# 400 Bad request

**URL:** <https://discuss.elastic.co/t/400-bad-request/381357>\
**Category:** Elasticsearch\
**Tags:** docker, vector-search\
**Created:** [August 27, 2025, 2:54am UTC](https://discuss.elastic.co/t/400-bad-request/381357 "2025-08-27T02:54:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![tarun-ghcp](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/tarun-ghcp/32/144783_2.png) [@tarun-ghcp](https://discuss.elastic.co/u/tarun-ghcp)\
**Post date:** [August 27, 2025, 2:54am UTC](https://discuss.elastic.co/t/400-bad-request/381357/1 "2025-08-27T02:54:49Z")

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I am using Docker container for MCP server. When running my Python script to do a knn search, the server throws 400 Bad request. But when request is sent without anything inside query\_body, it gives me the result. I couldn’t understand whats wrong within query\_body. Please help if you can.

payload script:

payload = {  
"jsonrpc": "2.0",  
"id": 11,  
"method": "tools/call",  
"params": {  
"name": "search",  
"arguments": {  
"index": "chunking\_test",  
"query\_body": {  
"size": 10,  
"query": {  
"bool": {  
"must\_not": [{"term": {"type.keyword": {"value": "Image"}}}]  
}  
},  
"knn": {  
"field": "embedding",  
"query\_vector": query\_vector,  
"k": k,  
"num\_candidates": k\*10  
}  
}  
}  
}  
}

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**Author:** ![Tortoise](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/tortoise/32/147587_2.png) [@Tortoise](https://discuss.elastic.co/u/Tortoise)\
**Post date:** [August 27, 2025, 3:31am UTC](https://discuss.elastic.co/t/400-bad-request/381357/2 "2025-08-27T03:31:14Z")

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This is duplicate to thread

> [@400-Bad request](https://discuss.elastic.co/t/400-bad-request/381344/2):
>
> Hello @tarun-ghcp Welcome to the Community!! Could you please check once below line : "must\_not": [{"term": {"type.keyword": {"value": "Image"}}}] I am not sure if we need to use value in the query as per the documentation "bool": { "must\_not": [{ "term": { "type.keyword": "Image" } }] } Thanks!!

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**Author:** ![stephenb](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephenb/32/40856_2.png) [@stephenb](https://discuss.elastic.co/u/stephenb)\
**Post date:** [August 27, 2025, 3:39am UTC](https://discuss.elastic.co/t/400-bad-request/381357/3 "2025-08-27T03:39:19Z")

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