diff --git a/src/routes/observations.js b/src/routes/observations.js
index 7281bdf..cc45cf6 100644
--- a/src/routes/observations.js
+++ b/src/routes/observations.js
@@ -78,6 +78,10 @@ export default async function observationRoutes(
       params: Type.Object({
         projectPublicId: Type.String(),
       }),
+      querystring: Type.Object({
+        versionId: Type.Optional(Type.String()),
+        category: Type.Optional(Type.String()),
+      }),
       body: schemas.observationToAdd,
       response: {
         201: Type.Literal(''),
@@ -90,9 +94,19 @@ export default async function observationRoutes(
     },
     handler: async (req) => {
       const { projectPublicId } = /** @type {ProjectRequest} */ (req).params
+      const { versionId, category } =
+        /** @type {import('fastify').FastifyRequest<{Querystring: {versionId?: string, category?: string}}>} */ (
+          req
+        ).query
       const body = /** @type {ObservationToAdd} */ (req.body)
       const project = await fastify.comapeo.getProject(projectPublicId)
 
+      let preset
+      if (category) {
+        const presets = await project.preset.getMany()
+        preset = presets.find((p) => p.name === category)
+      }
+      console.log('category', category, preset)
       const observationData = {
         schemaName: /** @type {const} */ ('observation'),
         lat: body.lat,
@@ -101,6 +115,9 @@ export default async function observationRoutes(
           ...attachment,
           hash: '', // Required by schema but not used
         })),
+        presetRef: preset
+          ? { docId: preset.docId, versionId: preset.versionId }
+          : null,
         tags: body.tags || {},
         metadata: body.metadata || {
           manualLocation: false,
@@ -115,7 +132,12 @@ export default async function observationRoutes(
         },
       }
 
-      const response = await project.observation.create(observationData)
+      let response
+      if (versionId) {
+        response = await project.observation.update(versionId, observationData)
+      } else {
+        response = await project.observation.create(observationData)
+      }
       return response
     },
   })
diff --git a/test/test_script.sh b/test/test_script.sh
index c7c3df3..026d19c 100755
--- a/test/test_script.sh
+++ b/test/test_script.sh
@@ -141,8 +141,8 @@ PROJECT_ID=${FIRST_PROJECT_ID}
 echo "Using project ID: ${PROJECT_ID}"
 echo
 
-# Test PUT /projects/:projectId/observation
-echo "PUT /projects/${PROJECT_ID}/observation"
+# Test PUT /projects/:projectId/observation - create
+echo "PUT /projects/${PROJECT_ID}/observation - create"
 echo "-------------------------------------"
 RESPONSE=$(curl -s -f -X PUT \
     -H "Authorization: Bearer ${BEARER_TOKEN}" \
@@ -158,6 +158,31 @@ echo "Response: ${RESPONSE}"
 echo "✅ Passed"
 echo
 
+# Get versionId from response
+# Parse response JSON to extract versionId
+VERSION_ID=$(echo "${RESPONSE}" | jq -r '.versionId')
+echo "Using version ID: ${VERSION_ID}"
+
+# Test PUT /projects/:projectId/observation - update
+echo "PUT /projects/${PROJECT_ID}/observation - update"
+echo "-------------------------------------"
+RESPONSE=$(curl -s -f -X PUT \
+    -H "Authorization: Bearer ${BEARER_TOKEN}" \
+    -H "Content-Type: application/json" \
+    -d '{
+        "lat": 0,
+        "lon": 0,
+        "tags": {
+            "notes": "Updated observation",
+            "category": "test"
+        },
+        "attachments": []
+    }' \
+    "${HOST}/projects/${PROJECT_ID}/observation?versionId=${VERSION_ID}") || (echo "❌ Failed" && exit 1)
+echo "Response: ${RESPONSE}"
+echo "✅ Passed"
+echo
+
 # Test GET /projects/:projectId/observations
 echo "GET /projects/${PROJECT_ID}/observations"
 echo "--------------------------------------"