AI Systems Atlas

H-04Planner → Executor → Replanner

/harnesses/replanner

A plan is executed step by step, and rewritten whenever the environment disagrees with it.

Step-by-step walkthrough8 steps
  1. The planner drafts plan v1.
  2. Three steps, held as mutable state — not sacred text.
  3. Step 1 executes cleanly.
  4. Step 2 fails — the data has a format the plan never anticipated.
  5. The failure flows back to the planner as evidence.
  6. The plan mutates: step 2 is replaced in place.
  7. Execution resumes on the revised step…
  8. …and finishes. The original plan did not survive contact with reality.
Key insight

Treat the plan as mutable state, not scripture. The interesting engineering is in what evidence triggers a revision.

Failure mode

Thrash: a replanner that revises on every hiccup never finishes; one that revises too rarely is just Plan → Execute with extra cost.

Further reading
RelatedPlan → ExecuteRetry loop

Elsewhere in the atlas

Security →Evals →Context →Coding Agents →Tools →Ops →