Tallybuy for Hermes Agent

Compare delivered prices for products in Germany and Austria from inside Hermes Agent. The plugin connects Hermes to Tallybuy's public MCP server at https://tallybuy.com/mcp and adds one skill, tallybuy-shopping, that tells the agent how to use it.

No account, no key and no local code: the package is configuration only (plugin.json, mcp.json, skills/).

Install

hermes plugins install tallybuy        # from the Hermes plugin catalog, once listed
# or straight from this repository:
hermes plugins install https://github.com/tallybuy/hermes-plugin
hermes plugins enable tallybuy

Without the plugin, add the server by hand: copy config.yaml.example into ~/.hermes/config.yaml, then run /reload-mcp.

What it can do

Six read-only tools:

Tool	What it returns
list_markets	The markets Tallybuy covers (Germany, Austria) with their currency and language.
search_products	Products matching the words you give, in one market.
get_product	One product with its variants and content.
list_offers	Shop offers for one variant: price, delivery cost, delivered total, seller, time.
get_price_history	Past prices for one variant.
compare_items	A few variants side by side.

Example prompts:

• "Where is the Sony WH-1000XM5 cheapest in Germany, delivered?"
• "Compare these two monitors for delivery to Austria."
• "Is now a good time to buy this TV, going by its price history?"

How it answers

The skill sets the rules the agent follows:

• A price or delivery cost Tallybuy does not know is reported as unknown, never as zero.
• Every price comes with its shop and the time it was seen. Prices change.
• No basket totals across shops and no single "winner": the agent shows the offers and you choose.
• The agent sends you only to the offer's own link (purchase_url) and does not open it itself.

Disclosure

• Network calls. Every tool call is an HTTPS request to tallybuy.com. Nothing else is contacted, and nothing runs on your machine.
• What the server sees. Your IP address and the request, as for any web request. The address is used to limit requests per visitor; it is not linked to a person. Search words are used to answer and are not stored in a database. Details: privacy notice.
• Commission. Shop links are affiliate links. Tallybuy may earn a commission if you buy through one, at no extra cost to you. The skill tells the agent to say so.
• Limits. Requests are rate-limited per visitor. On 429 Too Many Requests the agent waits for Retry-After before trying again.
• No telemetry from the plugin. The tool set is served by tallybuy.com at runtime and is not fixed by this repository's commit.

Support

• Developer page: https://tallybuy.com/developers
• Issues: https://github.com/tallybuy/hermes-plugin/issues

License

MIT, see LICENSE.