Yappman Data Supermarket Price Snapshots
REMOTE · YAPPMAN-GROCERY-MCP.BLUE-BAR-CA29.WORKERS.DEV
Read-only UK/AU supermarket price index and UK basket snapshots. CC BY 4.0. Not live prices.
Available components
Last scanned (20 hours ago)
Scores higher than 57% of remote servers
Reachable. Last reached 4 Nov 2026.
Category Finance and Payments
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability69
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 1013 tokens (~202/item across 5 items; 5 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management40
- Stability observed for 12 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 4 Nov 26 0
- The server rewrote its instructions, which are the text every model session reads security
- Tool “about_the_data” rewrote its description, which is the text the model reads security
- Tool “get_shelf_price_index” rewrote its description, which is the text the model reads security
- Tool “list_basket_products” rewrote its description, which is the text the model reads security
- Tool “list_index_vintages” rewrote its description, which is the text the model reads security
- Tool “lookup_basket_prices” rewrote its description, which is the text the model reads security
- 3 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.
- 1 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.
- 30 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.
- 27 Oct 26 +1
- The server rewrote its instructions, which are the text every model session reads security
- Tool “lookup_basket_prices” rewrote its description, which is the text the model reads security
- Schema quality: 743 → 1000 ▼ functional
- MCP protocol: fail → pass ▲ functional
- MCP protocol version: 2025-06-18 → 2025-11-25 functional
- Server version: 0.2.4 → 0.2.5 functional
- Server version: 0.2.3 → 0.2.4 functional
- Server version: 0.2.1 → 0.2.3 functional
- New tool “list_basket_products” functional
- 26 Oct 26 +1
- Tool “lookup_basket_prices” rewrote its description, which is the text the model reads security
- Server version: 0.1.0 → 0.2.1 functional
- 24 Oct 26 +1
- Stability: unverified → 0.03 ▲ functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 4 Nov 2026 · Probed https://yappman-grocery-mcp.blue-bar-ca29.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=blue-bar-ca29.workers.dev | CN=WE1,O=Google Trust Services,C=US | 21 Oct 2026 | 19 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | ed36eff9d2fb5e251354635a67f524ca |
| SANs: blue-bar-ca29.workers.dev, *.blue-bar-ca29.workers.dev | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of yappman-grocery-mcp.blue-bar-ca29.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| workers.dev. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| x-content-type-options | nosniff |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://yappman-grocery-mcp.blue-bar-ca29.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://yappman-grocery-mcp.blue-bar-ca29.workers.dev/mcp | Inconclusive | 405 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
about_the_data Licence, coverage and limits of the data ~71
Returns the licence (CC BY 4.0) and credit form, what is not served, the store setting, the published index weeks and the basket date range with its short and missing days. The licence covers our compilation only, not retailer content. Call it before citing or relying on the other tools.
Input schema present but exposes no named parameters.
Structured output declared, but exposes no named fields.
No examples provided.
get_shelf_price_index Shelf-price index for one week ~231
Returns one published week of the UK or Australian online shelf-price index: index levels, week-on-week change and matched-product counts by retailer and product class. It measures posted online shelf prices, not prices paid; not a CPI or a government statistic. Index levels are not price levels and do not show which retailer is cheaper. No product names. matched and matchedShare show how many products each row rests on. Omit vintage for the latest week; list_index_vintages gives the others.
| Name | Type | Req | Description |
|---|---|---|---|
| class | string | – | Only rows for this product class id, e.g. "dairy-eggs". |
| market | string | yes | uk or au. Example: "uk". |
| recordType | string | – | Only rows of this kind, e.g. "headline". Omit for all rows. |
| retailer | string | – | Only rows for this retailer id, e.g. "tesco" (UK) or "aldi_au" (AU). |
| vintage | string | – | ISO week, e.g. "2026-W42". Omit for the latest published week. |
| Name | Type | Req | Description |
|---|---|---|---|
| base | string | – | – |
| credit | string | yes | – |
| market | string | yes | – |
| notCpi | boolean | – | – |
| publishedAt | string | – | – |
| revision | integer | – | – |
| rows | array | yes | – |
| title | string | – | – |
| vintage | string | yes | – |
No examples provided.
