Display Name
Themis — AI-Native Unit Test Framework
Category
Agent Skills
Sub-Category
Slash-Commands: Code Analysis & Testing
Primary Link
https://github.com/vitron-ai/themis
Author Name
Vitron.AI
Author Link
https://github.com/vitronai
License
MIT
Other License
No response
Description
Unit test framework for Node.js/TypeScript with first-class Claude Code integration. npx themis init --claude-code
installs a skill, CLAUDE.md, four slash commands, and a PostToolUse hook that feeds structured failure clusters and repair
hints back into the conversation after edits. Drop-in Jest/Vitest alternative, 68% faster than Vitest. Tessl evals:
agents score 37% without the skill vs 97% with it.
Validate Claims
Install with npm install -D @vitronai/themis@latest, then run npx themis init --claude-code in any Node.js/TypeScript
project. This installs a CLAUDE.md, a skill at .claude/skills/themis/SKILL.md, and four slash commands under
.claude/commands/. Run npx themis test --reporter agent to see the structured JSON failure output with repair hints.
Tessl eval results are public at https://tessl.io/eval-runs/019d72a0-8211-74ea-84ef-a8e336ead3d2 (37% baseline → 97% with
skill, 10 scenarios). Performance benchmarks are reproduced by running npm run benchmark:showcase after cloning the
repo.
Specific Task(s)
Clone any Node.js/TypeScript project (e.g. https://github.com/sindresorhus/ky), install Themis with npm install -D @vitronai/themis@latest && npx themis init --claude-code, then ask Claude Code: "Generate and run unit tests for this
project using Themis." Claude will use the installed skill and slash commands to generate tests, run them with the agent
reporter, and fix any failures using the structured repair hints — without you copy-pasting docs or explaining the
framework.
Specific Prompt(s)
Run these commands first:
git clone https://github.com/sindresorhus/ky /tmp/ky-demo && cd /tmp/ky-demo
npm install
npm install -D @vitronai/themis@latest
npx themis init --claude-code
Then give Claude Code this prompt:
"Generate unit tests for the src/ directory using Themis, run them with /themis-test, and fix any failures using the
repair hints from the agent reporter output. Do not use Jest or Vitest."
Additional Comments
Themis is the first test framework that ships Claude Code-native integration (skill, slash commands, PostToolUse hook) as
a first-class feature rather than an afterthought. The key differentiator is the --reporter agent JSON output with
structured failure clusters and repairHints — Claude can act on parsed signals instead of re-reading stack traces, which
closes the edit-test-fix loop faster than any other test framework. Published on npm as @vitronai/themis and on the Tessl
registry as vitron-ai/themis.
Recommendation Checklist
Display Name
Themis — AI-Native Unit Test Framework
Category
Agent Skills
Sub-Category
Slash-Commands: Code Analysis & Testing
Primary Link
https://github.com/vitron-ai/themis
Author Name
Vitron.AI
Author Link
https://github.com/vitronai
License
MIT
Other License
No response
Description
Unit test framework for Node.js/TypeScript with first-class Claude Code integration.
npx themis init --claude-codeinstalls a skill, CLAUDE.md, four slash commands, and a PostToolUse hook that feeds structured failure clusters and repair
hints back into the conversation after edits. Drop-in Jest/Vitest alternative, 68% faster than Vitest. Tessl evals:
agents score 37% without the skill vs 97% with it.
Validate Claims
Install with
npm install -D @vitronai/themis@latest, then runnpx themis init --claude-codein any Node.js/TypeScriptproject. This installs a CLAUDE.md, a skill at .claude/skills/themis/SKILL.md, and four slash commands under
.claude/commands/. Run
npx themis test --reporter agentto see the structured JSON failure output with repair hints.Tessl eval results are public at https://tessl.io/eval-runs/019d72a0-8211-74ea-84ef-a8e336ead3d2 (37% baseline → 97% with
skill, 10 scenarios). Performance benchmarks are reproduced by running
npm run benchmark:showcaseafter cloning therepo.
Specific Task(s)
Clone any Node.js/TypeScript project (e.g. https://github.com/sindresorhus/ky), install Themis with
npm install -D @vitronai/themis@latest && npx themis init --claude-code, then ask Claude Code: "Generate and run unit tests for thisproject using Themis." Claude will use the installed skill and slash commands to generate tests, run them with the agent
reporter, and fix any failures using the structured repair hints — without you copy-pasting docs or explaining the
framework.
Specific Prompt(s)
Run these commands first:
Then give Claude Code this prompt:
"Generate unit tests for the src/ directory using Themis, run them with /themis-test, and fix any failures using the
repair hints from the agent reporter output. Do not use Jest or Vitest."
Additional Comments
Themis is the first test framework that ships Claude Code-native integration (skill, slash commands, PostToolUse hook) as
a first-class feature rather than an afterthought. The key differentiator is the --reporter agent JSON output with
structured failure clusters and repairHints — Claude can act on parsed signals instead of re-reading stack traces, which
closes the edit-test-fix loop faster than any other test framework. Published on npm as @vitronai/themis and on the Tessl
registry as vitron-ai/themis.
Recommendation Checklist