# opencode-acp-control

OpenCode ACP Skill Control OpenCode directly via the Agent Client Protocol (ACP). Metadata For ACP Protocol Docs (for Agents/LLMs): https://agentclientprotocol.com/llms.txt GitHub Repo: https://github.com/bjesuiter/opencode-acp-skill If you have issues with this skill, please open an issue ticket here: https://github.com/bjesuiter/opencode-acp-skill/issues Quick Reference ActionHowStart OpenCodebash(command: "opencode acp", background: true)Send messageprocess.write(sessionId, data: "\n")Read responseprocess.poll(sessionId) - repeat every 2 secondsStop OpenCodeprocess.kill(sessionId)List sessionsbash(command: "opencode session list", workdir: "...")Resume sessionList sessions → ask user → session/loadCheck versionbash(command: "opencode --version") Starting OpenCode bash(

command: "opencode acp",
background: true,
workdir: "/path/to/your/project"

) Save the returned sessionId - you'll need it for all subsequent commands. Protocol Basics All messages are JSON-RPC 2.0 format Messages are newline-delimited (end each with \n) Maintain a message ID counter starting at 0 Step-by-Step Workflow Step 1: Initialize Connection Send immediately after starting OpenCode: {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":1,"clientCapabilities":{"fs":{"readTextFile":true,"writeTextFile":true},"terminal":true},"clientInfo":{"name":"clawdbot","title":"Clawdbot","version":"1.0.0"}}} Poll for response. Expect result.protocolVersion: 1. Step 2: Create Session {"jsonrpc":"2.0","id":1,"method":"session/new","params":{"cwd":"/path/to/project","mcpServers":[]}} Poll for response. Save result.sessionId (e.g., "sess_abc123"). Step 3: Send Prompts {"jsonrpc":"2.0","id":2,"method":"session/prompt","params":{"sessionId":"sess_abc123","prompt":[{"type":"text","text":"Your question here"}]}} Poll every 2 seconds. You'll receive: session/update notifications (streaming content) Final response with result.stopReason Step 4: Read Responses Each poll may return multiple lines. Parse each line as JSON:

Notifications: method: "session/update" - collect these for the response
Response: Has id matching your request - stop polling when stopReason appears

Step 5: Cancel (if needed) {"jsonrpc":"2.0","method":"session/cancel","params":{"sessionId":"sess_abc123"}} No response expected - this is a notification. State to Track Per OpenCode instance, track: processSessionId - from bash tool (clawdbot's process ID) opencodeSessionId - from session/new response (OpenCode's session ID) messageId - increment for each request you send Polling Strategy Poll every 2 seconds Continue until you receive a response with stopReason Max wait: 5 minutes (150 polls) If no response, consider the operation timed out Common Stop Reasons stopReasonMeaningend_turnAgent finished respondingcancelledYou cancelled the promptmax_tokensToken limit reached Error Handling IssueSolutionEmpty poll responseKeep polling - agent is thinkingParse errorSkip malformed line, continueProcess exitedRestart OpenCodeNo response after 5minKill process, start fresh

Example: Complete Interaction

1. bash(command: "opencode acp", background: true, workdir: "/home/user/myproject") -> processSessionId: "bg_42"
2. process.write(sessionId: "bg_42", data: '{"jsonrpc":"2.0","id":0,"method":"initialize",...}\n') process.poll(sessionId: "bg_42") -> initialize response
3. process.write(sessionId: "bg_42", data: '{"jsonrpc":"2.0","id":1,"method":"session/new","params":{"cwd":"/home/user/myproject","mcpServers":[]}}\n') process.poll(sessionId: "bg_42") -> opencodeSessionId: "sess_xyz789"
4. process.write(sessionId: "bg_42", data: '{"jsonrpc":"2.0","id":2,"method":"session/prompt","params":{"sessionId":"sess_xyz789","prompt":[{"type":"text","text":"List all TypeScript files"}]}}\n')
5. process.poll(sessionId: "bg_42") every 2 sec until stopReason -> Collect all session/update content -> Final response: stopReason: "end_turn"
6. When done: process.kill(sessionId: "bg_42") Resume Session Resume a previous OpenCode session by letting the user choose from available sessions. Step 1: List Available Sessions bash(command: "opencode session list", workdir: "/path/to/project") Example output: ID Updated Messages

ses_451cd8ae0ffegNQsh59nuM3VVy 2026-01-11 15:30 12 ses_451a89e63ffea2TQIpnDGtJBkS 2026-01-10 09:15 5 ses_4518e90d0ffeJIpOFI3t3Jd23Q 2026-01-09 14:22 8 Step 2: Ask User to Choose Present the list to the user and ask which session to resume: "Which session would you like to resume?

