crashes
• ❌ Use same timeout for all operations
• ❌ Skip health checks when no output for >60s (misses stuck detection)

📝 Example: Robust Implementation

# State tracking
state = {
  processSessionId: null,
  opencodeSessionId: null,
  messageId: 0,
  retries: 0,
  lastActivity: null
}

# Start with cleanup
cleanupStaleLocks()

# Start OpenCode
state.processSessionId = exec("opencode acp --cwd /path", background: true)

# Initialize with retry
for attempt in 1..3:
  process.write(state.processSessionId, initialize())
  response = process.poll(state.processSessionId, timeout: 10000)
  
  if is_valid(response):
    break
  
  if attempt == 3:
    throw Error("Failed to initialize after 3 attempts")

# Create session with retry
for attempt in 1..3:
  process.write(state.processSessionId, session_new())
  response = process.poll(state.processSessionId, timeout: 10000)
  
  if is_valid(response):
    state.opencodeSessionId = response.result.sessionId
    break
  
  if attempt == 3:
    throw Error("Failed to create session after 3 attempts")

# Send prompt with adaptive polling
process.write(state.processSessionId, prompt(state.messageId, "Your task"))

elapsed = 0
interval = 1000
maxWait = 120000

while elapsed < maxWait:
  response = process.poll(state.processSessionId, timeout: interval)
  state.lastActivity = now()
  
  if contains_stop_reason(response):
    return parse_response(response)
  
  elapsed += interval
  interval = get_adaptive_interval(elapsed)
  
  # Smart health check - only if no output for >60s
  if elapsed > 60000 && no_recent_output:
    if is_stuck(state.processSessionId):
      state = recover(state)
      # Re-send prompt
      process.write(state.processSessionId, prompt(state.messageId, "Your task"))
      elapsed = 0

# Timeout
throw Error("Operation timed out after ${maxWait}ms")

🔧 Utility Functions

cleanupStaleLocks()

# Remove locks older than 30 minutes
find ~/.openclaw/agents -name '*.lock' -mmin +30 -delete

isStuck(sessionId)

# Check if process is alive but not responding
response = process.poll(sessionId, timeout: 5000)
return response == "Process still running" && no_data_for_60s

getAdaptiveInterval(elapsedMs)

if elapsedMs < 10000: return 1000
if elapsedMs < 60000: return 2000
if elapsedMs < 120000: return 3000
return 5000

📝 Prompt Templates

📝 Prompt Templates

See templates.md for pre-built prompts for common tasks:

Usage:

1. Read templates.md
2. Find appropriate template
3. Replace placeholders with your specifics
4. Send as prompt

📊 Metrics & Monitoring

Track these for health monitoring:

Logging format:

[2026-03-05 10:00:00] INFO: Started OpenCode, sessionId=bg_42
[2026-03-05 10:00:02] INFO: Initialized successfully
[2026-03-05 10:00:03] INFO: Created session sess_abc
[2026-03-05 10:00:05] INFO: Sent prompt (refactor)
[2026-03-05 10:00:15] DEBUG: Received update (thinking)
[2026-03-05 10:00:45] DEBUG: Received update (tool use)
[2026-03-05 10:01:30] INFO: Completed, stopReason=end_turn
[2026-03-05 10:01:31] INFO: Metrics: duration=91s, polls=15, retries=0

Log levels:

• ERROR - Failures, exceptions, stuck detected
• WARN - Retries, slow responses, near-timeout
• INFO - Start, complete, cleanup
• DEBUG - Detailed output, updates received

📦 Skill Files

opencode-acp-control-3/
├── SKILL.md              # This file
├── opencode-session.sh   # Helper script (executable)
├── config.default.json   # Default configuration
├── templates.md          # Prompt templates
├── _meta.json            # Skill metadata
└── .clawhub/             # ClawHub metadata

🚀 Helper Script (Recommended)

Use opencode-session.sh for automatic workflow:

# Simple usage
~/.openclaw/workspace/skills/opencode-acp-control-3/opencode-session.sh \
  --project /path/to/project \
  --prompt "Add error handling to the API"

# With template
opencode-session.sh \
  --project ~/myapp \
  --template "Add API endpoint" \
  --prompt "POST /api/users with validation"

# Complex task
opencode-session.sh \
  --project ~/myapp \
  --timeout complex \
  --mcp '["supabase"]' \
  --prompt "Create migration for users table"

Script options:

What the script provides:

The script outputs a complete workflow with:

• ✅ Pre-flight cleanup
• ✅ Exact JSON-RPC messages to send
• ✅ Retry logic hints
• ✅ Adaptive polling intervals
• ✅ Health check thresholds
• ✅ Cleanup commands

CYPHER should:

1. Execute the script with options
2. Parse the output
3. Execute the steps in order
4. Log metrics at the end

Version 2.2.0 - Released 2026-03-05 Changes: Added opencode-session.sh helper script