Site cost index
GET /v1/site/cost-indexConstruction cost index series for a development appraisal's cost side: `basis` is tender (tender price indices), output (output price indices), deflator (the construction deflator) or labour. Optional `sector` (residential, commercial, industrial, infrastructure, all, …), `freq` (monthly | quarterly | annual) and an inclusive period window in the series' own format (2014Q1, 2014M01, 2014). Each series carries its base period and method. UK-wide; regional factors come with the site appraisal. UK only.
Same call over MCP
Construction cost index seriescost_indexAuthenticate 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
- sector
- Sectors follow the VOA classification (OFFICE, RETAIL, INDUSTRIAL_WAREHOUSE, HOTEL and so on). Omit the argument for all sectors; the response names the sectors published for an area when the one you asked for is not.
Request
Calling GET /v1/site/cost-index
curl "https://api.marketcode.ai/v1/site/cost-index?basis=%3Cbasis%3E" \
-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 |
|---|---|---|---|---|
| basis | Query | string | Yes | tender | output | deflator | labour |
| sector | Query | string | No | residential, commercial, industrial, infrastructure, all, … |
| region_key | Query | string | No | Only UK is loaded; regional factors are /site/appraisal's inputsDefault: UK |
| freq | Query | string | No | monthly | quarterly | annual |
| from_period | Query | string | No | Inclusive lower bound, e.g. 2014Q1 / 2014M01 / 2014 |
| to_period | Query | string | No | Inclusive upper bound |
Price and licence
What it costs, and where the data comes from
Site cost index 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 Site cost index
- Site appraisal dossier5 credits
site_appraisalEverything known about ONE site, assembled and judged — the site dossier.Same category - Owners of sourced parcels5 credits
sourcing_ownersResolve registered owners for parcels returned by `sourcing_search`.Same category - Search land or units by criteria8 credits
sourcing_searchFind land parcels or residential units matching investment criteria — the sourcing tool. Give a `location` (place or area name) or a `bbox`.Same category
FAQ
Questions about Site cost index
How much does `cost_index` cost?
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Site cost index 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.
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 cost_index 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 `cost_index` 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 Site cost index on a real address.
30-minute call. We'll provision a key and walk through the endpoint on your use case.