Agent skill

Simplify Codebase

by tt-a1i in tt-a1i/simplify-codebase

Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity.

MITAuto-check passedDevelopment

Install Simplify Codebase

skills CLI
$ npx skills add tt-a1i/simplify-codebase --skill simplify-codebase -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install tt-a1i/simplify-codebase simplify-codebase --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
simplify-codebase
GitHub stars
504
Token cost
~2.2k tokens
SKILL.md length
960 words
Files
54 (incl. references, assets)
Skills in repo
1
Repo updated
First seen
Licence
MIT

At a glance

Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity.

  • Works in 4 steps: Read the repository's instructions,… → Inspect version-control state and… → Trace the runtime path from entrypoints… → …
  • Evidence-backed deletion
  • SKILL.md covers Select mode and scope, Establish the contract, Cover the relevant surface and Build a proof record, plus 2 more sections
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Simplify Codebase is an agent skill from tt-a1i/simplify-codebase. Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity. Use for evidence-backed deletion or consolidation of dead code, duplicate state, redundant APIs or layers, ownerless abstractions, obsolete compatibility or design records, and over-engineering in any language; also use for 代码简化 or 熵回收. Do not use for general code review, onboarding, style-only refactoring, or performance tuning.

Its SKILL.md is about 2.2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 59 other files, including reference files and assets (for example `.github/workflows/cleanup-map.yml`, `.markdownlint.json` and `PRODUCT.md`).

It sits in Development, covering Refactoring and Code simplification. The repository describes itself as: Prove and remove accidental codebase complexity without breaking behavior. The licence is MIT.

When your agent uses it

  • Evidence-backed deletion
  • Consolidation of dead code
  • Duplicate state
  • Ownerless abstractions

Example prompts

  • “/simplify-codebase”

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

  1. Read the repository's instructions, architecture and decision records, manifests, test guidance, and generated-file conventions.
  2. Inspect version-control state and preserve unrelated work. Identify vendored, generated, migration, fixture, and public-package surfaces…
  3. Trace the runtime path from entrypoints through configuration, registration, dispatch, persistence, processes, and wire boundaries. Record…
  4. In Change mode, discover the repository's real verification commands and capture a proportional baseline when feasible. A failing baseline…

What it can do on your machine

Read from SKILL.md and the folder at commit 5da55ef. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Simplify Codebase loads about 2.2k tokens when it runs, and up to ~10k if it reads all its reference files. Until then it costs about 117 tokens; SKILL.md has 960 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~117
When it runs · the whole SKILL.md, loaded when a task matches
~2.2k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~10k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from tt-a1i/simplify-codebase at commit 5da55ef, republished under its MIT licence (© tt-a1i). 960 words, ~2,194 tokens.

Download SKILL.mdSave it as .claude/skills/simplify-codebase/SKILL.md (or your agent's skills folder). This skill also uses 53 other files; get the full folder from GitHub.
name
simplify-codebase
description
Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity. Use for evidence-backed deletion or consolidation of dead code, duplicate state, redundant APIs or layers, ownerless abstractions, obsolete compatibility or design records, and over-engineering in any language; also use for 代码简化 or 熵回收. Do not use for general code review, onboarding, style-only refactoring, or performance tuning.

Simplify Codebase

Reduce the number of concepts and obligations a codebase must keep coherent. Line-count reduction is supporting evidence, not the objective. A successful run may conclude that the inspected surface is already justified.

Select mode and scope

First choose the authority mode:

  • Survey for simplification audit, investigation, or candidate-finding requests. Remain read-only and return ranked evidence.
  • Change for explicit simplify, remove, consolidate, refactor, or repository-documentation edit requests. Prove each cut, implement it within the authorized scope, and validate the surviving contract.

Then choose the coverage scope:

  • Focused when the user names a subsystem, symbol, state machine, dependency, or suspected duplication. Cover that boundary thoroughly before expanding outward.
  • Broad when the request spans the repository or asks for multiple candidates. Partition the system and account for every in-scope domain.

Deleting a reachable capability, supported interface, stored representation, or compatibility path is a product decision. Describe the consequence and obtain direction unless the user has already chosen it.

