opencode/.opencode/skills/opencode-dev/SKILL.md

name	description
opencode-dev	Use when interactively running, debugging, or verifying opencode's own CLI/TUI or server during development in this repo — starting the dev TUI, driving it with termctrl, hitting the server/API directly, reading log files, or attaching Bun's inspector.

Debugging opencode itself

Workflow for interactively exercising the CLI/TUI and server while developing in this repo. All commands below run from packages/cli unless noted otherwise.

Server/client model

opencode is a client/server system, not a single monolithic process:

• Server process runs the Effect HTTP API (packages/server) and owns all domain state: sessions, database, plugins, permissions, Location services. It's started by the serve command (packages/cli/src/commands/handlers/serve.ts).
• TUI process is a separate process that runs no application logic itself — it's an HTTP/SSE client of the server via @opencode/client (OpenCode.make).
• Discovery: CLI processes find the shared server through a JSON registration file at ~/.local/state/opencode/service.json (or service-local.json for the local/dev channel) containing {id, version, url, pid, password}; the password is used for HTTP Basic auth. Before reusing a registration, the client calls GET /api/info to confirm the server is alive, is the registered PID, and is version-compatible. opencode service status prints the registered URL.
• Sharing: because of this registration/health-check dance, many concurrent opencode/TUI invocations converge on one shared background daemon rather than each spawning their own. If no compatible healthy daemon is found, a new one is spawned detached (serve --service) and registers itself.
• bun dev service start|status|stop|restart manages this shared background daemon's lifecycle directly — useful when you need to force a fresh server, confirm one is running, or kill a stuck one.
• Standalone mode (--standalone) opts a single invocation out of the shared daemon: it spawns a private one-off serve --stdio --port 0 child tied to that invocation's lifetime, with its own random password. Use this to isolate a debugging session from your other running opencode sessions.
• Every log line is tagged role=server or role=cli and a per-process run=<id>, so you can distinguish server-side and client-side activity in one shared log file (see "Logs" below) even when both roles are interleaved from concurrent processes.

Starting the dev TUI

• packages/cli is the CLI and TUI entrypoint. bun dev from packages/cli and the repository-root bun dev both run packages/cli/src/index.ts.
• bun dev connects to the shared local-channel background service (service-local.json), starting it if needed. Every worktree on the machine shares that service. Add --standalone for a private server tied to this one process.
• Use bun run dev:live from the repository root to run this worktree's TUI against the installed opencode background server and your real sessions.

Interactive debugging with termctrl

• Use termctrl for interactive checks instead of starting the TUI as a blocking foreground process. It provides a real PTY, handles OpenTUI's host handshake, and can save reviewable screenshots.
• Use a dedicated session name and do not reuse or kill an unrelated session.

termctrl start opencode-dev --host opentui --cols 112 --rows 34 -- bun dev
termctrl wait opencode-dev "Ask anything" --timeout 20000
termctrl show opencode-dev

• Wait for visible text before interacting instead of relying on fixed sleeps. Use the text expected from the screen under test, such as Ask anything or Connect a provider.
• Drive the running TUI with termctrl send. Prefix typed input with text: and send control keys separately so the interaction matches real terminal input.

termctrl send opencode-dev 'text:example prompt' enter
termctrl send opencode-dev ctrl-c

• Use termctrl show after each meaningful interaction and inspect the full visible screen for rendering errors, stale state, error toasts, and unexpected exits.
• Save PNG evidence for every user-visible bug and fix. Do not save text captures; inspect the rendered PNG. Write temporary captures outside the repository unless the artifact is intended to be committed.

termctrl save opencode-dev --format png --out /tmp/opencode/tui.png

• For resize-sensitive changes, resize the viewport, wait for the expected content, and capture the screen again:

termctrl resize opencode-dev --cols 100 --rows 30
termctrl show opencode-dev

• Source changes may require restarting the process. Use termctrl restart opencode-dev rather than assuming the running TUI reloaded the change. Restarting the TUI does not restart the shared background service, so run bun dev service restart after server-side changes, or use --standalone.
• To exercise background-service behavior, use bun dev service start, bun dev service status, and bun dev service stop.
• Always clean up the Terminal Control session when the check is complete:

termctrl stop opencode-dev

Server/API debugging

• Use bun dev api --help from packages/cli to inspect the API debugging command. It sends one request to the server using the same daemon discovery/auth path as the CLI.
• Use bun dev api to introspect the server-side data backing the TUI. This is useful when debugging UI bugs: compare what the screen renders with the raw session, message, event, agent, or health data returned by the API to determine whether the bug is in the server state, the client data layer, or the TUI rendering.
• bun dev api accepts either an OpenAPI operation ID or a raw HTTP method plus path:

bun dev api get /api/info
bun dev api get /openapi.json
bun dev api <operationId> --param key=value

• Pass JSON request bodies with --data/-d; the command sets content-type: application/json automatically unless you provide a header. Add extra headers with --header/-H name:value.
• If no compatible background server is registered, bun dev api starts one through the daemon service. Use bun dev service status, bun dev service restart, and bun dev service stop when you need explicit lifecycle control.
• Prefer raw method/path calls for quick server debugging and operation IDs when exercising documented OpenAPI routes with path or query parameters.

