How to use function layers with query parameters?

[zsoooc]

I want to use the following function layer in MapLibre GL JS that use two parameters (merged to a json).

CREATE OR REPLACE FUNCTION test_function(
	z integer,
	x integer,
	y integer,
	query_params json)
    RETURNS bytea
    LANGUAGE 'plpgsql'
    COST 100
    STABLE
AS $BODY$
     DECLARE
              result bytea;	 
              BEGIN   
                  WITH
                  bounds AS (
                    SELECT public.ST_TileEnvelope(z, x, y) AS geom
                  ),
                  mvtgeom AS (
                    SELECT public.ST_AsMVTGeom(ST_Transform(t.polygon, 3857), bounds.geom) AS geom, *
                    FROM shpdata t, bounds
                    WHERE t.date_start > (query_params->>'date_start')::timestamp without time zone AND t.date_start < (query_params->>'date_end')::timestamp without time zone
                                    AND ST_Intersects(t.polygon,ST_Transform(bounds.geom, 4326))
                  )
                  SELECT ST_AsMVT(mvtgeom.*, 'default')
                  INTO result
                  FROM mvtgeom;
                  RETURN result;
              END;  
$BODY$;

This function is works if I run it in PgAdmin.

SELECT test_function(
    9, 262, 172,
    '{
        "date_start":"2025-10-31T14:20:00",
        "date_end":"2025-11-04T11:08:00"
    }'::json)

However, I can not run it from browser, I tried this:

http://127.0.0.1:6767/test_function/9/262/172?query_params=%7B%22date_start%22%3A%222025-10-31T14%3A20%3A00%22%2C%22date_end%22%3A%222025-11-04T11%3A08%3A00%22%7D

I got "Not found" error.

How can I solve this problem?

This function layer is on the list at: , so I think the Martin recognises this layer. Other function layers that contains only x,y,z arguments are work perfectly. The problem is if I want to use extra arguments.

[CommanderStorm]

Not found

This can be multiple things:

• there is a typo in the functions name (see /catalog or the webui for all avaliable names) or
• it is not discovered (See the log shown at startup)

Tip

the url query params are the following instead:

GET http://127.0.0.1:6767/test_function/9/262/172?date_start=31T14:20:00&date_end=2025-11-04T11:08:00

Tip

Our pg functions docs contain a few attributes regarding paralell safety, ...

[zsoooc]

Unfortunately, the docs doesn't contain example how to call the function from browser. There is an only an example of a PostGIS function.

I checked the LOG:
[2025-11-05T14:16:35Z INFO martin::config::file::tiles::postgres::builder] Discovered source test_function from function test_function(integer, integer, integer, json) -> bytea

In the catalog:
"test_function":{"content_type":"application/x-protobuf","description":"test_function"}

I tried with this:
http://127.0.0.1:6767/test_function/9/262/172?date_start=31T14:20:00&date_end=2025-11-04T11:08:00

It works! Thanks!

[CommanderStorm]

Unfortunately, the docs doesn't contain example how to call the function from browser. There is an only an example of a PostGIS function.

Sorry, I don't get this.
What docs are missing?