You can get a lot done with agentic programming without going "all in" on a gastown-like system, but I think there is a minimum viable setup:
1. an adversarial agent harness that uses one agent to create a plan and implement it, and another to review the plan and code-review each step.
2. an agentic validation suite -- a more flexible take on e2e testing.
3. some custom skills that explain how to use both of those flows.
With this in place you can formulate ideas in a chat session, produce planning artifacts, then use the adversarial system to implement the plans and the validation layer to get everything working e2e for human review.
There are a lot of tools you can use for these things but I chose to just build the tooling in the repo as I go.
Claude already creates multiple agents for some projects just to keep context windows smaller. I don't think it'll be long before they offer a testing agent along with their planning agent.
I prefer having codex author plans and implement, and claude play reviwer. I do swap them from time to time and i have a lot of respect for claude 4.6 and 4.7 but for my domain I think codex does a better job with the authoring.
You're definitely burning more tokens with the back/forth and multi-step approach but assuming you swap who does the authoring from time to time you can definitely get the max out of each plan. Review doesn't use as many tokens.
1. an adversarial agent harness that uses one agent to create a plan and implement it, and another to review the plan and code-review each step.
2. an agentic validation suite -- a more flexible take on e2e testing.
3. some custom skills that explain how to use both of those flows.
With this in place you can formulate ideas in a chat session, produce planning artifacts, then use the adversarial system to implement the plans and the validation layer to get everything working e2e for human review.
There are a lot of tools you can use for these things but I chose to just build the tooling in the repo as I go.