Valuation transaction anchor
GET /v1/valuation/{uprn}/transaction-anchorThe property's own last registered sale carried to today by the district index: the price paid, the date, the index factor applied and the anchored value. Where a property has sold, this is the strongest single piece of evidence a valuation has. Returns an empty anchor when no registered sale is linked to the UPRN. UK only.
Same call over MCP
The property's own sale, carried to todaysubject_transaction_anchorAuthenticate with an API key from the API & MCP Hub. The same call is available as an MCP tool at the same price.
Inputs
Before you call it
- uprn
- A UPRN is the Unique Property Reference Number every UK address carries. Narrow the address with address_autocomplete, which is free, then address_resolve returns the UPRN for 8 credits. property_summary and address_by_postcode return UPRNs too.
Request
Calling GET /v1/valuation/{uprn}/transaction-anchor
curl "https://api.marketcode.ai/v1/valuation/200003448393/transaction-anchor" \
-H "Authorization: Bearer $MARKETCODE_API_KEY"Send your API key as a Bearer token. Every response carries credits_charged and credits_remaining.
Inputs
Parameters
| Name | In | Type | Required | Description |
|---|---|---|---|---|
| uprn | Path | integer | Yes | Property UPRN |
Price and licence
What it costs, and where the data comes from
Valuation transaction anchor is free over MCP and over REST, and the two surfaces share one credit balance. Free calls need a signed-in account or an API key and appear in your usage, but they never touch your balance.
Credits are granted on sign-up and bought in packs; the pricing page lists every call.
Related
Endpoints used with Valuation transaction anchor
- Comparables with their time adjustments2 credits
comps_adjustmentsThe evidence behind a valuation, itemised: same-building comparable sales for the property, each with its registered price and date, the time adjustment by the district index to today, any relisting penalty (pass `relisted_uprns` for comps known to have been relisted and withdrawn — each takes a deterministic -10%), and the IQR fence that decided which comps count. Use it to show WHY a value is what it is; `valuation_full` gives the value itself. `lookback_months` 12–120. UK only.Same category - Our valuation error, forward-validated monthlyFree
valuation_accuracyHow accurate our valuations have been, measured the only way that cannot leak: each month, every registered sale the model had ALREADY valued is compared with the price actually paid — MdAPE (median absolute percentage error), PPE20 (share within 20%) and n, per asset class and model version. Until the first vintage lands in October 2026 the answer is `status: no_rows_yet` with the metric definitions: an empty table, not a zero error. Filters: `asset_class` (Residential | Commercial | Mixed-Use), `model_version` (e.g. gbm-h3-v4), `since` (YYYY-MM). UK only.Same category - Automated valuation estimateFree
valuation_estimateAutomated value estimate for a property: a point value plus a range.Same category - Full valuation with back-seriesFree
valuation_fullFull valuation block for a property: the value and its range, a monthlySame category
FAQ
Questions about Valuation transaction anchor
How much does `subject_transaction_anchor` cost?
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Valuation transaction anchor is free over MCP and over REST, and the two surfaces share one credit balance. Free calls need a signed-in account or an API key and appear in your usage, but they never touch your balance.
Do I need to resolve the address first?
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Yes. subject_transaction_anchor takes a UPRN, not an address. Start with address_autocomplete (free) to narrow the address, then address_resolve (8 credits) to get the UPRN. An assistant with the MarketCode skills installed does both steps on its own.
How do I authenticate?
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Send your API key as a Bearer token in the Authorization header. Keys are created in the API & MCP Hub, shown once and revocable. Every response carries the credits charged and your remaining balance.
Is there an MCP version?
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Yes. The subject_transaction_anchor tool on the MarketCode MCP server is the same call at the same price, signed in with OAuth rather than a key, so Claude, ChatGPT, Codex and Cursor can run it in a conversation.
Where does the data come from?
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The answer is computed by MarketCode. Coverage is the UK.
Does `subject_transaction_anchor` change anything?
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No. The tool is annotated read-only on the server, so it never writes to your data or ours and an assistant can call it without a confirmation step.
Try Valuation transaction anchor on a real address.
30-minute call. We'll provision a key and walk through the endpoint on your use case.