qgis-processing

id qgis-processing name QGIS Processing description Use Arion's local QGIS integration to discover, describe, and run qgis_process workflows against file-backed layers. Use when a request involves QGIS Processing algorithms, qgis_process troubleshooting, chaining multiple QGIS steps, or selecting the right algorithm and parameters for a map layer. QGIS Processing When To Use Use when the request explicitly mentions QGIS, qgis_process , or Processing algorithms. Use when a map layer needs a QGIS algorithm such as buffer, clip, dissolve, extract, field calculation, reprojection, or layout export. Use when a multi-step workflow needs chained QGIS outputs instead of a single one-off run. Workflow List map layers first when the user refers to a layer already on the map. Use integrationInputs.qgis.inputPath from the layer listing when available. Fall back to localFilePath only for file-backed layers. Search algorithms with qgis_list_algorithms using a focused query , an optional provider , and a small limit . Prefer provider: native first. For compound tasks, search the immediate step you need next instead of the whole workflow at once. Describe the shortlisted algorithm with qgis_describe_algorithm before building parameters. Run the algorithm with qgis_run_processing using the exact parameter names from the description. For final outputs, use a simple named file such as buffer.geojson , result.gpkg , or warped.tif and let Arion manage the output workspace. Chain multi-step workflows by feeding returned artifact paths into the next QGIS run. After each run, inspect result , artifacts , and importedLayers before deciding the next step. Guardrails Do not guess algorithm ids from memory when qgis_list_algorithms and qgis_describe_algorithm can confirm them. Do not use arbitrary absolute output paths for generated files unless they are already inside Arion's managed QGIS workspace. Prefer relative output filenames. Do not rely on TEMPORARY_OUTPUT for a final result that should appear on the map. Use a named output file instead. Prefer approved native:* algorithms. Treat non- native algorithms as suspect until the tool response confirms they are allowed. For feature-inspection tasks, prefer extraction or transformation workflows that produce a concrete vector or table output the app can import and preview. Search Hints Search buffer , clip , dissolve , reproject , extract , field , order , sort , geometry , layout , translate , or warp instead of requesting the full algorithm catalog. If the first search is too broad, narrow by provider or add a second keyword such as extract expression or field calculator . For requests like top 10 longest lines , search sort line features by length or order by expression first, then search the extraction or retention step separately.