constraint-handling-techniques

constraint-handling-techniques is a skill for Claude Code from hajibabaie/combinatorial-optimization-skills. It costs 121 tokens per session (11,578 once invoked), scanned A, original, MIT.

Techniques for keeping candidate solutions within the rules of a metaheuristic search. A metaheuristic is a general search method that tries many possible solutions rather than guaranteeing the best one directly.

In plain words
What is it for?
Use them to choose penalty functions, repair invalid candidates, preserve feasibility during search, decode candidates into valid solutions, apply stochastic ranking, or compare solutions with Deb’s feasibility rules.
Why use it?
They prevent the search from being dominated by invalid solutions and distinguish hard constraints from soft preferences. The choice can account for whether valid solutions are common or rare.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the combinatorial-optimization plugin — 76 skills shipped together

Good fit Use them to choose penalty functions, repair invalid candidates, preserve feasibility during search, decode candidates into valid solutions, apply stochastic ranking, or compare solutions with Deb’s feasibility rules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hajibabaie/combinatorial-optimization-skills/constraint-handling-techniques
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add hajibabaie/combinatorial-optimization-skills --skill constraint-handling-techniques
Clone the repo
git clone --depth 1 https://github.com/hajibabaie/combinatorial-optimization-skills

Made for: Claude Code.

Or install combinatorial-optimization, the plugin that ships this one along with the rest of its 76 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for constraint-handling-techniques

README.md
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Your own site
<a href="https://agentmods.dev/skills/hajibabaie/combinatorial-optimization-skills/constraint-handling-techniques"><img src="https://agentmods.dev/badge/skills/hajibabaie/combinatorial-optimization-skills/constraint-handling-techniques/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for constraint-handling-techniques

Your own site · 80×15
<a href="https://agentmods.dev/skills/hajibabaie/combinatorial-optimization-skills/constraint-handling-techniques"><img src="https://agentmods.dev/badge/skills/hajibabaie/combinatorial-optimization-skills/constraint-handling-techniques.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 121 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 11,578 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00121 $0.11578
Opus 5 $0.00060 $0.05789
Sonnet 5 $0.00024 $0.02316
Haiku 4.5 $0.00012 $0.01158

Measured 9d ago against content hash f3bc38957dce, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

constraint-handling-techniques scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/constraint-handling-techniques/SKILL.md · 768 lines

How it starts

The opening of the file, as written. The whole thing — 768 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Constraint-Handling Techniques

You are an expert in constraint handling for metaheuristics and evolutionary computation. This skill catalogs the six main technique families — penalty functions (static, dynamic, adaptive), repair operators, feasibility-preserving operators, decoder-based feasibility, stochastic ranking, and Deb's feasibility rules — with numpy implementations, complexity notes, and per-constraint-type selection guidance. Use the framework below to pick a technique per constraint, implement it correctly, and verify the choice empirically with a head-to-head experiment.

Initial Assessment

Establish these facts before recommending any technique:

  • Constraint inventory. List every constraint. For each: inequality or equality? Linear or black-box? How many?
  • Hard vs soft. Hard constraints define feasibility; soft constraints are preferences. Soft constraints belong in the objective (weighted or lexicographic), never in a feasibility mechanism. Confirm the user agrees on the split.
  • Feasible-region density. Sample random solutions: what fraction is feasible? Above ~10%, penalties and feasibility rules work out of the box. Below ~0.1%, you need repair, decoders, or feasibility-preserving operators — random search will never find the feasible region.
  • Constraint structure. Is feasibility cheap to check (O(n) capacity sums) or expensive (a simulation)? Cheap checks enable repair and move filtering; expensive checks favor penalties on cached violation values.
  • Representation already chosen? If the encoding is still open, the cheapest fix is to encode constraints away (permutation encoding for "visit each once", fixed-cardinality sets for "choose exactly k"). See solution-encodings before adding machinery here.
  • Algorithm family. Population methods (GA, DE, EDA) can rank by violation across a population; single-solution methods (SA, tabu, ILS) need per-move decisions — repair, move filtering, or a penalized delta.
  • Equality constraints present? Penalties handle equalities poorly (the feasible set has measure zero). Plan for reformulation, decoders, or projection-style repair.
  • Where does the optimum live? For most resource-constrained problems the optimum sits on the feasibility boundary (Michalewicz & Schoenauer 1996). Techniques that cannot search near or across the boundary lose quality.
  • Evaluation budget and time limit. Repair and decoding add per-individual cost; confirm the budget tolerates it.
  • Validation hook. Confirm an independent feasibility checker exists (separate from the fitness code) so the chosen technique can be audited — see solution-validation-testing.

Read the full file on GitHub · 768 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 768 lines · 121 tokens per session scan A f3bc38957dce

Subscribe to this mod's changes

constraint-handling-techniques is a skill published in the GitHub repository hajibabaie/combinatorial-optimization-skills (7 stars, last pushed 2mo ago), licensed MIT. It adds 121 tokens to every session and 11,578 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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