Pinky and the Brain: my agent/subagent duo

Know Your Tools, Productivity, AI 2 Minutes

OpenCode‘s agents configuration and Beads. A match made in heaven.

My flow until now

Working on a task starts with the Plan agent. I provide an initial prompt of what I want to achieve and the agent responds with a plan. If the plan needs adjustments I ask the agent to update it. When I’m satisfied with the final outcome I move to the execution of the plan. This will happen in one of two ways:

  1. If the context window is still small I simply change agents1 (move to Build) and ask it to proceed with the execution.
  2. If the context window is already big I ask the agent to save the plan in a markdown file, start a new session and ask the Build agent to read the file and execute the plan.

This flow works but there are a few drawbacks that bother me:

  • There is no human in the loop. I end up reviewing all changes at the end of the execution.
  • Even if I start a new session, depending on the size of the plan, the context window might get big causing the agent to misbehave. Especially in changes that must be repeated.
  • I usually use Opus for planning and Haiku for execution. There are times though that I forget to make the change ending up using Opus for everything. Opus is good but is also expensive!
  • You can’t easily pause the flow and continue from where you stopped.

My new flow

My new flow is based on one agent, one subagent and a database. In particular:

  1. Like before I start with an agent that will help me build a detailed plan that consists from a number of tasks.
  2. When I’m happy with the plan I ask the agent to use Beads and save each task under an epic.
  3. Then I ask the agent to start the execution loop.

Execution loop

  1. The agent uses Beads to figure out which task must be executed. It changes its status to in_progress and asks the subagent to execute it.
  2. The subagent reads the task, makes the necessary changes and informs the agent that it finished.
  3. The agent asks me to review the changes and approve them or not.
  4. If I approve the changes, the agent commits them, close the task and move to the next one.
  5. If I request changes, the agent asks the subagent to make them. At this point we move to step 2 again. We remain at this inner loop until I give my approval.

Pinky and the Brain2

If you didn’t make the connection yet, Brain is the name I gave to the agent (type primary) and Pinky is the subagent.

I did not created them on my own. I asked OpenCode to help me by describing the flow I wanted. OpenCode read its own docs, asked me a couple of clarifying questions and came up with these:
Brain: https://gist.github.com/le0nidas/aae1c9f1b35110a00b7157b6c2437444
Pinky: https://gist.github.com/le0nidas/b8a3a89131a639e39e42f7aaf794cf33

Benefits

  • I am finally in the loop. I review fewer changes at a time and sooner!
  • Using subagents for each task keeps both the agent’s and the subagent’s context window smaller and cleaner ending up in fewer, to none, misbehaviors.
  • Brain is tied with Opus and Pinky with Haiku. No need to remember to change anything!
  • The best of all, with Beads I can pause and resume whenever I want. The agent knows where to start from!

PS: if you are part of team and don’t want to pollute the codebase with various configurations, you can (a) init beads in stealth mode and (b) exclude .opencode folder from git

  1. according to the docs, all primary agents share the main conversation hence share the same context window ↩︎
  2. https://www.imdb.com/title/tt0112123/ ↩︎
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