The agent runs inside the CALLER repo's checkout and opencode auto-discovers project-level config
from the working tree (opencode.json / .opencode/ for provider/model/permission/mcp/plugins, and
AGENTS.md/CLAUDE.md for instructions). opencode has no flag to disable that discovery, so any caller
repo could swap the model, unlock skills/permissions, register MCP servers or plugins (arbitrary
code execution on the runner, which holds ANTHROPIC_API_KEY/AGENT_TOKEN/TOKEN_*/SSH_PRIV_KEY), or
rewrite the rules the agent follows. The trigger gate only restricts who triggers, not what repo
content defines behavior.
- run-agent.sh: quarantine caller-controlled opencode.json/opencode.jsonc/.opencode/AGENTS.md/CLAUDE.md
for the duration of each run (moved aside, restored on EXIT via trap). Restore keeps the committed
tree/PR diff unchanged even when the agent commits mid-run.
- run-agent.sh: dev-agent golden rules now come from scripts/agent-rules.md (platform-authoritative),
injected into the prompt, instead of "read the caller's AGENTS.md and follow it exactly".
- scripts/agent-rules.md: new repo-agnostic authoritative rules.
- SECURITY.md: documents the isolation model and the requirement that callers pin agent.yml@main.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
