diff --git a/dap/algos/__init__.py b/dap/algos/__init__.py
index d5e8f0b..b70958a 100644
--- a/dap/algos/__init__.py
+++ b/dap/algos/__init__.py
@@ -2,6 +2,7 @@
 from .addmask import calc_apply_additional_mask
 from .addmaskfile import calc_apply_additional_mask_from_file
 from .aggregation import calc_apply_aggregation
+from .custom import calc_custom
 from .jfdata import JFData
 from .mask import calc_mask_pixels
 from .peakfind import calc_peakfinder_analysis
diff --git a/dap/algos/custom.py b/dap/algos/custom.py
new file mode 100644
index 0000000..214c7eb
--- /dev/null
+++ b/dap/algos/custom.py
@@ -0,0 +1,64 @@
+import functools
+import importlib.util as ilu
+from pathlib import Path
+
+
+BASE = "/gpfs/photonics/swissfel/buffer/dap/custom_dap_scripts"
+BASE = Path(BASE)
+
+
+def calc_custom(results, image, pixel_mask):
+    script = results.get("custom_script")
+    if not script:
+        return
+
+    try:
+        func = load_custom(script)
+        res = func(results, image, pixel_mask)
+    except Exception as e:
+        en = type(e).__name__
+        error = f"{en}: {e}"
+        return {"custom_script_error": error}
+
+    if isinstance(res, dict):
+        res = {f"{script}:{k}": v for k, v in res.items()}
+    else:
+        res = {script: res}
+
+    results.update(res)
+
+
+@functools.cache
+def load_custom(script):
+    beamline, name = script.split(":")
+
+    ext = ".py"
+    if not name.endswith(ext):
+        name += ext
+
+    fn = BASE / beamline / name
+    return load_proc(fn)
+
+
+def load_proc(fn):
+    mod = load_module(fn)
+
+    proc_func_name = "proc"
+    mod_name = mod.__name__
+
+    func = getattr(mod, proc_func_name, None) or getattr(mod, mod_name, None)
+    if func is None:
+        raise AttributeError(f'module "{mod_name}" contains neither "{proc_func_name}" nor "{mod_name}" function')
+
+    return func
+
+
+def load_module(file_path, module_name=None):
+    module_name = module_name or Path(file_path).stem
+    spec = ilu.spec_from_file_location(module_name, file_path)
+    module = ilu.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+
diff --git a/dap/worker.py b/dap/worker.py
index 9df29c8..2b96866 100644
--- a/dap/worker.py
+++ b/dap/worker.py
@@ -5,7 +5,7 @@ import numpy as np
 from logzero import logger as log
 
 from algos import (
-    calc_apply_aggregation, calc_apply_threshold, calc_mask_pixels, calc_peakfinder_analysis,
+    calc_apply_aggregation, calc_apply_threshold, calc_custom, calc_mask_pixels, calc_peakfinder_analysis,
     calc_radial_integration, calc_roi, calc_spi_analysis, calc_streakfinder_analysis, JFData
 )
 from utils import Aggregator, BufferedJSON, make_bsread_timestamp, randskip, read_bit
@@ -123,6 +123,7 @@ def work(backend_addr, accumulator_addr, visualisation_addr, fn_config, skip_fra
         calc_roi(results, pfimage)
         calc_spi_analysis(results, pfimage)
         calc_peakfinder_analysis(results, pfimage, pixel_mask)
+        calc_custom(results, pfimage, pixel_mask)
 
         # streak finder for convergent-beam diffraction experiments
         # changes image and pixel_mask in place if do_snr=True in parameters file