Analyze. Act. Attest.
Close the loop on quality.
An LLM editing your code is a guess. act101 makes it a transform — your agent does the work, then act gate classifies the change, finds the tests that reach it, diffs the side-effects, and returns a deterministic MERGE / REVIEW / BLOCK verdict with a signed receipt and one-command rollback. 163 grammars, MCP and CLI, one native binary.
New here, and this already reads like gobbledegook? You don't have to understand any of it — your coding agent does.
Show me the plain version →Three stages. One provable change.
Analyze — 41 analyzers.
dead codecyclescouplinghotspotsseamsmap it before you touch it.
Act — 183 refactors.
renameextractinlinemovemodernizetransform it, cross-file, one invocation.
Attest — 6 verify ops + gate.
classifytests reachingside-effectsverdictreceipta deterministic verdict, not a rubber stamp.
$ act refactor extract-variable --file src/cart.ts --start-line 4 --start-column 14 --end-line 4 --end-column 35 lineTotal {"command":"refactor","operation":"extract_variable","applied":true,"changes_count":2,"files_affected":["src/cart.ts"],"impact_summary":"1 files, 2 locations, 0 references (checkpoint: ckpt-ee03fbe46f88-0000)","_meta":{"timing_ms":444,"output_tokens":52,"naive_tokens":40,"tokens_saved":0,"savings_pct":0.0,"operation_class":"write","deterministic_lines":0,"errors_prevented":0,"session":{"operations":1,"total_tokens_saved":0,"total_deterministic_lines":0,"total_errors_prevented":0,"agent_efficiency_ratio":0.0,"session_duration_ms":444}}} $ act gate act gate — working tree vs HEAD (1 changed function(s)) MERGE src/cart.ts::computeTotal — format (format-only) verdict: MERGE # extract-variable changed the text, not any modeled dimension → clears the gate $ act history undo ✓ Undid 1 operation(s); restored 1 file(s) on disk # now the agent makes a change that actually alters behavior… $ act gate act gate — working tree vs HEAD (1 changed function(s)) REVIEW src/cart.ts::computeTotal — behavior, 3 test(s) reach it (behavior change covered by 3 test(s)) verdict: REVIEW # behavior changed and tests cover it → routed to you, never auto-merged
Who's running the agent?
Verify every refactor your agent makes — before it merges.
For the individual engineer with an agent open.
→ Codebase owner / architectSee the structural drift. Prove the refactor. On every commit.
For the people who own the shape of the codebase.
→ Just here to buildI want my AI to code better — without getting into the technical details.
For everyone who lets the agent drive and just wants it to work better. Plain English, no jargon.
→An AI-Code Health Score for the repos your agent writes.
act101 online is the GitHub-native health scanner for AI-authored code: one grade, two halves — Security and Architecture. It runs in GitHub Actions and lands results where you already work — as a PR comment, a Check Run, and a SARIF upload that opens code-scanning alerts. Free for public repos.
- 18 query operations
- 5 codebase analyzers
- Rename + fix-auto
- 138 grammars
- Non-commercial projects
- Everything in Builder
- Extract, inline, wrap, introduce
- Generated constructors & accessors
- Refactor verification & receipts
- Commercial license
- Everything in Engineering
- Structural refactors & decomposition
- Code scaffolding tools
- Whole-codebase taint + git overlays
- Team licensing
- Everything in Architecture
- Legacy: COBOL, Fortran, Ada…
- Blockchain: Solidity, Vyper…
- GPU & shaders: CUDA, GLSL, HLSL, WGSL
All prices USD. 7-day free trial, all features.
And because act101 answers in one call instead of reading whole files, it runs ~85% leaner on tokens, too.
What each code intelligence and refactoring license unlocks
Code intelligence, semantic refactoring, architecture analysis, porting, and AI agent skills — broken out by tier so you can see exactly what Builder, Engineering, Architecture, and Elite include. Migration and porting are covered separately under Enterprise.
Install act. Give your AI agent real refactoring and porting tools.
One native Rust binary. No dependencies. No supply chain risk. No data exfiltration. One-command install for Claude Code, Cursor, Codex, Windsurf, Zed, and opencode.
$ curl -sSL https://raw.githubusercontent.com/act101-ai/act101/main/install.sh | sh
PS> irm https://raw.githubusercontent.com/act101-ai/act101/main/install.ps1 | iex
Install it straight from the marketplace, or set it up directly in your tool.
$ claude plugin marketplace add act101-ai/act101
$ claude plugin install act101@act101-marketplace
$ act install cursor
$ codex plugin marketplace add act101-ai/act101
# Then in any Codex session: /plugins → act101 → Install
$ act install windsurf
$ act install zed
$ act install opencode
Source, releases, and issue tracker on GitHub: github.com/act101-ai/act101 →
Built by an engineer who's spent a career on software that has to be correct
act101 was born out of decades of production experience across financial services, geospatial, automotive, medical devices, and biotech. It's the procedural verification layer built to make coding agents trustworthy: every edit an agent makes is classified, tested against the code that reaches it, and gated before it can merge. Read the story →
Your agent shouldn't ship code without proving it preserves behavior.
Install free.
Run agentic code transformation on your codebase.
Close the loop on quality.
Free forever for personal use · $29/mo commercial.
Works with every local agentic coding platform.