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fix: add ping keepalive configuration for HTTP stream transport to prevent SSE timeouts #94

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@cswkim cswkim commented Nov 5, 2025

Description

When running the server in Docker with HTTP stream transport (used by LibreChat and similar clients), SSE connections time out after ~60 seconds of inactivity, causing:

  • Repeated disconnections
  • Reconnect loops
  • Unstable connections in production

Configure FastMCP's built-in ping/keepalive for HTTP stream transport. The server sends periodic keepalive messages every 30 seconds (configurable) to prevent timeouts.

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  • Adhere to semantic messaging and prefix your PR title with feat:, fix:, chore:, docs:, etc.
  • I’ve added tests if needed
  • I’ve updated documentation if applicable
  • I’ve tested this locally
  • Add a changeset (pnpm changeset) if necessary

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  • Run the tests with pnpm test.
  • Run the lint check with pnpm lint.
  • Run the code formatting (prettier) check with pnpm format.

Related Issues

Closes #93

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changeset-bot bot commented Nov 5, 2025

🦋 Changeset detected

Latest commit: e950f3c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package
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discogs-mcp-server Patch

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@cswkim cswkim mentioned this pull request Nov 6, 2025
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alonsocamaro commented Nov 7, 2025 •
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Thanks!

I´m seeing the following messages:

[INFO 2025-11-07T10:42:48.049Z] "Discogs MCP Server" started with transport type: stream
[FastMCP info] server is running on HTTP Stream at http://0.0.0.0:3002/mcp
[FastMCP info] HTTP Stream session established
[mcp-proxy] establishing new SSE stream for session ID 87db4756-939e-43cf-8f8d-83dae64db95f
[FastMCP info] HTTP Stream session established
[mcp-proxy] establishing new SSE stream for session ID c8557776-ba4e-400e-994c-e03bed2c14dc
[FastMCP info] HTTP Stream session established
[mcp-proxy] establishing new SSE stream for session ID 8cb08e7e-d133-4d79-bdcc-56fb6388722d
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed

the ping failed messages appear randomly, sometimes after 1 second. I´m using the defaults (no configuration).

In LibreChat I see the following

2025-11-07 10:43:48 info: [MCP][discogs] Streamable-http transport closed
2025-11-07 10:43:48 info: [MCP][discogs] -------------------------------------------------┐
2025-11-07 10:43:48 info: [MCP][discogs] URL: http://10.1.1.4:3002/mcp
2025-11-07 10:43:48 info: [MCP][discogs] OAuth Required: false
2025-11-07 10:43:48 info: [MCP][discogs] Capabilities: {"logging":{},"tools":{}}
2025-11-07 10:43:48 info: [MCP][discogs] Tools: get_release, get_release_rating_by_user, edit_release_rating, delete_release_rating, get_release_community_rating, get_master_release, get_master_release_versions, get_artist, get_artist_releases, get_label, get_label_releases, search, get_user_inventory, get_marketplace_listing, create_marketplace_listing, update_marketplace_listing, delete_marketplace_listing, get_marketplace_order, edit_marketplace_order, get_marketplace_orders, get_marketplace_order_messages, create_marketplace_order_message, get_marketplace_release_stats, inventory_export, get_inventory_exports, get_inventory_export, download_inventory_export, get_user_identity, get_user_profile, edit_user_profile, get_user_submissions, get_user_contributions, get_user_collection_folders, create_user_collection_folder, get_user_collection_folder, edit_user_collection_folder, delete_user_collection_folder, find_release_in_user_collection, get_user_collection_items, add_release_to_user_collection_folder, rate_release_in_user_collection, move_release_in_user_collection, delete_release_from_user_collection_folder, get_user_collection_custom_fields, edit_user_collection_custom_field_value, get_user_collection_value, get_user_wantlist, add_to_wantlist, edit_item_in_wantlist, delete_item_in_wantlist, get_user_lists, get_list, fetch_image
2025-11-07 10:43:48 info: [MCP][discogs] Server Instructions: undefined
2025-11-07 10:43:48 info: [MCP][discogs] Initialized in: 275ms
2025-11-07 10:43:48 info: [MCP][discogs] -------------------------------------------------┘
2025-11-07 10:43:48 error: [MCP][discogs] Transport error: SSE stream disconnected: AbortError: This operation was aborted
2025-11-07 10:43:48 info: [MCP][discogs] Reconnecting 1/3 (delay: 2000ms)
2025-11-07 10:43:48 error: [MCP][discogs] Transport error: SSE stream disconnected: AbortError: This operation was aborted
2025-11-07 10:43:48 info: MCP servers initialized successfully. Added 53 MCP tools.
2025-11-07 10:43:48 info: OAuth reconnect manager initialized successfully.
2025-11-07 10:43:50 info: [MCP][discogs] Creating streamable-http transport: http://10.1.1.4:3002/mcp
2025-11-07 10:43:51 info: [Login] [Login successful] [Username: u.alonsocamaro@f5.com] [Request-IP: 192.168.192.1]
2025-11-07 10:43:51 info: [MCP][discogs] Creating streamable-http transport: http://10.1.1.4:3002/mcp

Please note, in both the discogs mcp server and the amadeus mcp server I always see an initial ransport error: SSE stream disconnected: AbortError: This operation was aborted

I find that discogs logs should have timestamps, otherwise it´s hard/a guess to match the logs and the events or packet traces.

