run: --command removed in v2 and slash commands are not expanded — no CLI path for headless command invocation

Description

OpenCode 2.0.8 removed --command from opencode run, and run does not expand slash commands in the message, so there is no CLI way to invoke a command headlessly.

--command was the supported headless path in v1 — see #7345, where the response was "use the --command mycmd ... we expect the flag". The migrate-v1 guide also says command definitions in .opencode/ "should continue to work without changes", and that supported behavior stopping in V2 is a compatibility bug.

This is a hard break for consumers, not an edge case. Spec Kit builds the invocation in its opencode integration (src/specify_cli/integrations/opencode/__init__.py): it synthesizes a /speckit.<name> prompt internally and then appends --command <name> to opencode run. The flag is not user-supplied, so affected users cannot work around it, and every Spec Kit workflow command step fails immediately on v2.

Observations from the same environment (2.0.8):

• GET /api/command returns data: [] even though the command above exists.
• POST /api/session/{sessionID}/command with {"name":"zzprobe","text":""} returns 204, so the server can execute the command — run just exposes no way to invoke it.

AI disclosure: this report was drafted with an AI assistant (OpenCode agent, model: DeepSeek V4.1 Flash) from commands and logs reproduced on the affected machine, and reviewed by the reporter before posting.

Plugins

None

OpenCode version

2.0.8

Steps to reproduce

1. Add a file-based command .opencode/commands/zzprobe.md:

   ---

   description: probe

   Reply with exactly the token PROBE_7391 and nothing else. Do not use any tools.

2. opencode run --command zzprobe "x"
   Actual: ERROR: Unrecognized flag: --command in command opencode run (exit 1)

3. opencode run "/zzprobe"
   Actual: the command is not expanded. The model receives the literal text /zzprobe and replies that it does not recognize the command.

4. opencode run --help
   Flags listed: --standalone --server --continue/-c --session/-s --fork --model/-m --agent --format --file/-f --title --thinking --auto (no --command)

Screenshot and/or share link

N/A (headless)

Operating System

Ubuntu 24.04.5 LTS (Linux 6.17.0-1032-oem, x86_64)

Terminal

Non-interactive / headless (spawned by a workflow runner, no TTY)

Start at the opencode run CLI entry point and inspect how its flags and message handling treat --command and /name inputs. The report also identifies src/specify_cli/integrations/opencode/__init__.py and the /api/command endpoints as compatibility references. Done means a file-based command can be invoked headlessly and the reproduction steps no longer fail.