BestPrice MCP
by TheBestCo
README.md
# BestPrice MCP
[](https://github.com/TheBestCo/bestprice-mcp/actions/workflows/test.yml)
[](https://glama.ai/mcp/servers/TheBestCo/bestprice-mcp)
[](LICENSE)
The official [Model Context Protocol](https://modelcontextprotocol.io/) server for
[BestPrice.gr](https://www.bestprice.gr/), Greece's price-comparison service. It gives AI
assistants read-only access to shopping decisions, live product search, offer comparison,
and price history. No account or API key is needed.
## Start shopping
- [Open BestPrice in ChatGPT](https://chatgpt.com/plugins/plugin_asdk_app_6a8d8ed6e2bc8191b3caaf7214f3c981) and add the published plugin.
- [Connect BestPrice to Claude](https://claude.ai/customize/connectors?modal=add-custom-connector&connectorName=BestPrice&connectorUrl=https%3A%2F%2Fmcp.bestprice.gr%2Fmcp) using the prefilled connector form.
- See the [shopping guide](https://www.bestprice.gr/en/mcp) for examples and other assistants.
For developer integrations, the public endpoint is:
```text
https://mcp.bestprice.gr/mcp
```
- Transport: Streamable HTTP over HTTPS; anonymous shopping, optional OAuth for Events
- Official Registry ID: `gr.bestprice/mcp`
- Server version: `1.8.4`
- Public guide: <https://www.bestprice.gr/mcp>
- Support: <https://www.bestprice.gr/contact>
This repository holds everything that lives outside the hosted service: the install
manifests for each AI client, a local stdio bridge for hosts that cannot speak HTTP, and
the browser-native WebMCP layer. The server itself is not in this repository.
The [current release matrix](submission/current-release-matrix.md) records the
live gateway, UI, OAuth/Events, plugin review and separate ACP qualification.
## Tools
| Tool | What it does | Key arguments |
| --- | --- | --- |
| `get_shopping_decision` | Runs the BestPrice Shopping Brain: an evidence-backed recommendation, need-based comparison, or read-only basket plan with reasons, tradeoffs, and unknowns. | `message` (the need in Greek or English, including any budget), optional `postal_code` (required for a completed basket plan), optional `evidence_detail` (`summary`, the default: only the evidence the answer cites; `full`: every claim and source) |
| `search_products` | Finds canonical products in the catalog. Returns product IDs and the catalog minimum price before shipping. | `query` (2–200 characters: a name, model, category, or a bare GTIN/EAN barcode), optional `price_min`, `price_max`, `required_features`, `sort` (`relevance`, `price_asc`, `price_desc`), `limit` (1–8) |
| `compare_offers` | Compares current merchant offers for one exact product, separating item price, shipping, and delivered total. | `product_id` from a previous result, optional `postal_code` (a Greek postcode, 10000–85999, for delivered totals), `objective`, `in_stock_only`, `minimum_merchant_rating`, `limit` (1–10) |
| `get_price_history` | Summarises how a product's price moved over time, against its 180-day median. | `product_id`, optional `period_days` (30, 90 or 180) |
All four tools are read-only. They never place orders, create alerts, or read account
data. Results link to a BestPrice product page, never directly to a merchant. Unknown
shipping is reported as unknown, not as free. Search covers safe physical products;
digital goods, services, and age-restricted categories are excluded.
## Protocol details
Measured against the live endpoint on 24 September 2026.
- **Versions.** `initialize` negotiates `2025-11-25`, `2025-06-18`, `2025-03-26`, `2024-11-05`
and `2024-10-07`; a client that asks for any other version is answered with `2025-11-25`.
The `2026-07-28` per-request revision is also served: send the `MCP-Protocol-Version`,
`Mcp-Method` (and, for `tools/call`, `Mcp-Name`) headers, and put
`io.modelcontextprotocol/protocolVersion` and `io.modelcontextprotocol/clientCapabilities` in
every request's `_meta`. A request that names the revision without that envelope is refused
with `-32602`.
- **Stateless.** No `MCP-Session-Id` is issued and none is required; `DELETE` answers `405`.
