diff --git a/src/starbridge/web/__init__.py b/src/starbridge/web/__init__.py
index a947de5..5ddfdb5 100644
--- a/src/starbridge/web/__init__.py
+++ b/src/starbridge/web/__init__.py
@@ -2,6 +2,15 @@
 from .cli import cli
 from .service import Service
 from .settings import Settings
-from .types import GetResult, RobotForbiddenException
+from .types import Context, GetResult, LinkTarget, Resource, RobotForbiddenException
 
-__all__ = ["Service", "cli", "Settings", "RobotForbiddenException", "GetResult"]
+__all__ = [
+    "Service",
+    "cli",
+    "Settings",
+    "RobotForbiddenException",
+    "GetResult",
+    "Resource",
+    "Context",
+    "LinkTarget",
+]
diff --git a/src/starbridge/web/types.py b/src/starbridge/web/types.py
index af168fa..288b030 100644
--- a/src/starbridge/web/types.py
+++ b/src/starbridge/web/types.py
@@ -1,6 +1,6 @@
 from typing import Annotated
 
-from pydantic import BaseModel, Field
+from pydantic import AnyHttpUrl, AnyUrl, BaseModel, Field, model_validator
 
 
 class RobotForbiddenException(Exception):
@@ -25,8 +25,8 @@ class MimeType:
 
 
 class Resource(BaseModel):
-    url: Annotated[str, Field(description="Final URL of the resource")]
-    type: Annotated[str, Field(description="MIME type of the resource")]
+    url: Annotated[AnyHttpUrl, Field(description="Final URL of the resource")]
+    type: Annotated[str, Field(description="MIME type of the resource", min_length=4)]
     text: Annotated[
         str | None,
         Field(
@@ -40,24 +40,34 @@ class Resource(BaseModel):
         ),
     ] = None
 
+    @model_validator(mode="after")
+    def check_content_exists(self) -> "Resource":
+        if self.text is None and self.blob is None:
+            raise ValueError("Either text or blob must be provided")
+        if self.text is not None and self.blob is not None:
+            raise ValueError("Only one of text or blob must be provided")
+        return self
+
 
 class LinkTarget(BaseModel):
-    url: Annotated[str, Field(description="URL of the link target")]
+    url: Annotated[AnyUrl, Field(description="URL of the link target")]
     occurences: Annotated[
         int,
         Field(
-            description="Number of occurences of the url as a link target in the resource"
+            description="Number of occurences of the url as a link target in the resource",
+            ge=0,
         ),
     ]
+
     anchor_texts: Annotated[
         list[str],
-        Field(description="Anchor texts of the link target"),
+        Field(description="Anchor texts of the link target", min_length=1),
     ]
 
 
 class Context(BaseModel):
     type: Annotated[str, Field(description="Type of context")]
-    url: Annotated[str, Field(description="URL of the context")]
+    url: Annotated[AnyHttpUrl, Field(description="URL of the context")]
     text: Annotated[str, Field(description="Content of context in markdown format")]
 
 
diff --git a/tests/web/starbridge_web_types_test.py b/tests/web/starbridge_web_types_test.py
new file mode 100644
index 0000000..effa91a
--- /dev/null
+++ b/tests/web/starbridge_web_types_test.py
@@ -0,0 +1,15 @@
+import pytest
+from pydantic import ValidationError
+
+from starbridge.web import Resource
+
+
+def test_web_types_resource_exactly_one():
+    with pytest.raises(ValidationError):
+        Resource(
+            url="https://example.com", type="invalid", text="Hello World", blob=b"\0"
+        )
+    with pytest.raises(ValidationError):
+        Resource(url="https://example.com", type="invalid", text=None, blob=None)
+    Resource(url="https://example.com", type="invalid", text="Hello World", blob=None)
+    Resource(url="https://example.com", type="invalid", text=None, blob=b"\0")
diff --git a/tests/web/starbridge_web_utils_test.py b/tests/web/starbridge_web_utils_test.py
index ecfb1ed..a8aaddb 100644
--- a/tests/web/starbridge_web_utils_test.py
+++ b/tests/web/starbridge_web_utils_test.py
@@ -115,5 +115,5 @@ def mock_get_side_effect(url, **kwargs):
             (ctx for ctx in context if ctx.type == "llms_txt"), None
         )
         assert llms_txt_context is not None
-        assert llms_txt_context.url == "https://docs.anthropic.com/llms.txt"
+        assert str(llms_txt_context.url) == "https://docs.anthropic.com/llms.txt"
         assert llms_txt_context.text == LLMS_DUMY_CONTENT