base

A query tool for Base, a faster and cheaper Ethereum-compatible blockchain, with cryptocurrency prices added from CoinGecko.

In plain words
What is it for?
Use it to inspect wallets, tokens, transactions, gas costs, smart contracts, large transfers, network statistics, and prices on Base.
Why use it?
It gathers blockchain information without requiring an API key or extra Python packages.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/chemany/mente/base
Any agent
npx skills add chemany/Mente --skill base
Clone the repo
git clone --depth 1 https://github.com/chemany/Mente

Made for: Claude Code, Codex.

Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,025 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00051 $0.02025
Opus 5 $0.00026 $0.01012
Sonnet 5 $0.00010 $0.00405
Haiku 4.5 $0.00005 $0.00202

Measured 2d ago against content hash 76c43e8437ec, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

base 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 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/base_client.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

No API key needed. Uses only Python standard library (urllib, json, argparse).
Origin

This is a copy

100% identical to base — 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.

optional-skills/blockchain/base/SKILL.md · 232 lines

How it starts

The opening of the file, as written. The whole thing — 232 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Base Blockchain Skill

Query Base (Ethereum L2) on-chain data enriched with USD pricing via CoinGecko. 8 commands: wallet portfolio, token info, transactions, gas analysis, contract inspection, whale detection, network stats, and price lookup.

No API key needed. Uses only Python standard library (urllib, json, argparse).


When to Use

  • User asks for a Base wallet balance, token holdings, or portfolio value
  • User wants to inspect a specific transaction by hash
  • User wants ERC-20 token metadata, price, supply, or market cap
  • User wants to understand Base gas costs and L1 data fees
  • User wants to inspect a contract (ERC type detection, proxy resolution)
  • User wants to find large ETH transfers (whale detection)
  • User wants Base network health, gas price, or ETH price
  • User asks "what's the price of USDC/AERO/DEGEN/ETH?"

Prerequisites

The helper script uses only Python standard library (urllib, json, argparse). No external packages required.

Pricing data comes from CoinGecko's free API (no key needed, rate-limited to ~10-30 requests/minute). For faster lookups, use --no-prices flag.


Quick Reference

RPC endpoint (default): https://mainnet.base.org Override: export BASE_RPC_URL=https://your-private-rpc.com

Helper script path: ~/.hermes/skills/blockchain/base/scripts/base_client.py

python3 base_client.py wallet   <address> [--limit N] [--all] [--no-prices]
python3 base_client.py tx       <hash>
python3 base_client.py token    <contract_address>
python3 base_client.py gas
python3 base_client.py contract <address>
python3 base_client.py whales   [--min-eth N]
python3 base_client.py stats
python3 base_client.py price    <contract_address_or_symbol>

Procedure

0. Setup Check

python3 --version

# Optional: set a private RPC for better rate limits
export BASE_RPC_URL="https://mainnet.base.org"

# Confirm connectivity
python3 ~/.hermes/skills/blockchain/base/scripts/base_client.py stats

1. Wallet Portfolio

Read the full file on GitHub · 232 lines

Files

What ships with it

1 file 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.

Changes

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.

  1. 2d ago First seen · 232 lines · 51 tokens per session scan A 76c43e8437ec

Subscribe to this mod's changes

base is a skill published in the GitHub repository chemany/Mente (11 stars, last pushed 3mo ago), licensed MIT. It adds 51 tokens to every session and 2,025 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to base, differing in 0 lines, and is treated as a copy.

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