a2aproject/a2a-samples is a collection of code examples showing how AI agents communicate and delegate tasks through the Agent2Agent protocol, a shared way for agents built with different frameworks or languages to interoperate. Developers use it to learn and build multi-agent systems, with examples that include an agent server and a client host. The catalogue skill is one of the repository's agent-oriented additions.
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 a2aproject/a2a-samples --skill frankfurtergit clone --depth 1 https://github.com/a2aproject/a2a-samplesWrote 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/a2aproject/a2a-samples/frankfurter)<a href="https://agentmods.dev/skills/a2aproject/a2a-samples/frankfurter"><img src="https://agentmods.dev/badge/skills/a2aproject/a2a-samples/frankfurter/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/a2aproject/a2a-samples/frankfurter"><img src="https://agentmods.dev/badge/skills/a2aproject/a2a-samples/frankfurter.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Prompt Injection · line 12 Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
- high Prompt Injection · line 35 Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
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 | $0.00014 | $0.00418 |
| Opus 5.5 | $0.00006 | $0.00167 |
| Sonnet 5.5 | $0.00003 | $0.00084 |
| Haiku 4.5 | $0.00001 | $0.00042 |
Grade A, and why
frankfurter 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 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.
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.
What it actually says
frankfurter
Fetch currency exchange rates from the frankfurter.dev API.
get_latest_rates
Retrieve the latest exchange rates.
- Base URL: https://api.frankfurter.dev
- Method: GET
- Endpoint: /v1/latest
- Parameters:
- base (string): The base currency symbol (default: EUR).
- symbols (string): A comma-separated list of target currency symbols to filter.
get_historical_rates
Retrieve exchange rates for a specific past date.
- Base URL: https://api.frankfurter.dev
- Method: GET
- Endpoint: /v1/{date}
- Parameters:
- date (string, required): The date in YYYY-MM-DD format.
- base (string): The base currency symbol.
- symbols (string): A comma-separated list of target currency symbols.
get_time_series_rates
Retrieve exchange rates over a specific time period.
- Base URL: https://api.frankfurter.dev
- Method: GET
- Endpoint: /v1/{start_date}..{end_date}
- Parameters:
- start_date (string, required): Start date (YYYY-MM-DD).
- end_date (string): End date (YYYY-MM-DD). If omitted, defaults to the current date.
- base (string): The base currency symbol.
- symbols (string): A comma-separated list of target currency symbols.
get_available_currencies
Retrieve a list of all available currency symbols and their full names.
- Base URL: https://api.frankfurter.dev
- Method: GET
- Endpoint: /v1/currencies
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 · 52 lines · 14 tokens per session scan A d4880d024fec
frankfurter is a skill published in the GitHub repository a2aproject/a2a-samples (1,808 stars, last pushed 2d ago), licensed Apache-2.0. It adds 14 tokens to every session and 418 once invoked, about $0.0001 per session on Opus 5.5. 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.
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