Auditing installed opencode sessions

Installed (released) sessions use ~/.local/share/opencode/opencode.db and ~/.local/share/opencode/log/opencode.log. A local/dev checkout uses opencode-local.db and opencode-local.log instead, and OPENCODE_DB overrides the database. Run opencode service status before opencode api, because opencode api starts a server when none is healthy.

For a supplied ses_... ID, compare three sources:

• opencode api get /api/session/active and the Session/message endpoints for live server state.
• The database's ordered event rows for durable history.
• packages/tui/src/context/data.tsx and the relevant route for client projection and rendering.

Locate an uncertain database without modifying it:

SESSION=ses_...
for db in ~/.local/share/opencode/*.db; do
  sqlite3 "file:$db?mode=ro" "select 1 from session where id='$SESSION' limit 1" 2>/dev/null | grep -q 1 && printf '%s\n' "$db"
done

Logs

• Log files live under ~/.local/share/opencode/log/. In a local/dev checkout the active file is opencode-local.log; opencode.log is used for non-local (released) channel installs. Both are append-only, shared across every CLI and server process on the machine.
• Each line is structured key=value text: timestamp, level, run=<id> (per-process run ID), message, and a role=cli or role=server tag. Use run= to isolate one process's activity and role= to separate client-side from server-side log lines, since a shared daemon interleaves many processes' output in one file.
• Tail the live file while reproducing an issue instead of guessing from stale output:

tail -f ~/.local/share/opencode/log/opencode-local.log

• Filter to one run or role when the file is noisy:

grep 'run=8fc3b1d5' ~/.local/share/opencode/log/opencode-local.log
grep 'role=server' ~/.local/share/opencode/log/opencode-local.log

• OPENCODE_LOG_LEVEL controls verbosity (default INFO); set it before starting bun dev or serve to get DEBUG output for a specific repro.
• OPENCODE_PRINT_LOGS=1 additionally tees log output to stderr of the process that emitted it, which is useful when a process fails before you'd think to check the shared log file.
• termctrl logs <session> surfaces stdout/stderr for a Terminal Control session specifically (e.g. inspector output or startup failures before the TUI renderer starts) — use the log file above for anything emitted by a separate server/daemon process instead.

Heap snapshots

On every platform, including Windows, capture the running background server without restarting it or attaching an inspector:

opencode debug heap-dump

It discovers the already-running service (never starts or replaces one), calls POST /api/debug/heap-dump, waits until the file is complete, and prints its server-local path. Pass --server <url> (with OPENCODE_PASSWORD) for a server started with serve, and --directory <dir> to write somewhere other than the server's log directory (the server creates it; a server that predates the option ignores it and the CLI warns). A 404 means the running server predates the endpoint.

For desktop memory, run Capture heap snapshots from the desktop command palette (packages/gui-plugins/src/debug/main.ts). It writes ~/Downloads/opencode-heap-<time>/ with the desktop's own (local) server, which writes straight into the folder, every app window renderer, and the Electron main process. Heap snapshots only hold GC-managed objects, so it also records Chromium's memory-infra dump (memory-infra.json, open in Perfetto) and summarizes it per process and allocator in memory.json (MiB: malloc, partition_alloc, cc/tile_memory, gpu, v8, …), next to each window's DOM size and decoded images and the server's process.memoryUsage(). manifest.json (PIDs, app.getAppMetrics() before and after) is written last. Start with memory.json when a process is larger than its heap snapshot. In a dev desktop build you can drive it over CDP (OPENCODE_DESKTOP_REMOTE_DEBUGGING_PORT, default 9222): press Control+Shift+P, type heap snapshots, press Enter.