A `GET` with `Accept: text/event-stream` opens a keep-alive stream, but the server never sends
requests or notifications on it, so a client loses nothing by not opening it.
- **Capabilities.** `tools` and `resources` are available to compatible clients. The
resource surface contains the optional MCP Apps UI at `ui://bestprice/shopping-results-v1.html`,
the server card at `mcp://server-card.json`, and the canonical
`skill://bestprice-shopping/SKILL.md`. On MCP `2026-07-28` the server also declares the
final `io.modelcontextprotocol/skills` extension: `skills/list` and `skills/get` return the
one BestPrice Shopping Skill with its SHA-256 digest and byte size, and `resources/read`
returns the exact markdown bytes. Older clients simply see the Skill as an ordinary resource.
There are no prompts, completions or logging; those methods answer `-32601`.
- **Responses.** A client that accepts both `application/json` and `text/event-stream` gets a
one-event SSE response. `Accept: application/json`, `*/*` or no `Accept` header gets a single
JSON body. Every tool returns `structuredContent` that validates against its `outputSchema`,
plus the same result as text for clients that do not pass structured content to the model.
- **Errors.** An unknown tool is a JSON-RPC error (`-32602`). Invalid arguments and service
failures such as an unknown product are tool results with `isError: true`, so the model can
read and correct them.
- **Limits.** JSON request bodies up to 256 KiB (`413` above that), a 12-second request
deadline, and per-client rate limits answered with HTTP `429`, JSON-RPC error `-32029` and a
`Retry-After` header. JSON-RPC batch arrays are refused with `400`.
- **Browsers.** Desktop, CLI and server-side clients send no `Origin` header and are not
affected. A browser page may call the endpoint from an allowlisted AI-host origin, from
bestprice.gr, or from `localhost` (so MCP Inspector works in direct mode); any other origin
gets `403`.
- **Authentication.** The four shopping tools work without an account. Optional account
linking is scoped to `events:subscribe`; protected-resource metadata is available at
`/.well-known/oauth-protected-resource` and `/mcp/oauth-protected-resource`.
Events remains disabled during end-to-end qualification.
## Developer quick start
Every client below connects to the same endpoint. Detailed, provider-specific
instructions including OpenAI, Grok, GitHub Copilot, and Microsoft Copilot Studio are in
[`docs/provider-setup.md`](docs/provider-setup.md).
### Claude
[Connect BestPrice to Claude](https://claude.ai/customize/connectors?modal=add-custom-connector&connectorName=BestPrice&connectorUrl=https%3A%2F%2Fmcp.bestprice.gr%2Fmcp)
opens the custom-connector flow with the endpoint prefilled. For Claude Code:
```sh
claude mcp add --transport http bestprice-shopping https://mcp.bestprice.gr/mcp
```
The bundled [`.mcp.json`](.mcp.json) is the equivalent project-scoped configuration.
### Cursor
[Add BestPrice to Cursor](https://cursor.com/install-mcp?name=bestprice-shopping&config=eyJ1cmwiOiJodHRwczovL21jcC5iZXN0cHJpY2UuZ3IvbWNwIn0%3D)
shows the decoded configuration before adding it. The [`.cursor-plugin/`](.cursor-plugin/)
directory holds the marketplace plugin and an agent skill.
### VS Code
[Add BestPrice to VS Code](vscode:mcp/install?%7B%22name%22%3A%22bestprice-shopping%22%2C%22type%22%3A%22http%22%2C%22url%22%3A%22https%3A%2F%2Fmcp.bestprice.gr%2Fmcp%22%7D)
### Gemini CLI and Qwen Code
```sh
gemini extensions install https://github.com/TheBestCo/bestprice-mcp
qwen extensions install https://github.com/TheBestCo/bestprice-mcp --consent
```
Both extensions restrict the imported tools to the four listed above.
### Codex, Claude plugins, and Agent Skill hosts
The root [`plugin.json`](plugin.json), [`mcp.json`](mcp.json), and
[`skills/bestprice-shopping/SKILL.md`](skills/bestprice-shopping/SKILL.md) form a portable
Agent Plugins package: the MCP supplies live shopping data and the Skill teaches the host when and
how to route unbranded Greek shopping intent.
