diff --git a/__tests__/create.testcases.md b/__tests__/create.testcases.md
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+# /create Endpoint Test Cases
+
+## Expected Behaviors
+
+### 1. POST /create with valid object
+- Should return 201
+- Response: created object
+
+### 2. POST /create with missing required fields
+- Should return 400
+- Response: error message indicating missing fields
+
+### 3. POST /create with malformed JSON
+- Should return 400 or 500
+- Response: error message, no stack trace
+
+### 4. POST /create with empty body
+- Should return 400
+- Response: error message
+
+### 5. POST /create with duplicate object
+- Should return 409
+- Response: error message indicating conflict
+
+---
+
+Add new cases as needed. Checklist for /create route.
diff --git a/__tests__/delete.testcases.md b/__tests__/delete.testcases.md
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+++ b/__tests__/delete.testcases.md
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+# /delete Endpoint Test Cases
+
+## Expected Behaviors
+
+### 1. DELETE /delete with valid object ID (body)
+- Should return 204
+- Response: no content
+
+### 2. DELETE /delete/:id with valid object ID (param)
+- Should return 204
+- Response: no content
+
+### 3. DELETE /delete with missing object ID
+- Should return 400
+- Response: error message indicating missing ID
+
+### 4. DELETE /delete with malformed JSON
+- Should return 400 or 500
+- Response: error message, no stack trace
+
+### 5. DELETE /delete with empty body
+- Should return 400
+- Response: error message
+
+### 6. DELETE /delete/:id with non-existent object
+- Should return 404
+- Response: error message indicating not found
+
+---
+
+Add new cases as needed. Checklist for /delete route.
diff --git a/__tests__/overwrite.testcases.md b/__tests__/overwrite.testcases.md
new file mode 100644
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+++ b/__tests__/overwrite.testcases.md
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+# /overwrite Endpoint Test Cases
+
+## Expected Behaviors
+
+### 1. PUT /overwrite with valid object and version
+- Should return 200
+- Response: overwritten object
+
+### 2. PUT /overwrite with missing version
+- Should return 400
+- Response: error message indicating missing version
+
+### 3. PUT /overwrite with version mismatch
+- Should return 409
+- Response: error message indicating conflict
+
+### 4. PUT /overwrite with malformed JSON
+- Should return 400 or 500
+- Response: error message, no stack trace
+
+### 5. PUT /overwrite with empty body
+- Should return 400
+- Response: error message
+
+---
+
+Add new cases as needed. Checklist for /overwrite route.
diff --git a/__tests__/query.testcases.md b/__tests__/query.testcases.md
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+++ b/__tests__/query.testcases.md
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+# Query Route Test Cases
+
+This file documents the test cases for the /query endpoint. These are not executable tests, but serve as a checklist for future test harness development.
+
+## Expected Behaviors
+
+### 1. POST /query with body {}
+- Should return 200
+- Response: empty result set (e.g., [])
+
+### 2. POST /query with body []
+- Should return 400
+- Response: error message indicating invalid query shape
+
+### 3. POST /query with body null
+- Should return 400
+- Response: error message indicating invalid query
+
+### 4. POST /query with body ""
+- Should return 400
+- Response: error message indicating invalid query
+
+### 5. POST /query with body 0
+- Should return 400
+- Response: error message indicating invalid query
+
+### 6. POST /query with body true
+- Should return 400
+- Response: error message indicating invalid query
+
+### 7. POST /query with valid query object
+- Should return 200
+- Response: result set matching query
+
+### 8. POST /query with malformed JSON (e.g., {broken json)
+- Should return 400 or 500
+- Response: error message, no stack trace
+
+### 9. POST /query with missing limit/skip
+- Should default to limit=10, skip=0
+- Should return 200
+
+### 10. POST /query with negative limit/skip
+- Should return 400
+- Response: error message indicating invalid parameters
+
+---
+
+Add new cases as needed. This file is for planning and tracking test coverage for /query route.
diff --git a/__tests__/update.testcases.md b/__tests__/update.testcases.md
new file mode 100644
index 0000000..f75e243
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+++ b/__tests__/update.testcases.md
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+# /update Endpoint Test Cases
+
+## Expected Behaviors
+
+### 1. PUT /update with valid object
+- Should return 200
+- Response: updated object
+
+### 2. PUT /update with missing object ID
+- Should return 400
+- Response: error message indicating missing ID
+
+### 3. PUT /update with malformed JSON
+- Should return 400 or 500
+- Response: error message, no stack trace
+
+### 4. PUT /update with empty body
+- Should return 400
+- Response: error message
+
+### 5. PUT /update with non-existent object
+- Should return 404
+- Response: error message indicating not found
+
+---
+
+Add new cases as needed. Checklist for /update route.