Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/transilienceai/communitytools/blockchain-securitynpx skills add transilienceai/communitytools --skill blockchain-securitygit clone --depth 1 https://github.com/transilienceai/communitytoolsWrote 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/transilienceai/communitytools/blockchain-security)<a href="https://agentmods.dev/skills/transilienceai/communitytools/blockchain-security"><img src="https://agentmods.dev/badge/skills/transilienceai/communitytools/blockchain-security.svg" alt="Measured on agentmods" 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 | $0.00058 | $0.01154 |
| Opus 5 | $0.00029 | $0.00577 |
| Sonnet 5 | $0.00012 | $0.00231 |
| Haiku 4.5 | $0.00006 | $0.00115 |
Grade A, and why
blockchain-security scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl http://$HOST:$PORT/connection_info # -> PrivateKey, Address, TargetAddress, setupAddress Copies of this mod
1 near-identical copy found in the catalogue:
- blockchain-security — 88% identical, 8 lines differ
How it starts
The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Blockchain Security
Quick Start
- Download and decompile contracts (source or bytecode)
- Map storage layout and identify privileged operations
- Check for delegatecall, CREATE address prediction, reentrancy, access control
- Deploy exploit contracts via web3.py or cast/forge
- Verify win condition (isSolved/flag endpoint)
Blockchain CTF Challenge Pattern
# Get connection info
curl http://$HOST:$PORT/connection_info # -> PrivateKey, Address, TargetAddress, setupAddress
# RPC endpoint
RPC_URL="http://$HOST:$PORT/rpc"
# Win condition: Setup.isSolved() must return true
Key Attack Vectors
1. Delegatecall Storage Manipulation
When contract A does delegatecall to contract B, B's code runs with A's storage.
- Deploy exploit contract that mirrors A's storage layout
- Exploit contract writes to A's storage slots via delegatecall
- Critical: Storage layout must match exactly (same slot ordering)
- See reference/delegatecall-attacks.md
2. CREATE Address Prediction (Nonce Manipulation)
Contract addresses from CREATE are deterministic: keccak256(rlp([sender, nonce]))[12:]
- Brute-force nonce to find which nonce produces target address
- Send dummy transactions (self-transfers) to increment nonce
- Deploy exploit contract at the exact nonce that hits target address
- See reference/create-address-prediction.md
3. Storage Layout & Slot Computation
- Mappings:
keccak256(h(key) || uint256(slot_number))- Value types:
h(k) = abi.encode(k)(left-padded to 32 bytes) - String/bytes:
h(k) = keccak256(k)
- Value types:
- Read private variables via
eth_getStorageAt - See reference/storage-layout.md
4. Empty Array / Zero-Length Input Bypass
When a function loops over a user-supplied array to validate items (signatures, approvals, votes), passing an empty array skips the loop entirely. If there's no minimum-length check, validation is bypassed.
- Check:
for (uint i = 0; i < arr.length; i++)with norequire(arr.length >= N) - Exploit: Call the function with
[]to skip all validation
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 6d ago First seen · 101 lines · 58 tokens per session scan A 003c426b7908
blockchain-security is a skill published in the GitHub repository transilienceai/communitytools (509 stars, last pushed 1mo ago), licensed MIT. It adds 58 tokens to every session and 1,154 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
pentester-playwright
Phases 1b/3/4 authorized browser automation — SPA recon, multi-role auth, route/API catalog, PoC screenshots, Evidence landing (scoped proxy). Skill-gate read for web phases. Use when Phase 1b/3/4 web work, JS-rendered SPA, real browser needed, HAR/network capture, or Playwright PoC evidence.
osint-recon
Phase 1 conditional OSINT depth — four-dimension model (server→site→domain→people; people is conditional). Skill-gate companion to pentester-enum-services / pentester-recon. Use for passive OSINT depth, full recon dimensions, author tracking, not as Phase 0/Schema replacement.
pentester-exploit
Phase 4 exploitation — PoC construction, exploit-db/msf search, safe verification. Required Skill-gate read at Phase 4. Use when starting Phase 4, exploitation, exploit, PoC, exploit-db, msf, Metasploit, or payload delivery.
pentester-toolkit
Provision the pinned pentest toolset via DotSlash for the current scanenv (host-kali or kali-target-${ID}). Adapter, not a tool wrapper.
pentester-recon
Phase 1 intelligence recon methodology — passive+active recon, stack fingerprint, attack-surface map. Required Skill-gate read at Phase 1 (with pentester-enum-services). Use when starting Phase 1, intelligence gathering, recon, reconnaissance, OSINT prep, target profiling, or attack surface mapping.
pentester-waf-bypass
Phase 4 conditional — WAF/filter bypass for authorized CTF/range/pentest when payloads are blocked. Use at Phase 4 if blocked, or when user mentions WAF bypass, filter evasion, SQL/XSS/command-injection bypass, or security filter analysis.