Agent-compatible hosts that discover repository-local skills under `.agents/skills/` get the
same canonical workflow at [`.agents/skills/bestprice-shopping/SKILL.md`](.agents/skills/bestprice-shopping/SKILL.md). [`.codex-plugin/`](.codex-plugin/) remains the
Codex compatibility manifest. [`.claude-plugin/plugin.json`](.claude-plugin/plugin.json) plus the
same root Skill and [`.mcp.json`](.mcp.json) also make this repository a Claude plugin package.
### Self-hosted plugin marketplaces
The same repository can be added directly as a plugin marketplace, with no copied tool or Skill logic:
```sh
copilot plugin marketplace add TheBestCo/bestprice-mcp
copilot plugin install bestprice-shopping@bestprice
claude plugin marketplace add TheBestCo/bestprice-mcp
claude plugin install bestprice-shopping@bestprice
```
Copilot reads [`.github/plugin/marketplace.json`](.github/plugin/marketplace.json) and, under
Agent Plugins 1.0, loads the canonical root `plugin.json`, `mcp.json`, and
`skills/bestprice-shopping/SKILL.md`. Claude reads
[`.claude-plugin/marketplace.json`](.claude-plugin/marketplace.json) and uses
`.claude-plugin/plugin.json`, `.mcp.json`, and the same root Skill.
### Gemini API, DeepSeek, Z.ai
Runnable examples live in [`examples/`](examples/): the Gemini Interactions API and Genkit,
a DeepSeek Harness plugin entry, and a Z.ai GLM call. Each needs the provider's own API key.
BestPrice needs none.
### Any other MCP client
Add a Streamable HTTP server at `https://mcp.bestprice.gr/mcp`. If the host only supports
stdio servers, use the bridge in this repository:
```sh
git clone https://github.com/TheBestCo/bestprice-mcp.git && cd bestprice-mcp
npm ci
node stdio.mjs
```
The bridge forwards everything to the public endpoint and accepts two environment
variables: `BESTPRICE_MCP_URL` (default: the public endpoint) and
`BESTPRICE_MCP_TIMEOUT_MS` (default: 60000). A `Dockerfile` builds the same bridge for
[Glama](https://glama.ai/mcp/servers/TheBestCo/bestprice-mcp) and similar hosts.
## A safe first conversation
1. Ask for a decision: `Θέλω κινητό έως 500 ευρώ με NFC και 5G υποχρεωτικά.`
(I want a phone up to 500 euros, NFC and 5G required.)
2. Or search: `Find Sony WH-1000XM5 under 300 euros.`
3. Pass a returned `product_id` to `compare_offers` with postal code `10558`.
4. Pass the same `product_id` to `get_price_history` for 180 days.
Queries work in Greek or English. Result summaries, catalog data and merchant names come back in Greek.
| Search | Compare offers | Price history |
| --- | --- | --- |
|  |  |  |
## Browser-native WebMCP
BestPrice pages register 22 contextual WebMCP tools (contract 2.8) in compatible browsers — each one
reads or acts, never both — covering search with structured results (narrowed by price, stock, deals and
order) and opening the results page a search returned in the tab, the shopper's shopping list and
comparisons (read everywhere, added to and removed from on a product page), a price-drop alert dialog, the visible products and loading more, filters and sorting,
opening any product by id (read before the tab moves), product facts, offers, specifications and price
history (with its chart), one visible-offer action, and the BestPrice Shopping Brain — on every public
page, articles and stores included — while leaving the merchant choice to the shopper. Every tool publishes an input and an output
schema. The contracts, fail-closed runtime, deterministic evaluator, and the 47-case natural-language
dataset are in [`webmcp/`](webmcp/).
