Our valuation error, forward-validated monthly
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 call over REST
Valuation accuracy/v1/valuation/accuracyNot connected yet? Connect your assistant. Sign in with your MarketCode account; no API key needed.
Inputs
Arguments valuation_accuracy takes
| Name | Type | Required | Description |
|---|---|---|---|
| asset_class | string | No | |
| model_version | string | No | |
| since | string | No |
Usage
How to run valuation_accuracy in your assistant
Ask your assistant in plain English, for example:
"Use the MarketCode tool valuation_accuracy for <address or area>.
Show the result and the credits charged."The connect steps for Claude, ChatGPT, Codex, Cursor and Claude Code are on the MCP page.
Price and licence
What it costs, and where the data comes from
valuation_accuracy 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
Tools used with valuation_accuracy
- 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by the district index to today, any relisting penalty (pass `relisted_uprns` for comps known to have been relisted and withdrawn — each takes a deterministic -10%), and the IQR fence that decided which comps count.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 - The property's own sale, carried to todayFree
subject_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 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_accuracy
How much does `valuation_accuracy` cost?
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valuation_accuracy 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.
Which assistants can run `valuation_accuracy`?
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Any MCP client: Claude (claude.ai, Claude Desktop, Claude Code), ChatGPT in developer mode, Codex and Cursor, each documented on the MCP page. You sign in with your MarketCode account over OAuth; there is no key to paste, and the connection is read-only.
Where does the data come from?
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The answer is computed by MarketCode. Coverage is the UK.
Does `valuation_accuracy` 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_accuracy in your assistant.
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