behavior-contract
SkillDev toolsLets your agent turn bug preconditions and postconditions into testable behavior contracts.
Available today. Use it from your connected AI after setup.
No other account needed.
Connect ahel once, and every AI you use reads what you have installed.
Then ask your AI: use the behavior-contract skill
About this capability
Bug condition/postcondition formalization as testable Behavior Contracts. Defines invariants that must be preserved across fixes.
What this skill tells your AI
The instructions your AI receives, as published by a5c-ai/babysitter in library/methodologies/pilot-shell/skills/behavior-contract/SKILL.md and read by ahel’s review.
- "Positive amounts still process correctly"
- "Negative amounts still throw
InvalidAmountError" - "Receipt format remains unchanged for all amount types"
Contract Document Template
# Behavior Contract: [Bug Title]
## Bug Condition
[Precise description of triggering conditions]
## Postcondition
[Expected correct behavior after fix]
## Invariants
- [ ] Invariant 1: [existing behavior to preserve]
- [ ] Invariant 2: [existing behavior to preserve]
## Testable Assertions
1. `expect(processPayment(0)).toEqual({ amount: 0, status: 'completed' })`
2. `expect(processPayment(100)).toEqual({ amount: 100, status: 'completed' })`
3. `expect(() => processPayment(-1)).toThrow(InvalidAmountError)`
Usage in Bugfix Workflow
- Bug analysis identifies root cause at file:line
- This skill formalizes the contract from the analysis
- tdd-enforcer writes failing test from Bug Condition
- tdd-enforcer writes preservation tests from Invariants
- Minimal fix applied, contract audited
Signals
- GitHub stars
- 2k
- Forks
- 106
- Last commit
- Sep 2026
Advanced
- Catalog kind
- skill
- Gateway key
behavior-contract- Source
- github.com/a5c-ai/babysitter