Layer operations
Buffer features by a distance
A buffer of a given width around each feature of a layer, or one merged area whose overlaps count once, as a GIS file.
| REST | POST https://mcp.terra-lab.ai/v1/tools/buffer_features |
| MCP tool | buffer_features on https://mcp.terra-lab.ai/mcp |
| Group | Layer operations |
Request
curl -X POST https://mcp.terra-lab.ai/v1/tools/buffer_features \
-H "Authorization: Bearer $TERRALAB_API_KEY" \
-H "Content-Type: application/json" \
-d '{"geojson":{"type":"LineString","coordinates":[[6.12,45.9],[6.13,45.905]]},"radius_m":200}'
import os
import requests
response = requests.post(
"https://mcp.terra-lab.ai/v1/tools/buffer_features",
headers={"Authorization": f"Bearer {os.environ['TERRALAB_API_KEY']}"},
json={
"geojson": {
"type": "LineString",
"coordinates": [[6.12, 45.9], [6.13, 45.905]],
},
"radius_m": 200,
},
timeout=120,
)
response.raise_for_status()
print(response.json()["structuredContent"])
const response = await fetch('https://mcp.terra-lab.ai/v1/tools/buffer_features', {
method: 'POST',
headers: {
Authorization: `Bearer ${process.env.TERRALAB_API_KEY}`,
'Content-Type': 'application/json',
},
body: JSON.stringify({
"geojson": {
"type": "LineString",
"coordinates": [
[
6.12,
45.9
],
[
6.13,
45.905
]
]
},
"radius_m": 200
}),
});
const data = await response.json();
console.log(data.structuredContent);
Parameters
A JSON object in the request body; in an MCP client, the arguments of the tool call.
| Name | Type | Required | Description |
|---|---|---|---|
file | object | No | A file uploaded in the conversation (GeoJSON, KML, KMZ, GPX, zipped Shapefile, CSV or WKT). |
file.download_url | string | Yes | |
file.file_id | string | Yes | |
file.file_name | string | No | |
file.mime_type | string | No | |
url | string | No | A public http(s) link to the features, or a TerraLab download link from an earlier answer. |
geojson | object | No | The features as a GeoJSON FeatureCollection, Feature or geometry in WGS 84 (longitude, latitude). |
radius_m | number | Yes | The buffer distance in metres (convert km or miles first). From 0.1 to 100000. |
dissolve | boolean | No | Merge all buffers into one feature, so overlaps count once in the total area. |
formats | array of string | No | Download formats. All five by default. |
title | string | No | Name for the map and the output files. |
Response
structuredContent holds the result, content the same result as text for a model, and isError is true when the tool refused the request or failed; then structuredContent.code, message and hint say what to change.
{
"structuredContent": {
"sources": [{ "name": "...", "licence": "...", "url": "..." }],
"downloads": [{ "label": "...", "format": "...", "url": "...", "name": "..." }]
},
"content": [{ "type": "text", "text": "..." }],
"isError": false
}
Every result lists its sources with their licence. File results come as downloads: each link builds its file when opened.
Errors
A missing key answers 401, an empty balance 402, too many calls 429. A call that fails or finds nothing is not counted. See Errors and rate limits.
Description for agents
The text the server gives an agent to decide when to call this tool:
Use this when the user wants a buffer (zone of a given width) around features or a drawn line or polygon: an uploaded file, a link, inline GeoJSON, or a download link from another TerraLab answer. Each feature gets its own buffer polygon, or with dissolve one merged area whose overlaps count once, built in a local equidistant projection; up to 25,000 vertices. Returns the feature count, total area, a map and GeoJSON, KML, Shapefile zip, GeoPackage and CSV downloads. Not for a circle around one place (circle_around_place). Never use the user's current location unless they type it. Download links build their file when opened; no file is saved. The user opens the file in QGIS or any GIS: this server cannot load it into the user's own QGIS or any app on their computer. Never pass these links to open_gis_file: list every format the user needs in formats, in this one call. TerraLab reads the file or link to answer and keeps no copy.
Updated 2026-11-15