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 skills add blockscout/agent-skills --skill web3-devgit clone --depth 1 https://github.com/blockscout/agent-skillsWrote 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/blockscout/agent-skills/web3-dev)<a href="https://agentmods.dev/skills/blockscout/agent-skills/web3-dev"><img src="https://agentmods.dev/badge/skills/blockscout/agent-skills/web3-dev/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/blockscout/agent-skills/web3-dev"><img src="https://agentmods.dev/badge/skills/blockscout/agent-skills/web3-dev.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 | $0.00212 | $0.07142 |
| Opus 5.5 | $0.00085 | $0.02857 |
| Sonnet 5.5 | $0.00042 | $0.01428 |
| Haiku 4.5 | $0.00021 | $0.00714 |
Grade A, and why
web3-dev 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 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl --request GET \ How it starts
The opening of the file, as written. The whole thing — 350 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Web3 Dev — Blockscout PRO API
This skill teaches the agent how to build software (apps, scripts, CLIs, bots, mobile/desktop clients) that reads blockchain data through the Blockscout PRO API — a single HTTP API covering 100+ EVM chains (94+ L2s and scaling projects). One API key works on every supported chain; switch chains by changing the chain_id path parameter on the call.
The PRO API returns explorer-enriched data: indexed, decoded, and structured — token metadata, proxy implementations, internal transactions, contract context, and so on. Use it for dApps and wallets, AI agents and bots, analytics platforms, and operational tooling.
For data the explorer has not pre-indexed — most importantly live or historical contract state at a specific block (e.g. balanceOf(addr) against a token contract at block N, totalSupply() at a past block, any view-function call, contract storage reads) — the PRO API also exposes eth_call through its JSON-RPC gateway. See Reading contract state. The same Bearer-token auth covers both surfaces; you do not need a separate RPC endpoint for historical contract reads.
The bundled files in references/ are the single source of truth for which endpoints exist and how to call them:
| File | Purpose |
|---|---|
references/pro-api-index.md |
One-line summary of every endpoint, grouped by OpenAPI tag. Always start here. |
references/pro-api.json |
Full OpenAPI v3 specification (~24,000 lines). Do not read whole — query it with oastools. |
Do not classify endpoints into your own "families" or steer the user toward a subset. Every endpoint listed in the index is callable, and every endpoint uses the same authentication scheme described below.
API key — mandatory pre-flight
A PRO API key is required for every PRO API call. Run the following pre-flight before issuing the first request in a session.
Pre-flight check (in this order)
What ships with it
4 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.
- 1mo ago First seen · 350 lines · 212 tokens per session scan A c3b62963091b
web3-dev is a skill published in the GitHub repository blockscout/agent-skills (46 stars, last pushed 4mo ago), licensed MIT. It adds 212 tokens to every session and 7,142 once invoked, about $0.0008 per session on Opus 5.5. 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.
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