Unique API key from Altum. Obtain one via Mopsus (https://mopsus.altum.ai)
This is the main endpoint of the API. It retrieves a list of subsidies based on a user's postcode and, if provided, their personal and financial details for loan eligibility checking.
**`GET`** `https://api.altum.ai/market-trend?postcode=??`
### Request body
**Market Trend Request Model**
| **Field** | **Type** | **Description** |
| ------------------------------------------ | -------- | --------------------------------------------------- |
| postcode\* | string | **Required**. The Dutch postcode (e.g., "3511 AA"). |
**Example Complete Input**
```
https://api.altum.ai/market-trend?postcode=5258BB
```
Upon a successful `GET` request, the API returns a `200 OK` status with a JSON object containing the results.
### Market Trend API Response Model
| **Field** | **Type** | **Description** |
| ------------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------- |
| postcode | String | The normalized Dutch postcode (e.g., "1011AB") used for the query. |
| city | String | The city name derived from the master address database. |
| neighbourhood | String | The specific neighborhood name (if available in Dataland source). |
| municipality | String | The administrative municipality governing the area. |
| averagePriceSingleFamilyHomes | Float | The average transaction price for single-family properties (detached, semi-detached, terraced). |
| averagePriceMultiFamilyHomes | Float | The average transaction price for multi-family properties (apartments/flats). |
| pricePerSquareMeterSingleFamily | Float | The average price per square meter (€/m²) for single-family homes. |
| pricePerSquareMeterMultiFamily | Float | The average price per square meter (€/m²) for apartments. |
| annualPriceChange | Float | The annualized percentage growth (CAGR) of property values compared to the previous recorded year. |
| fiveYearPriceChange | Float | The projected percentage change in value over a 5-year period based on historical growth trends. |
| totalSalesLast12Months | Integer | The total count of property transactions recorded in this postcode over the last 365 days. |
| priceDistribution | Object | A dictionary serving as a histogram, mapping price ranges (e.g., "250-500k") to the number of properties sold in that bracket. |
| pricePerSquareMeterDistribution | Object | A dictionary serving as a histogram, mapping price-per-m² ranges (e.g., "3000-3500") to the frequency of sales in that bracket. |
### Output
Upon a successful `GET` request, the API returns a `200 OK` status with a JSON object containing the results.
**Example Complete Output**
```
{
"region": {
"postcode": "5258BB",
"city": "BERLICUM NB",
"neighbourhood": "Berlicum",
"municipality": "Sint-Michielsgestel"
},
"averagePriceSingleFamilyHomes": 681870.58,
"averagePriceMultiFamilyHomes": null,
"pricePerSquareMeterSingleFamily": 1035.61,
"pricePerSquareMeterMultiFamily": null,
"annualPriceChange": 6.67,
"fiveYearPriceChange": 38.09,
"transactionData": {
"totalSalesLast12Months": 0
},
"priceDistribution": {
"250-500k": 2,
"500-750k": 4,
"1M+": 2
},
"pricePerSquareMeterDistribution": {
"0-2500": 8
}
}
```
**Explanation**
🏘️ **Region**
```
"region": {
"postcode": "5258BB",
"city": "BERLICUM NB",
"neighbourhood": "Berlicum",
"municipality": "Sint-Michielsgestel"
}
```
{% hint style="info" %}
All the data and KPIs are calculated for postcode 5258BB, providing context at the city **BERLICUM NB**, neighborhood **Berlicum**, and municipality **Sint-Michielsgestel**.
{% endhint %}
💰 **Average Property Prices**
```
"averagePriceSingleFamilyHomes": 681870.58,
"averagePriceMultiFamilyHomes": null
```
{% hint style="info" %}
* **Single-family homes:** €681,870 on average.
* **Multi-family homes / apartments:** No data available for this area.
This tells us that houses in this postcode are relatively expensive, and the market for apartments is either very small or not recorded.
{% endhint %}
📏 **Price Per Square Meter**
```
"pricePerSquareMeterSingleFamily": 1035.61,
"pricePerSquareMeterMultiFamily": null
```
{% hint style="info" %}
* **Single-family homes:** €1,035 per m².
* **Multi-family homes:** No data available.
This gives a way to compare house prices fairly, even if the sizes of the houses differ.
{% endhint %}
📈 **Price Trends**
```
"annualPriceChange": 6.67,
"fiveYearPriceChange": 38.09
```
{% hint style="info" %}
* **Annual price change:** +6.7% → prices increased over the last year.
* **Five-year price change:** +38.1% → prices increased significantly over the last 5 years.
This shows that house prices are rising in both the short term and long term.
{% endhint %}
🏷️ **Transaction Activity**
```
"transactionData": {
"totalSalesLast12Months": 0
}
```
{% hint style="info" %}
* **Number of sales in the last 12 months:** 0
This means **no houses were sold in this area over the past year**, so the market is currently inactive.
{% endhint %}
💵 **Price Distribution**
```
"priceDistribution": {
"250-500k": 2,
"500-750k": 4,
"1M+": 2
}
```
{% hint style="info" %}
* How many houses were sold in each price range (all-time, not just last 12 months):
* €250k–€500k → 2 houses
* €500k–€750k → 4 houses
* €1M+ → 2 houses
Most houses sold in this postcode fall in the **€500k–€750k range**, with a few high-end sales over €1M.
{% endhint %}
🏠 **Price Per Square Meter Distribution**
```
"pricePerSquareMeterDistribution": {
"0-2500": 8
}
```
{% hint style="info" %}
* All 8 recorded sales are in the **0–2,500 €/m² range**.
This tells us that even expensive houses are relatively modest in €/m² compared to very high-end markets.
{% endhint %}
{% tabs %}
{% tab title="200: OK Standard response" %}
```
Request processed and data returned.
```
{% endtab %}
{% tab title="400: Bad Request Unsuccessful response" %}
```
The postcode exists, but there is insufficient data (e.g., missing dates or prices) to calculate KPIs.
```
{% endtab %}
{% tab title="404 Not Found" %}
```
No transactions or master data exist for the provided postcode.
```
{% endtab %}
{% tab title="422 Validation Error" %}
The postcode format was incorrect (e.g., "12345").
{% endtab %}
{% tab title="500: Internal Server Error Service is not available and/or down" %}
```
Database connection failure or unhandled exception in calculation logic.
```
{% endtab %}
{% endtabs %}
---
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```
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```
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The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
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