Borrowing it
Nothing to install: this file belongs to Cyfrin/battlechain-lib. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Cyfrin/battlechain-lib/main/.agents/skills/battlechain/SKILL.mdgit clone --depth 1 https://github.com/Cyfrin/battlechain-libWrote 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/cyfrin/battlechain-lib/battlechain)<a href="https://agentmods.dev/skills/cyfrin/battlechain-lib/battlechain"><img src="https://agentmods.dev/badge/skills/cyfrin/battlechain-lib/battlechain/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/cyfrin/battlechain-lib/battlechain"><img src="https://agentmods.dev/badge/skills/cyfrin/battlechain-lib/battlechain.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 | $0.00069 | $0.02784 |
| Opus 5 | $0.00034 | $0.01392 |
| Sonnet 5 | $0.00014 | $0.00557 |
| Haiku 4.5 | $0.00007 | $0.00278 |
Grade A, and why
battlechain 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 217 lines — stays where its author put it; the contents beside it link to each section on GitHub.
BattleChain Development Standards
Instructions for working with BattleChain, from the Cyfrin security team.
What is BattleChain
BattleChain is a ZKSync-based L2 blockchain that inserts a battle-testing phase between testnet and mainnet: Dev -> Testnet -> BattleChain -> Mainnet. Protocols deploy audited contracts with real funds, whitehats legally attack them for bounties under Safe Harbor agreements, and surviving contracts promote to production.
Networks
| Network | Chain ID | RPC | Explorer | CAIP-2 | Status |
|---|---|---|---|---|---|
| BattleChain | 626 | https://mainnet.battlechain.com | https://explorer.mainnet.battlechain.com/ | eip155:626 |
Live — production network |
| BattleChain Testnet | 627 | https://testnet.battlechain.com | https://explorer.testnet.battlechain.com/ | eip155:627 |
Live — tooling default |
Both networks have a block explorer with an API and contract verification (mainnet API: https://block-explorer-api.mainnet.battlechain.com/api, testnet API: https://block-explorer-api.testnet.battlechain.com/api). The mock dependency contracts (tokens, Chainlink, Uniswap, etc.) are testnet-only. battlechain-lib tooling defaults to testnet; set NETWORK=mainnet to target mainnet.
Mainnet core contracts (chain 626)
| Contract | Address |
|---|---|
| Safe Harbor Registry (proxy) | 0xd229f4EE1bAE432010b72a9d1bD682570F4C6eBe |
| Registry Implementation | 0xBFF0ec94740c287932B50E64c2e8b380129B99a1 |
| Agreement Factory (proxy) | 0xCdB7F5C0F708baBaabE82afE1DbA8362023AcFdd |
| AgreementFactory Implementation | 0x8d4fEDF4462E3876Ae7C70CC0C5cebA482003Ad5 |
| Attack Registry (proxy) | 0x24876e481eC7198CAC95af739Df2a852CE65A415 |
| AttackRegistry Implementation | 0x03A3228A4ce38362289E715bbc26Cac8b98e421B |
| BattleChainDeployer | 0xD12765D21dDba418B8Fc0583c4716763e03Aa078 |
| Registry Moderator | 0x445d5685c4Ae71550Da0716b82B434AEA140E0c7 |
| CreateX | 0xa397f06F07251A3AEd53f6d3019A2a6cbd83E53e |
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.
- 8d ago First seen · 217 lines · 69 tokens per session scan A c32faa8c2507
battlechain is a skill published in the GitHub repository Cyfrin/battlechain-lib (5 stars, last pushed 8d ago), licensed Apache-2.0. It adds 69 tokens to every session and 2,784 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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