Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/JustineDevs/premortemnpx agentmods add skills/justinedevs/premortem/defi-attack-patternsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/justinedevs/premortem/defi-attack-patterns)<a href="https://agentmods.dev/skills/justinedevs/premortem/defi-attack-patterns"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/defi-attack-patterns/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/justinedevs/premortem/defi-attack-patterns"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/defi-attack-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00046 | $0.03343 |
| Opus 5.5 | $0.00018 | $0.01337 |
| Sonnet 5.5 | $0.00009 | $0.00669 |
| Haiku 4.5 | $0.00005 | $0.00334 |
Grade A, and why
defi-attack-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to defi-attack-patterns — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 356 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: DeFi Attack Patterns — Expert Attack Playbook
AI LOAD INSTRUCTION: Expert DeFi exploitation techniques. Covers flash loan mechanics, oracle manipulation (spot vs TWAP), MEV extraction (sandwich, JIT, liquidation), precision loss attacks, governance exploits, bridge vulnerabilities, and token standard pitfalls. Base models often miss the single-transaction atomicity constraint of flash loans and the distinction between spot price and TWAP manipulation.
0. RELATED ROUTING
- smart-contract-vulnerabilities for underlying Solidity vulnerability patterns (reentrancy, integer overflow, delegatecall)
- deserialization-insecure when targeting off-chain bridge relayer or indexer infrastructure
1. FLASH LOAN ATTACKS
1.1 Mechanism
Flash loans provide uncollateralized borrowing within a single transaction. The entire borrow → use → repay cycle must complete atomically; if repayment fails, the transaction reverts as if nothing happened.
| Provider | Max Amount | Fee |
|---|---|---|
| Aave V3 | Pool liquidity per asset | 0.05% (can be 0 for approved borrowers) |
| dYdX | Pool liquidity | 0 (uses internal balance manipulation) |
| Uniswap V3 | Pool liquidity per pair | 0.3% (swap fee tier) |
| Balancer | Pool liquidity | Protocol-configurable |
1.2 Price Oracle Manipulation
1. Flash borrow 100,000 WETH
2. Swap 100,000 WETH → TOKEN on AMM_A
→ TOKEN spot price on AMM_A skyrockets
3. On Lending_Protocol (reads AMM_A spot price as oracle):
→ Deposit small TOKEN collateral (valued at inflated price)
→ Borrow large amount of WETH against it
4. Swap TOKEN back → WETH on AMM_A (restore price)
5. Repay flash loan (100,000 WETH + fee)
6. Keep borrowed WETH from Lending_Protocol minus collateral cost
Key insight: protocols using AMM spot reserves (getReserves()) as price oracles are vulnerable. Must use TWAP or external oracle (Chainlink).
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 356 lines · 46 tokens per session scan A 8b80984dea98
defi-attack-patterns is a skill published in the GitHub repository JustineDevs/premortem (2 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 46 tokens to every session and 3,343 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to defi-attack-patterns, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
devloop
Goal-driven development loop — define objective, write rules with key-results, verify visually, sync to issue tracker.
skill0
Root index of x-cmd skill0 sub-skills. Defines the OKR-style agent workflow (goal → rule-verified results → execute), skill discovery, and agent tooling preferences. Style: principle-first, concise, delegate specifics to authoritative external sources.
vulnhunter-solana
Use when reviewing Solana program code for the account-model bug classes — unchecked account owner, absent signer, discriminator confusion, caller-controlled CPI seeds, PDA-derivation collision, SPL arithmetic overflow, close-and-reinitialize revival, and duplicate-account aliasing — the pattern census that stands in…
chain-construct-smart-contract
Use when you have a confirmed on-chain vulnerability hypothesis and must demonstrate it with a passing proof-of-concept — author an attacker contract or crafted instruction sequence for an EVM reentrancy, flash-loan, delegatecall-overwrite, or proxy-upgrade primitive (or a Solana CPI-privilege, account-substitution…
solana-audit-flow
Use when auditing an Anchor or bare-Rust Solana program end to end; because Solana ships no static analyzers, the coverage strategy is compiler-warning triage, manual source reading, LiteSVM and cargo tests, plus coverage-guided Trident and cargo-fuzz fuzzers before false-positive triage.
nodit-openapi-skill
Operate Nodit Web3 Data API reads through UXC with a curated OpenAPI schema, API-key auth, and overlap-aware guardrails.