pddl-solver

name	pddl-solver
description	Use this skill when the user wants to SOLVE a PDDL planning instance — given a domain.pddl and problem.pddl, produce a valid plan. Triggers: "solve this PDDL problem", "find a plan for", "generate a plan", domain.pddl + problem.pddl together, "what plan achieves this goal", plan validation, plan repair, "check if this plan is valid", "fix this invalid plan".

PDDL Solver Skill

Read the domain and problem files and produce a valid plan.

Generate a Plan

Read the domain and problem files. Produce a plan — one (action-name arg1 arg2) per line — that achieves the goal from the initial state.

Validate

Write the plan to a file, then run:

uv run python scripts/validate_plan.py domain.pddl problem.pddl plan.txt

The validator outputs:

• VALID: Plan achieves goal in N steps — done
• INVALID at step K: (action args) followed by the unmet precondition and current state
• INVALID: Goal not achieved. Missing atoms: [...]

Repair if Invalid

If the validator reports an error, fix the issue and re-validate. Repeat up to 3 attempts. If the plan still fails after 3 attempts, report the failure honestly and suggest an external planner (pyperplan, Fast Downward).

Output

Present the validated plan as a plain list of actions:

(action1 arg1 arg2)
(action2 arg1 arg3)

References

• PDDL syntax: references/pddl_syntax.md
• Failure modes and repairs: references/debugging_guide.md
• Worked example: assets/few_shot_examples/blocksworld_solved.txt