1. ses_451cd8ae... (12 messages, updated 2026-01-11)
2. ses_451a89e6... (5 messages, updated 2026-01-10)
3. ses_4518e90d... (8 messages, updated 2026-01-09) Enter session number or ID:" Step 3: Load Selected Session Once user responds (e.g., "1", "the first one", or "ses_451cd8ae..."): Start OpenCode ACP: bash(command: "opencode acp", background: true, workdir: "/path/to/project")

Initialize:

{"jsonrpc":"2.0","id":0,"method":"initialize","params":{...}} Load the session: {"jsonrpc":"2.0","id":1,"method":"session/load","params":{"sessionId":"ses_451cd8ae0ffegNQsh59nuM3VVy","cwd":"/path/to/project","mcpServers":[]}}

Note: session/load requires cwd and mcpServers parameters.

On load, OpenCode streams the full conversation history back to you. Resume Workflow Summary function resumeSession(workdir):

# List available sessions

output = bash("opencode session list", workdir: workdir) sessions = parseSessionList(output) if sessions.empty: notify("No previous sessions found. Starting fresh.") return createNewSession(workdir)

# Ask user to choose

choice = askUser("Which session to resume?", sessions) selectedId = matchUserChoice(choice, sessions)

# Start OpenCode and load session

process = bash("opencode acp", background: true, workdir: workdir) initialize(process) session_load(process, selectedId, workdir, mcpServers: []) notify("Session resumed. Conversation history loaded.") return process Important Notes History replay: On load, all previous messages stream back Memory preserved: Agent remembers the full conversation Process independent: Sessions survive OpenCode restarts Updating OpenCode OpenCode auto-updates when restarted. Use this workflow to check and trigger updates. Step 1: Check Current Version bash(command: "opencode --version") Returns something like: opencode version 1.1.13 Extract the version number (e.g., 1.1.13). Step 2: Check Latest Version webfetch(url: "https://github.com/anomalyco/opencode/releases/latest", format: "text") The redirect URL contains the latest version tag: Redirects to: https://github.com/anomalyco/opencode/releases/tag/v1.2.0 Extract version from the URL path (e.g., 1.2.0) Step 3: Compare and Update If latest version > current version: Stop all running OpenCode processes: process.list() # Find all "opencode acp" processes process.kill(sessionId) # For each running instance Restart instances (OpenCode auto-downloads new binary on start): bash(command: "opencode acp", background: true, workdir: "/path/to/project") Re-initialize each instance (initialize + session/load for existing sessions) Step 4: Verify Update bash(command: "opencode --version") If version still doesn't match latest: Inform user: "OpenCode auto-update may have failed. Current: X.X.X, Latest: Y.Y.Y"

Suggest manual update: curl -fsSL https://opencode.dev/install | bash

Update Workflow Summary function updateOpenCode(): current = bash("opencode --version") # e.g., "1.1.13" latestPage = webfetch("https://github.com/anomalyco/opencode/releases/latest") latest = extractVersionFromRedirectUrl(latestPage) # e.g., "1.2.0" if semverCompare(latest, current) > 0:

# Stop all instances

for process in process.list(): if process.command.includes("opencode"): process.kill(process.sessionId)

# Wait briefly for processes to terminate

sleep(2 seconds)

# Restart triggers auto-update

bash("opencode acp", background: true)

# Verify

newVersion = bash("opencode --version") if newVersion != latest: notify("Auto-update may have failed. Manual update recommended.")

else:

notify("OpenCode is up to date: " + current) Important Notes Sessions persist: opencodeSessionId survives restarts — use session/load to recover

Auto-update: OpenCode downloads new binary automatically on restart

No data loss: Conversation history is preserved server-side