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 agiprolabs/claude-trading-skills --skill cost-basis-enginegit clone --depth 1 https://github.com/agiprolabs/claude-trading-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/agiprolabs/claude-trading-skills/cost-basis-engine)<a href="https://agentmods.dev/skills/agiprolabs/claude-trading-skills/cost-basis-engine"><img src="https://agentmods.dev/badge/skills/agiprolabs/claude-trading-skills/cost-basis-engine/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/agiprolabs/claude-trading-skills/cost-basis-engine"><img src="https://agentmods.dev/badge/skills/agiprolabs/claude-trading-skills/cost-basis-engine.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00030 | $0.03482 |
| Opus 5 | $0.00015 | $0.01741 |
| Sonnet 5 | $0.00006 | $0.00696 |
| Haiku 4.5 | $0.00003 | $0.00348 |
Grade A, and why
cost-basis-engine 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 12d 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 — 359 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cost Basis Engine
Compute cost basis for crypto trades using multiple accounting methods and compare the resulting tax liability across methods. This skill handles the full complexity of on-chain activity: partial sells, token migrations, airdrops, staking rewards, LP entry/exit, and multi-hop swaps.
Disclaimer: This skill provides computational tools for informational purposes only. It does not constitute tax, legal, or financial advice. Consult a qualified tax professional for your specific situation. Tax law varies by jurisdiction and changes frequently.
Prerequisites
- Python 3.10+
- No external dependencies required (standard library only)
- Trade history as a list of dicts or CSV with columns:
date,action,token,quantity,price_usd,fee_usd
Methods Overview
| Method | Logic | Best For |
|---|---|---|
| FIFO | First lots purchased are sold first | Simplicity, many jurisdictions' default |
| LIFO | Last lots purchased are sold first | Deferring gains when prices rise over time |
| HIFO | Highest-cost lots are sold first | Minimizing current tax liability |
| Specific ID | Trader selects which lots to sell | Maximum control, requires record-keeping |
| Average Cost | Weighted average of all held lots | Simplicity, required in some jurisdictions |
1. FIFO (First-In, First-Out)
Sell the oldest lots first. This is the default method in the US if no other method is elected.
def fifo_sell(lots: list[dict], sell_qty: float, sell_price: float) -> list[dict]:
"""Sell using FIFO. lots sorted oldest-first."""
remaining = sell_qty
realized = []
while remaining > 0 and lots:
lot = lots[0]
used = min(lot["qty"], remaining)
gain = (sell_price - lot["cost_per_unit"]) * used
realized.append({"qty": used, "basis": lot["cost_per_unit"], "gain": gain})
lot["qty"] -= used
remaining -= used
if lot["qty"] <= 0:
lots.pop(0)
return realized
What ships with it
2 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.
- 12d ago First seen · 359 lines · 30 tokens per session scan A c810d03e3b76
cost-basis-engine is a skill published in the GitHub repository agiprolabs/claude-trading-skills (354 stars, last pushed 8d ago), licensed MIT. It adds 30 tokens to every session and 3,482 once invoked, about $0.0002 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 2026-08-30.
Other skills, from other repositories
sector-rotation
An analysis framework for comparing industries in the Chinese A-share stock market, using business conditions, price momentum, valuation, and money flows. It produces rankings and higher- or lower-allocation suggestions.
strategy-pivot-designer
Detect backtest iteration stagnation and generate structurally different strategy pivot proposals when parameter tuning reaches a local optimum.
twitter-reader
Read Twitter/X for financial research using opencli (read-only). Use this skill whenever the user wants to read their Twitter feed, search for financial tweets, view bookmarks, look up user profiles, or gather market sentiment from Twitter/X. Triggers include: "check my feed", "search Twitter for", "show my…
chenhao-limit-up
A framework for judging Chinese A-share stocks that have reached the daily price-rise limit, using market mood, sector leadership, and trading momentum.
trading-risk-gate
Unified pre-trade safety gate: Ruin check (Law #1), ergodicity audit, and win-rate dominance validation. Absorbs: ergodicity-check, law-of-ruin, win-rate-dominance.
furusato
A Japanese hometown-tax donation manager for furusato nozei, a system where donations to municipalities can qualify for an income-tax or local-tax deduction. It reads donation receipts, stores donation records, and calculates deduction limits.