## Discovery
- [Official MCP Registry](https://registry.modelcontextprotocol.io/v0.1/servers?search=gr.bestprice%2Fmcp)
- Open agent discovery: [`ard.json`](https://www.bestprice.gr/.well-known/ard.json),
[`ai-catalog.json`](https://www.bestprice.gr/.well-known/ai-catalog.json),
[server card](https://mcp.bestprice.gr/mcp/server-card), and the
provider-neutral [BestPrice Shopping skill](skills/bestprice-shopping/SKILL.md).
The ARD examples are deliberately unbranded shopper intents so discovery can match
“what should I buy?”, delivered-price, and price-timing requests before a user knows BestPrice.
- [`webmcp.json`](https://www.bestprice.gr/.well-known/webmcp.json) describes the contextual
browser tools exposed by BestPrice pages.
- The repository is listed in the [Gemini CLI extension gallery](https://geminicli.com/extensions/?name=TheBestCobestprice-mcp)
as `bestprice-shopping` (Google crawls tagged public extension repositories), while GitHub Agent Finder
can ingest the public MCP catalog and ARD resources.
- Copy-ready, CI-pinned external catalog contributions live under [`distribution/`](distribution/):
a GitHub Agent Finder Skill entry and a Docker MCP Registry remote-server entry. Those catalogs
require review in their own repositories; the checked-in files are submission payloads, not claims
that the external listings are already live.
- Community indexes: [Glama](https://glama.ai/mcp/servers/TheBestCo/bestprice-mcp),
[WebMCP Registry](https://webmcp-registry.dev/domain/www.bestprice.gr),
[webmcp.com](https://webmcp.com/sites/bestprice.gr),
[cursor.directory](https://cursor.directory/plugins/bestprice-shopping)
## Development
```sh
npm ci
npm run check # Biome lint and format
npm test # node --test: bridge, WebMCP, manifests, dataset
```
Tests need no network: the bridge is exercised against an in-process fake remote. Node 20
or newer is required; `.nvmrc` pins 22.
## Versioning
Two versions appear in this repository on purpose:
- **Package version** in `package.json` and every plugin or extension manifest. It changes
when this repository's manifests, bridge, or WebMCP layer change, and is tagged `vX.Y.Z`.
- **Server version** in `server.json` and the line near the top of this README. It is the
version the hosted service reports and is published to the official MCP Registry.
`CHANGELOG.md` tracks the package version.
Timestamped hosted-service checks are recorded separately. The
[7 September Shopping Brain v12 verification](docs/releases/2026-09-07-brain-v12.md)
includes its exact gateway revision, sanitized canary results, and scope limits.
## Security
Report vulnerabilities privately as described in [`SECURITY.md`](SECURITY.md).
## Contributing
See [`CONTRIBUTING.md`](CONTRIBUTING.md). Issues and pull requests are welcome.
## License
Apache License 2.0. Copyright The Best Company S.A. See [`LICENSE`](LICENSE).
Privacy: <https://www.bestprice.gr/policies/privacy> · Terms: <https://www.bestprice.gr/policies/terms>
TDQS
A4.6/5.0
Scored across 4 tools
Disambiguation5/5
Each tool targets a completely different stage of the shopping workflow: get_shopping_decision for recommendations/plans, search_products for product discovery, compare_offers for current merchant pricing, and get_price_history for historical trends. The long descriptions explicitly state when to use and not use each tool, leaving no ambiguity about which one to select.
Naming Consistency4/5
The names follow a clear verb_noun pattern, but the verbs are mixed: get_shopping_decision and get_price_history share 'get_', while search_products and compare_offers use different verbs. This is still readable and predictable, but not perfectly uniform; minor deviation from a single convention.
Tool Count5/5
Four tools is well within the ideal 3–15 range and each one earns its place. The server is tightly scoped to the shopping assistance domain with no redundant or filler tools, and every tool addresses a distinct consumer need.
Completeness4/5
The surface covers the core shopping journey: search for products, get a recommendation/plan, compare offers, and check price history. A minor gap is the lack of a direct get-product-by-ID tool, but search_products can retrieve product info by name/barcode and compare_offers works with an exact ID, so agents can work around this. Other excluded actions like checkout are intentionally out of scope.
Maintenance
ActivityActive
ResponsivenessNo issues