diff --git a/snappy_pipeline/workflows/somatic_variant_annotation/model.py b/snappy_pipeline/workflows/somatic_variant_annotation/model.py
new file mode 100644
index 000000000..44098a9fb
--- /dev/null
+++ b/snappy_pipeline/workflows/somatic_variant_annotation/model.py
@@ -0,0 +1,111 @@
+import enum
+from typing import Annotated
+
+from pydantic import Field
+
+from models import SnappyStepModel, EnumField, SnappyModel
+
+
+class Tool(enum.Enum):
+    jannovar = "jannovar"
+    vep = "vep"
+
+
+class Dbnsfp(SnappyModel):
+    col_contig: int = 1
+    col_pos: int = 2
+    columns: list[str] = []
+
+
+class Jannovar(SnappyModel):
+    path_jannovar_ser: str
+
+    flag_off_target: bool
+
+    dbnsfp: Dbnsfp
+    """configuration for default genome release, needs change if differing"""
+
+    annotation_tracks_bed: list[str] = []
+
+    annotation_tracks_tsv: list[str] = []
+
+    annotation_tracks_vcf: list[str] = []
+
+    window_length: int = 50000000
+    """split input into windows of this size, each triggers a job"""
+
+    num_jobs: int = 100
+    """number of windows to process in parallel"""
+
+    use_profile: bool = True
+    """use Snakemake profile for parallel processing"""
+
+    restart_times: int = 5
+    """number of times to re-launch jobs in case of failure"""
+
+    max_jobs_per_second: int = 10
+    """throttling of job creation"""
+
+    max_status_checks_per_second: int = 10
+    """throttling of status checks"""
+
+    ignore_chroms: list[str] = ["NC_007605", "hs37d5", "chrEBV", "GL*", "*_decoy", "HLA-*"]
+    """patterns of chromosome names to ignore"""
+
+
+class VepTxFlag(enum.Enum):
+    gencode_basic = "gencode_basic"
+    refseq = "refseq"
+    merged = "merged"
+
+
+class Vep(SnappyModel):
+    cache_dir: str = ""
+    """Defaults to $HOME/.vep Not a good idea on the cluster"""
+
+    species: str = "homo_sapiens"
+
+    assembly: str = "GRCh38"
+
+    cache_version: int = 102
+    """WARNING- this must match the wrapper's vep version!"""
+
+    tx_flag: VepTxFlag = VepTxFlag.gencode_basic
+    """The flag selecting the transcripts.  One of "gencode_basic", "refseq", and "merged"."""
+
+    pick_order: list[str] = [
+        "biotype",
+        "mane",
+        "appris",
+        "tsl",
+        "ccds",
+        "canonical",
+        "rank",
+        "length",
+    ]
+    num_threads: int = 8
+    buffer_size: int = 1000
+    output_options: list[str] = ["everything"]
+
+
+class SomaticVariantAnnotation(SnappyStepModel):
+    tools: Annotated[list[Tool], EnumField(Tool, [Tool.jannovar, Tool.vep])]
+
+    path_somatic_variant_calling: Annotated[str, Field(examples=["../somatic_variant_calling"])]
+
+    tools_ngs_mapping: list[str] = []
+    """default to those configured for ngs_mapping"""
+
+    tools_somatic_variant_calling: list[str] = []
+    """default to those configured for somatic_variant_calling"""
+
+    jannovar: Jannovar | None = None
+
+    vep: Vep | None = None
+
+    @model_validator(mode="after")
+    def ensure_tools_are_configured(self):
+        for tool in self.tools:
+            if not getattr(self, str(tool)):
+                raise ValueError(f"Tool {tool} not configured")
+        return self