list_basket_products Product identifiers in the daily basket ~178
Returns the identifiers of the products in the UK daily 212-item basket for one day, sorted, with paging: retailer, retailer product id and barcodes (`ean`, empty where the basket holds none, as for Aldi). No names, brands or prices. Use it to find what lookup_basket_prices can look up.
| Name | Type | Req | Description |
|---|---|---|---|
| date | string | – | Day, e.g. "2026-10-08". Omit for the latest day loaded. |
| limit | integer | – | Products per page, 1 to 100. Omit for 100. |
| offset | integer | – | Products to skip, from 0. Use nextOffset from the previous page. Example: 100. |
| retailers | array | – | Only these retailers, e.g. ["tesco", "asda"]. Omit for all four. |
| Name | Type | Req | Description |
|---|---|---|---|
| credit | string | yes | – |
| date | string | yes | – |
| nextOffset | integer|null | yes | – |
| offset | integer | yes | – |
| products | array | yes | – |
| total | integer | yes | – |
No examples provided.
list_index_vintages Published weeks of the shelf-price index ~78
Lists the published weeks (vintages) of the UK or Australian online shelf-price index, newest first, with publication time, revision and base week. Returns no index values and no prices. Use it to choose a week for get_shelf_price_index.
| Name | Type | Req | Description |
|---|---|---|---|
| market | string | yes | uk or au. Example: "au". |
| Name | Type | Req | Description |
|---|---|---|---|
| market | string | yes | – |
| vintages | array | yes | – |
No examples provided.
lookup_basket_prices Daily basket prices by barcode or product id ~268
Returns shelf-price snapshot values from the UK daily 212-item basket for up to 20 barcodes (EAN) or retailer product ids, one day, up to one row per retailer: price, was-price, loyalty price, unit price, pack size and stock, as posted. Loyalty prices appear in the basket rows only, not in the index values. Static snapshot days, not live, not a price comparison, not a statement of which retailer is cheaper. No name search. Aldi has no barcodes: use product ids. Wider data: see about_the_data.
| Name | Type | Req | Description |
|---|---|---|---|
| date | string | – | Day, e.g. "2026-10-08". Omit for the latest day loaded. |
| eans | array | – | Barcodes, 8, 12, 13 or 14 digits, e.g. ["5000157024671"]. Give eans, products or both. |
| products | array | – | Retailer product ids, e.g. [{"retailer": "tesco", "retailerProductId": "254656543"}]. |
| retailers | array | – | Only these retailers, e.g. ["tesco", "asda"]. Omit for all four. The basket holds no barcodes for Aldi: use products for Aldi. |
| Name | Type | Req | Description |
|---|---|---|---|
| credit | string | yes | – |
| date | string | yes | – |
| notFound | object | yes | – |
| rows | array | yes | – |
No examples provided.
How do I install the Yappman Data Supermarket Price Snapshots MCP server?
Yappman Data Supermarket Price Snapshots is a hosted endpoint at https://yappman-grocery-mcp.blue-bar-ca29.workers.dev/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · yappman-grocery-mcp.blue-bar-ca29.workers.dev
claude mcp add --transport http yappmaniac-grocery-price-snapshots 'https://yappman-grocery-mcp.blue-bar-ca29.workers.dev/mcp'
What is the Yappman Data Supermarket Price Snapshots MCP server?
Yappman Data Supermarket Price Snapshots is an MCP server listed in the public MCP registry as io.github.yappmaniac/grocery-price-snapshots. Read-only UK/AU supermarket price index and UK basket snapshots. CC BY 4.0. Not live prices. This page covers its hosted endpoint (https://yappman-grocery-mcp.blue-bar-ca29.workers.dev/mcp).
Is the Yappman Data Supermarket Price Snapshots MCP server safe to use?
Yappman Data Supermarket Price Snapshots scores 71 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the Yappman Data Supermarket Price Snapshots MCP server expose?
Yappman Data Supermarket Price Snapshots exposes 5 tools: get_shelf_price_index, list_index_vintages, lookup_basket_prices, list_basket_products, about_the_data. Their descriptions and schemas cost roughly 826 tokens of context every time the server is loaded.
Does the Yappman Data Supermarket Price Snapshots MCP server require authentication?
No. We connected to Yappman Data Supermarket Price Snapshots without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Yappman Data Supermarket Price Snapshots MCP server still maintained?
Yappman Data Supermarket Price Snapshots is still listed as active in the MCP registry. We last reached this channel on 4 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.