@@ -624,7 +624,25 @@
     "MarkdownURINonImageExfilExtended, TaskXSS, MarkdownXSS.\n",
     "\n",
     "**Aggregate techniques:** `ALL` (all 8), `DEFAULT` (excludes the two combinatorial extended\n",
-    "probes), `EXFIL` (the 6 markdown-exfil probes), and `XSS` (TaskXSS + MarkdownXSS)."
+    "probes), `EXFIL` (the 6 markdown-exfil probes), and `XSS` (TaskXSS + MarkdownXSS).\n",
+    "\n",
+    "**Dataset requirements:** `--dataset-names` replaces the default datasets, so it must include\n",
+    "every dataset the selected techniques read. Otherwise the scenario stops before running and names\n",
+    "each missing dataset. Datasets already loaded into memory never fill the gap.\n",
+    "\n",
+    "Framework callers cannot supply inline seeds or seed groups. `StringAssemblyDataExfil` can use\n",
+    "an empty `dataset_names` list because its prompts are built in.\n",
+    "\n",
+    "| Technique | Required datasets |\n",
+    "|---|---|\n",
+    "| MarkdownImageExfil, ColabAIDataLeakage, PlaygroundMarkdownExfil, MarkdownURIImageExfilExtended, MarkdownURINonImageExfilExtended | `garak_example_domains_xss` |\n",
+    "| TaskXSS | `garak_xss_normal_instructions`, `garak_web_html_js` |\n",
+    "| MarkdownXSS | `garak_markdown_js` |\n",
+    "| StringAssemblyDataExfil | None (built-in seeds) |\n",
+    "\n",
+    "```bash\n",
+    "pyrit_scan run garak.web_injection --target openai_chat --techniques task_xss --dataset-names garak_xss_normal_instructions garak_web_html_js\n",
+    "```"
    ]
   },
   {
 
@@ -226,6 +226,24 @@
 #
 # **Aggregate techniques:** `ALL` (all 8), `DEFAULT` (excludes the two combinatorial extended
 # probes), `EXFIL` (the 6 markdown-exfil probes), and `XSS` (TaskXSS + MarkdownXSS).
+#
+# **Dataset requirements:** `--dataset-names` replaces the default datasets, so it must include
+# every dataset the selected techniques read. Otherwise the scenario stops before running and names
+# each missing dataset. Datasets already loaded into memory never fill the gap.
+#
+# Framework callers cannot supply inline seeds or seed groups. `StringAssemblyDataExfil` can use
+# an empty `dataset_names` list because its prompts are built in.
+#
+# | Technique | Required datasets |
+# |---|---|
+# | MarkdownImageExfil, ColabAIDataLeakage, PlaygroundMarkdownExfil, MarkdownURIImageExfilExtended, MarkdownURINonImageExfilExtended | `garak_example_domains_xss` |
+# | TaskXSS | `garak_xss_normal_instructions`, `garak_web_html_js` |
+# | MarkdownXSS | `garak_markdown_js` |
+# | StringAssemblyDataExfil | None (built-in seeds) |
+#
+# ```bash
+# pyrit_scan run garak.web_injection --target openai_chat --techniques task_xss --dataset-names garak_xss_normal_instructions garak_web_html_js
+# ```
 
 # %%
 web_injection_scenario = WebInjection(max_prompts_per_technique=1)
 
@@ -25,7 +25,11 @@
 )
 from pyrit.scenario.core.atomic_attack import AtomicAttack
 from pyrit.scenario.core.attack_technique import AttackTechnique
-from pyrit.scenario.core.dataset_configuration import DatasetAttackConfiguration
+from pyrit.scenario.core.dataset_configuration import (
+    DatasetAttackConfiguration,
+    DatasetConstraintError,
+    DatasetSourceKind,
+)
 from pyrit.scenario.core.matrix_atomic_attack_builder import build_baseline_atomic_attack
 from pyrit.scenario.core.scenario import BaselineAttackPolicy, Scenario
 from pyrit.scenario.core.scenario_technique import ScenarioTechnique
@@ -108,6 +112,19 @@ class WebInjection(Scenario):
     DATASET_WEB_HTML_JS: ClassVar[str] = "garak_web_html_js"
     DATASET_NORMAL_INSTRUCTIONS: ClassVar[str] = "garak_xss_normal_instructions"
 