The Unix SIGUSR1 listener in packages/cli/src/heap.ts shares the same writer (packages/util/src/heap-snapshot.ts) and is still useful for a process that is not an HTTP server, such as a TUI client:

1. Find the processes and inspect their roles and memory:

pgrep -af opencode
ps -o pid,ppid,rss,vsz,lstart,etime,cmd -p <pid>,<pid>

2. Signal the process whose heap needs investigation. For shared-service memory, target the opencode serve --service process, not a TUI process:

kill -USR1 <server-pid>

3. Wait for heap snapshot written in the channel's log before opening the file. Snapshots are written to the same log directory as heap-<pid>-<timestamp>.heapsnapshot; writing a large heap can take several seconds and the file is incomplete until the completion message appears:

grep 'heap snapshot' ~/.local/share/opencode/log/opencode.log | tail
find ~/.local/share/opencode/log -maxdepth 1 -name 'heap-<server-pid>-*.heapsnapshot' -printf '%T@ %s %p\n' | sort -nr | head

Use opencode-local.log instead for a local/dev channel process. The log's path= field is authoritative.

4. Analyze the snapshot with Chrome DevTools, a V8 heap snapshot parser, or a temporary tool installed outside the repository. Start with the largest retained objects, dominators, object counts grouped by constructor/name, and retainer paths back to GC roots. Relate suspicious names and paths back to the source tree rather than treating large shallow allocations as leaks.

For command-line analysis, install tooling under /tmp/opencode, not in the repository. For example, MemLab can rank dominators and trace a reported heap object ID back to a GC root:

npm install --prefix /tmp/opencode/heap-analysis @memlab/cli
/tmp/opencode/heap-analysis/node_modules/.bin/memlab analyze object-size --snapshot <snapshot>
/tmp/opencode/heap-analysis/node_modules/.bin/memlab analyze shape --snapshot <snapshot>
/tmp/opencode/heap-analysis/node_modules/.bin/memlab trace --snapshot <snapshot> --node-id=<id>

A single snapshot explains what retains memory at one point in time, but does not by itself prove a leak. For leak confirmation, capture a baseline, perform a controlled repeated workload, allow idle cleanup/GC when possible, capture another snapshot, and compare growth and retainer paths. Also compare snapshot heap size with process RSS: a large difference can indicate native allocations, database mappings, allocator fragmentation, or other memory outside the JavaScript heap.

cat /proc/<pid>/smaps_rollup
pmap -x <pid> | sort -k3 -nr | head -25

Heap serialization itself can temporarily increase RSS and allocator high-water marks, so record ps/smaps_rollup both before and after capture. Large anonymous mappings with a comparatively small live heap require native-allocation or allocator investigation; they cannot be explained from JavaScript retainer paths alone.

CPU profiles

The CLI installs a SIGPROF listener on non-Windows processes in packages/cli/src/cpu-profile.ts. One signal starts a ten-second CPU profile and stops it automatically; additional signals are ignored while a profile is active. There is no CPU profile CLI flag or environment variable.

1. Get the PID from the info endpoint. For shared-service performance, target the server PID returned here rather than a TUI process:

opencode api get /api/info

Use bun dev api get /api/info instead when targeting the local/dev channel.

2. Start the capture:

kill -PROF <server-pid>

3. Wait for CPU profile written in the channel's log before opening the file. Profiles are written to the same log directory as cpu-<pid>-<timestamp>.cpuprofile; the log's path= field is authoritative:

grep 'CPU profile' ~/.local/share/opencode/log/opencode.log | tail
find ~/.local/share/opencode/log -maxdepth 1 -name 'cpu-<server-pid>-*.cpuprofile' -printf '%T@ %s %p\n' | sort -nr | head

Use opencode-local.log for a local/dev process. Load the completed .cpuprofile in Chrome DevTools or another V8 CPU profile viewer and inspect the hottest functions, call stacks, and self time during the controlled workload.

Debugger

• To debug the CLI or TUI with Bun's inspector, launch the CLI entrypoint through Terminal Control with an inspector URL, then attach a debugger to that URL:

termctrl start opencode-debug --host opentui --cols 112 --rows 34 -- \
  bun run --inspect=ws://localhost:6499/ src/index.ts

• Use --inspect-wait or --inspect-brk when execution must pause until a debugger attaches.
• Use termctrl logs opencode-debug for inspector output or startup failures emitted before the TUI renderer starts. Use termctrl show for the visible full-screen TUI.

Verification

• Run bun typecheck from packages/cli after CLI adapter changes.
• Run bun typecheck and bun test from packages/tui after shared TUI changes. Do not run tests from the repository root.
• Treat automated checks and Terminal Control smoke tests as complementary. For user-visible changes, verify initial render, the changed interaction, Ctrl-C exit behavior, and save a screenshot of the corrected state.