I´m attaching a PCAP file next

discogs-mcp-server-ping.github.pcap.txt

@alonsocamaro
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alonsocamaro commented Nov 7, 2025

btw, is there a way to increase verbosity of logs besides PING?

@cswkim
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cswkim commented Nov 10, 2025

Thanks!

I´m seeing the following messages:

[INFO 2025-11-07T10:42:48.049Z] "Discogs MCP Server" started with transport type: stream
[FastMCP info] server is running on HTTP Stream at http://0.0.0.0:3002/mcp
[FastMCP info] HTTP Stream session established
[mcp-proxy] establishing new SSE stream for session ID 87db4756-939e-43cf-8f8d-83dae64db95f
[FastMCP info] HTTP Stream session established
[mcp-proxy] establishing new SSE stream for session ID c8557776-ba4e-400e-994c-e03bed2c14dc
[FastMCP info] HTTP Stream session established
[mcp-proxy] establishing new SSE stream for session ID 8cb08e7e-d133-4d79-bdcc-56fb6388722d
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed
[FastMCP debug] server ping failed

the ping failed messages appear randomly, sometimes after 1 second. I´m using the defaults (no configuration).

In LibreChat I see the following

2025-11-07 10:43:48 info: [MCP][discogs] Streamable-http transport closed
2025-11-07 10:43:48 info: [MCP][discogs] -------------------------------------------------┐
2025-11-07 10:43:48 info: [MCP][discogs] URL: http://10.1.1.4:3002/mcp
2025-11-07 10:43:48 info: [MCP][discogs] OAuth Required: false
2025-11-07 10:43:48 info: [MCP][discogs] Capabilities: {"logging":{},"tools":{}}
2025-11-07 10:43:48 info: [MCP][discogs] Tools: get_release, get_release_rating_by_user, edit_release_rating, delete_release_rating, get_release_community_rating, get_master_release, get_master_release_versions, get_artist, get_artist_releases, get_label, get_label_releases, search, get_user_inventory, get_marketplace_listing, create_marketplace_listing, update_marketplace_listing, delete_marketplace_listing, get_marketplace_order, edit_marketplace_order, get_marketplace_orders, get_marketplace_order_messages, create_marketplace_order_message, get_marketplace_release_stats, inventory_export, get_inventory_exports, get_inventory_export, download_inventory_export, get_user_identity, get_user_profile, edit_user_profile, get_user_submissions, get_user_contributions, get_user_collection_folders, create_user_collection_folder, get_user_collection_folder, edit_user_collection_folder, delete_user_collection_folder, find_release_in_user_collection, get_user_collection_items, add_release_to_user_collection_folder, rate_release_in_user_collection, move_release_in_user_collection, delete_release_from_user_collection_folder, get_user_collection_custom_fields, edit_user_collection_custom_field_value, get_user_collection_value, get_user_wantlist, add_to_wantlist, edit_item_in_wantlist, delete_item_in_wantlist, get_user_lists, get_list, fetch_image
2025-11-07 10:43:48 info: [MCP][discogs] Server Instructions: undefined
2025-11-07 10:43:48 info: [MCP][discogs] Initialized in: 275ms
2025-11-07 10:43:48 info: [MCP][discogs] -------------------------------------------------┘
2025-11-07 10:43:48 error: [MCP][discogs] Transport error: SSE stream disconnected: AbortError: This operation was aborted
2025-11-07 10:43:48 info: [MCP][discogs] Reconnecting 1/3 (delay: 2000ms)
2025-11-07 10:43:48 error: [MCP][discogs] Transport error: SSE stream disconnected: AbortError: This operation was aborted
2025-11-07 10:43:48 info: MCP servers initialized successfully. Added 53 MCP tools.
2025-11-07 10:43:48 info: OAuth reconnect manager initialized successfully.
2025-11-07 10:43:50 info: [MCP][discogs] Creating streamable-http transport: http://10.1.1.4:3002/mcp
2025-11-07 10:43:51 info: [Login] [Login successful] [Username: u.alonsocamaro@f5.com] [Request-IP: 192.168.192.1]
2025-11-07 10:43:51 info: [MCP][discogs] Creating streamable-http transport: http://10.1.1.4:3002/mcp

Please note, in both the discogs mcp server and the amadeus mcp server I always see an initial ransport error: SSE stream disconnected: AbortError: This operation was aborted

I find that discogs logs should have timestamps, otherwise it´s hard/a guess to match the logs and the events or packet traces.

I´m attaching a PCAP file next

discogs-mcp-server-ping.github.pcap.txt

The ping failures look like a FastMCP issue - it may be pinging before sessions are ready. The initial disconnect happens with both servers, so that’s possibly a LibreChat initialization issue.

Our logs already have timestamps, but FastMCP’s don’t, which makes correlation harder.
Quick test: try setting PING_ENABLED=false to see if the connection stays stable without ping. If it does, we can disable it or wait for a FastMCP fix. The keepalive was meant to prevent timeouts, but if it’s causing failures, it may be counterproductive.

Can you try disabling ping and share the results?

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Using discogs + docker in stream mode reports SSE timeout errors with Librechat

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@cswkim @alonsocamaro