0x-Shashi Audit Context Building Skill
Systematically build comprehensive understanding of a protocol before diving into code-level analysis. Rushing into code without context leads to missed vulnerabilities, wasted time, and incomplete coverage.
Why Context Building Matters
| Without Context | With Context |
|---|---|
| Miss cross-contract interactions | Map all trust boundaries before reading code |
| Spend time on low-risk functions | Prioritize functions handling value |
| Overlook admin-only backdoors | Know every privileged role and its power |
| Miss assumptions about external protocols | Document all external dependencies upfront |
| Can't identify broken invariants | Invariants identified before code review |
Time Allocation
For a typical DeFi protocol audit:
| Phase | Time % | Activity |
|---|---|---|
| Context building | 15-20% | Architecture mapping, docs review, invariants |
| Function-level analysis | 40-50% | Line-by-line code review with context |
| Cross-cutting concerns | 20-25% | Reentrancy, access control, value flows |
| Reporting | 10-15% | Writing findings, severity classification |
Capabilities
Architecture Mapping
- Contract inventory with purpose and SLOC
- Inheritance hierarchy (is-a relationships)
- Contract interaction graph (calls-to relationships)
- Proxy/upgrade pattern identification
- Library usage and dependency versions
Function-Level Analysis
- Access control classification (unrestricted / role-gated / owner-only)
- State change documentation (reads vs writes)
- External call mapping (call targets, data flow, return handling)
- CEI pattern compliance per function
- Edge case identification
Protocol Understanding
- Protocol invariant identification and documentation
- Trust boundary mapping (what trusts what)
- Token and value flow tracing
- Fee mechanism analysis
- Integration point documentation
Risk Surface Identification
- Centralization risk assessment (admin power)
- Oracle dependency risk
- External protocol dependency risk
- Upgrade mechanism risk
- Economic design risk areas
When to Use
| Trigger | Action |
|---|---|
| Starting a new audit | Full pre-audit context workflow |
| Reviewing unfamiliar protocol type | Architecture analysis first |
| Auditing upgradeable contracts | Storage layout + proxy analysis |
| Multi-contract system | Contract interaction mapping |
| Post-deployment review | Focus on live state + deployed config |
Workflows
- Pre-Audit Context — Complete before code review
- Architecture Analysis — Contract relationships and structure
- Deep Code Review — Function-by-function analysis
Resources
- Completeness Checklist — Ensure nothing is missed
- Function Analysis Example — Template with real example
- Output Template — Standardized context report format