Establish the contract

  1. Read the repository's instructions, architecture and decision records, manifests, test guidance, and generated-file conventions.
  2. Inspect version-control state and preserve unrelated work. Identify vendored, generated, migration, fixture, and public-package surfaces before classifying them.
  3. Trace the runtime path from entrypoints through configuration, registration, dispatch, persistence, processes, and wire boundaries. Record public, dynamic, persisted, generated, and compatibility-sensitive contracts.
  4. In Change mode, discover the repository's real verification commands and capture a proportional baseline when feasible. A failing baseline narrows what the final checks can prove.

Preserve authorization, trust-boundary validation, security isolation, accessibility essentials, data-loss prevention, stored-format compatibility, and cleanup that establishes quiescence. Treat changes to these protections as their own explicitly authorized objective, not an incidental simplification.

The contract map is complete when all in-scope entrypoints and authority boundaries are enumerated, each is traced far enough to name its owner and observable contract, and every uninspected or externally unknowable surface is recorded as a blind spot.

Cover the relevant surface

For every Broad engagement, and for Focused work involving dynamic architecture or dependency substitution, read investigation.md. Build a coverage map before ranking findings; the first plausible deletion must not end the survey.

For concurrency, cancellation, readiness, cleanup, defensive copies, validation, authorization, security isolation, accessibility, data-loss prevention, or cross-process data, also read boundaries-and-lifecycle.md.

Use repository-native search, compiler and linter output, dependency metadata, and history as discovery instruments. Treat their findings as leads until runtime consumers and contracts have been examined.

Build a proof record

For every in-scope lead that reaches consumer-map evidence or could retire a meaningful contract, record:

text
Finding ID: a stable report-local identifier such as S1 or S2
Candidate: the exact contract, representation, or layer to remove or merge
Locus: the ownership boundary, symbols, and exact paths or lines when verified
Topology: confirmed node and relationship IDs, primary locus, related nodes, route, and cut set when useful; otherwise not applicable
Burden: the concepts, synchronization, publication, or testing cost it creates
Reachability: production, non-production, dynamic, external, and persisted consumers
Rationale: why it exists and whether that reason remains current
Cut: declarations, implementations, branches, artifacts, docs, and dependencies affected
Consequence: observable capability or compatibility behavior surrendered
Confidence / risk: evidence strength, uncertainty, blast radius, and reversibility
Proof: the smallest check that would expose an incorrect cut
Net effect: maintenance concepts removed minus replacement or migration machinery added

Keep Finding IDs stable within the run so the summary, proof record, source links, and any visual companion refer to the same candidate. Do not invent a line number, owner, relationship, or route to fill the location fields. Mark unknown facts as unresolved.

Prove cut boundaries below file granularity when the candidate shares an artifact with surviving consumers. Account for candidate-exclusive selectors, members, fields, keys, registry entries, generated fragments, and fixtures without disturbing the surviving owners.

Keep or downgrade the candidate when a real consumer exists, dynamic reachability remains unresolved, a current decision still owns the design, the change merely relocates complexity, the result is outside scope or retires no meaningful obligation, or the available check cannot distinguish success from accidental breakage.

Rank confidence separately from benefit. A high-value guess does not outrank a smaller proved cut.

Candidate proof is complete when every qualifying lead is classified as ranked, rejected, or unresolved, and every unresolved lead names the fact required to decide it.

Show full SKILL.md (379 more words)Show less

Decide and act

In Survey mode, stop after reporting the ranked evidence. Include important rejected candidates when the rejection teaches something or identifies a concrete missing fact.

In Change mode, read execution-and-recovery.md and select the strongest authorized cut. One ownership boundary is the default batch size, not a run limit: for an explicitly requested set of cuts, finish and validate each boundary before starting the next.

If the user requests a simplification proposal, local cleanup annotation, or design-record consolidation, or if a selected change invalidates an ADR, RFC, design note, or architectural inventory, read decision-records.md. Do not turn an ordinary code audit into a repository-wide documentation purge.

If the user asks to combine findings from another branch, pull request, task, or agent run, read integrating-findings.md. Preserve evidence, not finding counts.

Generate a visual companion only when the user explicitly requests one or confirms an offer. If confirmed relationships would make a candidate clearer, explain what the map would clarify and ask before generating it. Without confirmation, complete the text report without a map; do not wait on visual delivery to finish the audit. For authorized visual delivery, read visual-reporting.md and use the bundled cleanup-map renderer. The map is an optional companion to the proof records, not evidence by itself. Do not write Survey artifacts into the target repository unless the user requested repository files.