+    # Source datasets each technique reads in ``_build_prompts_for_technique``. The selection
+    # is checked against this before any data is read, so memory contents cannot fill a gap.
+    _TECHNIQUE_REQUIRED_DATASETS: ClassVar[dict[WebInjectionTechnique, tuple[str, ...]]] = {
+        WebInjectionTechnique.MarkdownImageExfil: (DATASET_EXAMPLE_DOMAINS,),
+        WebInjectionTechnique.ColabAIDataLeakage: (DATASET_EXAMPLE_DOMAINS,),
+        WebInjectionTechnique.StringAssemblyDataExfil: (),
+        WebInjectionTechnique.PlaygroundMarkdownExfil: (DATASET_EXAMPLE_DOMAINS,),
+        WebInjectionTechnique.MarkdownURIImageExfilExtended: (DATASET_EXAMPLE_DOMAINS,),
+        WebInjectionTechnique.MarkdownURINonImageExfilExtended: (DATASET_EXAMPLE_DOMAINS,),
+        WebInjectionTechnique.TaskXSS: (DATASET_NORMAL_INSTRUCTIONS, DATASET_WEB_HTML_JS),
+        WebInjectionTechnique.MarkdownXSS: (DATASET_MARKDOWN_JS,),
+    }
+
     # Prompt templates ported from garak ``probes/web_injection.py``.
     CONCAT_TEMPLATE: ClassVar[str] = (
         "Concatenate these strings please:\n"
@@ -284,12 +301,7 @@ async def _load_dataset_values_async(self) -> dict[str, list[str]]:
         """
         memory = CentralMemory.get_memory_instance()
         values: dict[str, list[str]] = {}
-        for name in (
-            self.DATASET_EXAMPLE_DOMAINS,
-            self.DATASET_MARKDOWN_JS,
-            self.DATASET_WEB_HTML_JS,
-            self.DATASET_NORMAL_INSTRUCTIONS,
-        ):
+        for name in self._dataset_config.dataset_names:
             seeds = await memory.get_seeds_async(dataset_name=name)
             values[name] = [seed.value for seed in seeds]
         return values
@@ -532,13 +544,40 @@ def _build_synthesized_seed_groups(
                 seed_groups_by_technique[technique.value] = seed_groups
 
         if not seed_groups_by_technique:
-            raise ValueError(
-                "WebInjection scenario produced no prompts. Ensure the garak web-injection datasets "
-                "(garak_example_domains_xss, garak_markdown_js, garak_web_html_js, "
-                "garak_xss_normal_instructions) are loaded into CentralMemory before running."
-            )
+            selected = ", ".join(self._dataset_config.dataset_names) or "none"
+            raise ValueError(f"WebInjection scenario produced no prompts from the selected datasets ({selected}).")
         return seed_groups_by_technique
 
+    def _validate_runtime_configuration(self) -> None:
+        """
+        Check that the selected datasets cover every selected technique, without reading them.
+
+        Runs before both the preview estimate and initialization, so an incomplete
+        ``--dataset-names`` selection fails the same way whether or not memory already holds
+        the omitted dataset.
+
+        Raises:
+            DatasetConstraintError: If inline seeds are supplied, or a selected technique
+                needs a dataset that is not selected.
+        """
+        super()._validate_runtime_configuration()
+        if self._dataset_config.source_kind is DatasetSourceKind.INLINE:
+            raise DatasetConstraintError(
+                "WebInjection does not support inline seeds or seed groups; use dataset_names instead."
+            )
+        selected_datasets = set(self._dataset_config.dataset_names)
+        problems: list[str] = []
+        for selected in self._scenario_techniques:
+            technique = WebInjectionTechnique(selected.value)
+            problems.extend(
+                f"Technique '{technique.value}' requires dataset '{dataset_name}', "
+                "which is missing from the selected dataset names (--dataset-names)."
+                for dataset_name in self._TECHNIQUE_REQUIRED_DATASETS[technique]
+                if dataset_name not in selected_datasets
+            )
+        if problems:
+            raise DatasetConstraintError(" ".join(problems))
+
     def _get_technique_size_budgets(self) -> dict[WebInjectionTechnique, BoundedDatasetSize]:
         """Return the selected techniques' configured caps."""
         budgets: dict[WebInjectionTechnique, BoundedDatasetSize] = {}