currency

A tool for getting daily fiat-currency exchange rates and converting amounts through the free Frankfurter API.

In plain words
What is it for?
Use it to convert money, look up supported currencies, or retrieve current, historical, and date-range exchange rates.
Why use it?
It avoids manually finding current or historical rates and provides a standard way to calculate conversions. It does not cover cryptocurrencies or precious metals.

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/atomicbot-ai/atomic-agent/currency
Any agent
npx skills add AtomicBot-ai/atomic-agent --skill currency
Clone the repo
git clone --depth 1 https://github.com/AtomicBot-ai/atomic-agent

Made for: Claude Code, Codex.

Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 851 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found 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 $0.00033 $0.00851
Opus 5 $0.00016 $0.00426
Sonnet 5 $0.00007 $0.00170
Haiku 4.5 $0.00003 $0.00085

Measured 2d ago against content hash c3e6228139ca, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

currency 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.

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.

[{ "tool": "os.shell.run", "args": { "cmd": "curl", "args": ["-fsS", "--max-time", "25", "https://api.frankfurter.dev/v1/latest?base=USD&symbols=EUR&amount=100"] } }]
starter-skills/currency/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

currency

Fetch exchange rates and convert money amounts through the free, key-less Frankfurter API (ECB-sourced fiat rates, updated daily ~16:00 CET). Prefer os.http.request GET; if the host allowlist is not null, it must include api.frankfurter.dev.

Fiat only — no crypto, no precious metals on v1. Rates refresh on business days, so weekend/holiday requests return the most recent business-day rate.

Endpoints (v1, stable)

Base URL: https://api.frankfurter.dev/v1

Goal URL
Latest, EUR base, all currencies /latest
Latest with base + targets /latest?base=USD&symbols=EUR,GBP
Convert an amount /latest?base=USD&symbols=EUR&amount=100
Historical (single day) /2024-01-15?base=USD&symbols=EUR
Time series (date range) /2024-01-01..2024-01-31?base=USD&symbols=EUR
Supported currencies /currencies

symbols is a comma-separated list of ISO 4217 codes. amount multiplies the returned rate, so amount=100&base=USD&symbols=EUR gives "100 USD in EUR".

Calling convention

Latest rate with os.http.request:

[{ "tool": "os.http.request", "args": { "method": "GET", "url": "https://api.frankfurter.dev/v1/latest?base=USD&symbols=EUR,GBP" } }]

Convert 250 USD to JPY:

[{ "tool": "os.http.request", "args": { "method": "GET", "url": "https://api.frankfurter.dev/v1/latest?base=USD&symbols=JPY&amount=250" } }]

Fallback if os.http.request is unavailable or the host is not allowlisted:

[{ "tool": "os.shell.run", "args": { "cmd": "curl", "args": ["-fsS", "--max-time", "25", "https://api.frankfurter.dev/v1/latest?base=USD&symbols=EUR&amount=100"] } }]

Response shape

{ "amount": 100.0, "base": "USD", "date": "2026-05-29", "rates": { "EUR": 92.13 } }

rates[<symbol>] already reflects amount. Always report the date so the user knows how fresh the quote is.

When to use

  • "What's the USD/EUR rate?", "convert 50 GBP to PLN", "rate of X in Y".
  • Historical FX on a given date, or a rate trend over a period.

Read the full file on GitHub · 85 lines

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 · 85 lines · 33 tokens per session scan A c3e6228139ca

Subscribe to this mod's changes

currency is a skill published in the GitHub repository AtomicBot-ai/atomic-agent (2,438 stars, last pushed today), licensed MIT. It adds 33 tokens to every session and 851 once invoked, about $0.0002 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.