Deliver the result

For a survey, report coverage, ranked proof records, rejected or unresolved high-value leads, and the next fact needed for each uncertainty. When a visual companion was requested or confirmed, report its status and cleanup-map Finding deep links separately.

Keep the handoff scan-friendly. Lead with the result, then include only the proof records, decision-relevant uncertainty, visual links, and validation that the user needs. Do not narrate the search process, repeat the same evidence under several labels, append generic advice, or keep empty sections. Concision does not remove required proof fields: write each field once, in the shortest form that preserves its subject, evidence strength, consequence, and boundary.

For a change, complete the validation and operation receipt defined in execution-and-recovery.md. A Before/Cut/After/Verify cleanup map may explain a structural change, but it never replaces the operation receipt. Report each validation layer separately; a narrow green check does not establish broader runtime, deployment, or user acceptance.

© tt-a1i, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 53 other files (references, assets) in the repository root of tt-a1i/simplify-codebase.

  • SKILL.md
  • .github/workflows/cleanup-map.yml
  • .markdownlint.json
  • LICENSE
  • PRODUCT.md
  • README.en.md
  • README.md
  • agents/openai.yaml
  • assets/hero.png
  • docs/validation.md
  • docs/visual-report-example.md
  • references/boundaries-and-lifecycle.md
  • references/decision-records.md
  • references/execution-and-recovery.md
  • references/integrating-findings.md
  • … and 39 more

Open the folder on GitHubat commit 5da55ef

Compare with similar skills

Simplify Codebase next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Simplify Codebase compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Simplify Codebase this skilltt-a1i/simplify-codebase504—~2.2kAutomated safety check: PassMIT
PonytailDavidObando/gsharp5648 repos~1.7kAutomated safety check: PassMIT
Code Simplification for ego-litecitrolabs/ego-lite17k—~1.2kAutomated safety check: PassMIT
Refactor Pass for Simplicitystar-history/star-history9.6k1 repos~168Automated safety check: PassMIT
RTK Rust Code Simplifierrtk-ai/rtk83k—~1.1kAutomated safety check: PassApache-2.0
Deslopmillionco/react-doctor15k—~1.2kAutomated safety check: PassCustom licence

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Categories

Questions about Simplify Codebase

What does Simplify Codebase do?

Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity. Simplify Codebase is an agent skill from tt-a1i/simplify-codebase. Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity.

When should I use Simplify Codebase?

Simplify Codebase fits situations like: evidence-backed deletion; consolidation of dead code; duplicate state; ownerless abstractions.

How do I install Simplify Codebase in Claude Code?

Run `npx skills add tt-a1i/simplify-codebase --skill simplify-codebase -a claude-code`. Or copy the skill folder (the tt-a1i/simplify-codebase repository) into .claude/skills/simplify-codebase in your project. Claude Code loads it when a task matches its description.

How do I install Simplify Codebase in Codex?

Run `npx skills add tt-a1i/simplify-codebase --skill simplify-codebase -a codex`. Or copy the skill folder (the tt-a1i/simplify-codebase repository) into .agents/skills/simplify-codebase in your project. Codex loads it when a task matches its description.

Can I use Simplify Codebase in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add tt-a1i/simplify-codebase --skill simplify-codebase -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/simplify-codebase, .gemini/skills/simplify-codebase, .github/skills/simplify-codebase and .opencode/skills/simplify-codebase in your project.

What does Simplify Codebase need to run?

SKILL.md names no scripts, command-line tools or credentials: Simplify Codebase is instructions for the agent only.

Does Simplify Codebase access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Simplify Codebase safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Simplify Codebase use?

Simplify Codebase is published under the MIT licence (from the LICENSE file in the skill folder). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Simplify Codebase use?

About 2.2k tokens (SKILL.md is roughly 8.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 8.2k tokens, read only when the agent opens those files.

What are the alternatives to Simplify Codebase?

Skills that share tags, products or a category with Simplify Codebase: Ponytail (DavidObando/gsharp, 564 stars), Code Simplification for ego-lite (citrolabs/ego-lite, 17k stars), Refactor Pass for Simplicity (star-history/star-history, 9.6k stars) and RTK Rust Code Simplifier (rtk-ai/rtk, 83k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Simplify Codebase?

tt-a1i (a GitHub user) maintains it in tt-a1i/simplify-codebase, which has 504 GitHub stars. The repository was last updated on September 4, 2026.

Source: tt-a1i/simplify-codebase on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.