Error with Amazon Nova models when using tools via agent

[dvejsada]

What happened?

I have several agents with tools, so far using Antropic models over AWS Bedrock, everything works fine. We wanted to try using some of the amazon models, however they always throw an error (operation aborted) when it comes to potential tool use. There is no usefull information in any of the logs.

If I remove all the tools, the agent with Nova models work fine. It is thus clear there must be some bug with tool handling for these models in LibreChat.

Just as a side note, the model outputs thinking block (within tags) that does not hide in "thinking" bubble.

Version Information

ghcr.io/danny-avila/librechat-dev latest 91f197bb4191 10 days ago 1.03GB

Steps to Reproduce

1. Create Agent
2. Give some tools
3. USe Amazon Nova Pro/Premier model
4. See error

What browsers are you seeing the problem on?

No response

Relevant log output

{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Operation aborted aborted","pregelTaskId":"cf56af93-a74e-5d5c-a0fc-69c2435b01a1","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Unhandled error type aborted","pregelTaskId":"cf56af93-a74e-5d5c-a0fc-69c2435b01a1","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Operation aborted aborted","pregelTaskId":"f715068b-670f-5772-b0f7-92190628cee6","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Unhandled error type aborted","pregelTaskId":"f715068b-670f-5772-b0f7-92190628cee6","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Operation aborted aborted","pregelTaskId":"7de6b155-a4a9-526f-9883-5f07107f89d1","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Unhandled error type aborted","pregelTaskId":"7de6b155-a4a9-526f-9883-5f07107f89d1","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Operation aborted aborted","pregelTaskId":"22f9cd3d-bd3b-5b2a-9f7f-875304b40bd6","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Unhandled error type aborted","pregelTaskId":"22f9cd3d-bd3b-5b2a-9f7f-875304b40bd6","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Operation aborted aborted","pregelTaskId":"6aecd381-62d0-5818-a094-050651b77470","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}
{"code":"ECONNRESET","level":"error","message":"[api/server/controllers/agents/client.js #sendCompletion] Unhandled error type aborted","pregelTaskId":"6aecd381-62d0-5818-a094-050651b77470","stack":"Error: aborted\n    at TLSSocket.socketCloseListener (node:_http_client:464:19)\n    at TLSSocket.emit (node:events:536:35)\n    at node:net:343:12\n    at TCP.done (node:_tls_wrap:648:7)\n    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)"}

Screenshots

Code of Conduct

• I agree to follow this project's Code of Conduct

[danny-avila]

Try the latest build, AWS dependency was updated recently. See here, using nova-pro:

[dvejsada]

Thanks @danny-avila , I upgraded to: ghcr.io/danny-avila/librechat-dev latest 7ee5765fe941 15 hours ago 1.04GB, but the issue still persist. I tried whole line from micro to the newest premier, not one works. If I remove all the tools , it works fine. If I add even 1 tool and it tries to use it, it throws an error. If I switch to Anthropic models on Bedrock within same agent, it also works fine.

I have pinpointed that the issue is mainly with MCP-based tools. If I only connect plugin such as Dalle, or FileSearch, it works. But with mcp-tools it fails. The mcp-tools are working fine for other non- Amazon models.

Could you please investigate a bit more? It unfortunately makes whole line of quite good models (especially from price point of view) totally unusable.

[danny-avila]

Thank you for the detailed bug report and the additional clarification about MCP-based tools. I've investigated this issue extensively and can provide some important findings.
After deep debugging, this is not a LibreChat bug but rather an AWS Bedrock service-side issue specifically affecting Amazon Nova models during streaming operations. Here's what I discovered:

Technical Findings:

• The ECONNRESET error originates from AWS Bedrock's servers, not the client
• The connection is being terminated by the AWS service during streaming responses
• This occurs specifically when Nova models process more complex requests (like MCP tool interactions, which may have more complex tool schemas)
• The error happens at the TLS socket level: TLSSocket.socketCloseListener
• Also observed that the Nova models may sometimes fail to provide a proper tool call, and instead provides text, which may be part of the issue:
  

Evidence:

# AWS Bedrock endpoint where connection resets occur:
https://bedrock-runtime.us-east-1.amazonaws.com/model/us.amazon.nova-pro-v1%3A0/converse-stream

# Error signature confirms server-side termination:
Error: aborted at TLSSocket.socketCloseListener (node:_http_client:464:19)

Resolution Path

This appears to be a known issue with Amazon Nova model streaming infrastructure that should be escalated to AWS Support. Here's what I recommend:

This is a confirmed AWS Bedrock Nova streaming service issue, not a LibreChat implementation problem. The fact that it works with Anthropic models and fails consistently with all Nova models (micro to premier) confirms this is infrastructure-related.

I will personally follow up with some AWS contacts I have, since they especially want to ensure Nova is a competitive model and this type of reliability issue undermines that goal.

Thank you for the excellent debugging information - the MCP vs. regular plugin distinction was the key insight that confirmed the service-side nature of this issue.

[danny-avila]

Potentially related issue with Python SDK:

langchain-ai/langchain-aws#435

It unfortunately makes whole line of quite good models (especially from price point of view) totally unusable.

I agree, sadly this seems widespread for Nova.