install.packages("remotes")
remotes::install_github("paleolimbot/qgisprocess")

library(qgisprocess)
qgis_path()
[1] "qgis_process"

# check QGIS version
qgis_version()
[1] "3.14.16-Pi"

# check available QGIS algorithms
qgis_algorithms()
# A tibble: 984 x 5
   provider provider_title algorithm                  algorithm_id          algorithm_title          
   <chr>    <chr>          <chr>                      <chr>                 <chr>                    
 1 3d       QGIS (3D)      3d:tessellate              tessellate            Tessellate               
 2 gdal     GDAL           gdal:aspect                aspect                Aspect                   
 3 gdal     GDAL           gdal:assignprojection      assignprojection      Assign projection        
 4 gdal     GDAL           gdal:buffervectors         buffervectors         Buffer vectors           
 5 gdal     GDAL           gdal:buildvirtualraster    buildvirtualraster    Build virtual raster     
 6 gdal     GDAL           gdal:buildvirtualvector    buildvirtualvector    Build virtual vector     
 7 gdal     GDAL           gdal:cliprasterbyextent    cliprasterbyextent    Clip raster by extent    
 8 gdal     GDAL           gdal:cliprasterbymasklayer cliprasterbymasklayer Clip raster by mask layer
 9 gdal     GDAL           gdal:clipvectorbyextent    clipvectorbyextent    Clip vector by extent    
10 gdal     GDAL           gdal:clipvectorbypolygon   clipvectorbypolygon   Clip vector by mask layer
# … with 974 more rows

# show help on a sample algorithm
qgis_show_help("native:dissolve")
Dissolve (native:dissolve)

----------------
Description
----------------
This algorithm takes a vector layer and combines their features into new features. One or more attributes can be specified to dissolve features belonging to the same class (having the same value for the specified attributes), alternatively all features can be dissolved in a single one.

All output geometries will be converted to multi geometries. In case the input is a polygon layer, common boundaries of adjacent polygons being dissolved will get erased.

----------------
Arguments
----------------

INPUT: Input layer
	Argument type:	source
	Acceptable values:
		- Path to a vector layer
FIELD: Dissolve field(s)
	Argument type:	field
	Acceptable values:
		- The name of an existing field
		- ; delimited list of existing field names
OUTPUT: Dissolved
	Argument type:	sink
	Acceptable values:
		- Path for new vector layer

----------------
Outputs
----------------

OUTPUT: <outputVector>
	Dissolved

library(sf)

# load input file
input_file <- sf::read_sf("/home/bnhr/rdata/vectors/bicol-provinces.shp")
# plot input file
plot(sf::st_geometry(input_file))

# create temp output file
output_file <- file.path(tempdir(), "bicol-dissolved.gpkg")

# run QGIS dissolve algorithm
qgis_run_algorithm(
    "native:dissolve",
    INPUT = input_file,
    FIELD = "[]",
    OUTPUT = output_file
    )

output_sf <- sf::read_sf(output_file)

# plot output (dissolved features)
plot(sf::st_geometry(output_sf))