error: Index build failed

[zierf]

What happened?

The update to v0.8.8-rc1 broke index builds.
I updated the repository from v0.8.7.

Changed the override for the docker image:

From: registry.librechat.ai/danny-avila/librechat:v0.8.7
To: registry.librechat.ai/danny-avila/librechat:v0.8.8-rc1

The new version is unable to build it's indexes and collides with existing ones.

Version Information

LibreChat version: v0.8.8-rc1
Commit: eaef87fa2684025627e25d649a56f4f2a63417a7
Branch: v0.8.8-rc1
Build date: 2026-08-14 07:33:24 UTC
User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36 Edg/151.0.0.0

Steps to Reproduce

1. docker compose down
2. Update Git-Repository and change Docker image from v0.8.7 to v0.8.8-rc1
3. docker compose up -d
4. docker compose logs -f api

What browsers are you seeing the problem on?

Firefox, Microsoft Edge

Relevant log output

{"level":"error","message":"Index build failed for \"Role\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { name: 1 }, name: \"name_1\", background: true }, existing index: { v: 2, unique: true, key: { name: 1 }, name: \"name_1\", background: true }","timestamp":"2026-08-14T12:38:50.082Z"}
{"level":"error","message":"Index build failed for \"Preset\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { presetId: 1 }, name: \"presetId_1\", background: true }, existing index: { v: 2, unique: true, key: { presetId: 1 }, name: \"presetId_1\", background: true }","timestamp":"2026-08-14T12:38:50.085Z"}
{"level":"error","message":"Index build failed for \"AccessRole\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { accessRoleId: 1 }, name: \"accessRoleId_1\", background: true }, existing index: { v: 2, unique: true, key: { accessRoleId: 1 }, name: \"accessRoleId_1\", background: true }","timestamp":"2026-08-14T12:38:50.088Z"}
{"level":"error","message":"Index build failed for \"MCPServer\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { serverName: 1 }, name: \"serverName_1\", background: true }, existing index: { v: 2, unique: true, key: { serverName: 1 }, name: \"serverName_1\", background: true }","timestamp":"2026-08-14T12:38:50.118Z"}
{"level":"error","message":"Index build failed for \"Message\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { messageId: 1 }, name: \"messageId_1\", background: true }, existing index: { v: 2, unique: true, key: { messageId: 1 }, name: \"messageId_1\", background: true }","timestamp":"2026-08-14T12:38:50.121Z"}
{"level":"error","message":"Index build failed for \"AgentCategory\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { value: 1 }, name: \"value_1\", background: true }, existing index: { v: 2, unique: true, key: { value: 1 }, name: \"value_1\", background: true }","timestamp":"2026-08-14T12:38:50.122Z"}
{"level":"error","message":"Index build failed for \"Conversation\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { conversationId: 1 }, name: \"conversationId_1\", background: true }, existing index: { v: 2, unique: true, key: { conversationId: 1 }, name: \"conversationId_1\", background: true }","timestamp":"2026-08-14T12:38:50.130Z"}
{"level":"error","message":"Index build failed for \"User\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { email: 1 }, name: \"email_1\", background: true }, existing index: { v: 2, unique: true, key: { email: 1 }, name: \"email_1\", background: true }","timestamp":"2026-08-14T12:38:50.134Z"}

Screenshots

Code of Conduct

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[danny-avila]

Thanks for the detailed report. Good news: nothing is broken, and this isn't a regression in rc1.

The index definitions are byte-identical between v0.8.7 and v0.8.8-rc1, with zero index changes in the diff. What's new is the logging. #14495 added a Mongoose index listener so background index-build failures stop being swallowed silently. Your database has been hitting this since you upgraded to 0.8.7, you just couldn't see it.

The conflict itself is harmless. Multi-tenancy replaced the single-field unique indexes with tenant-scoped compounds, so Mongoose now requests a non-unique name_1 while your DB still has the old unique one. Mongo rejects that single index and Mongoose continues building the rest. I verified against a 0.8.7-shaped database: every compound index gets created, and uniqueness is still enforced by the legacy indexes.

You can confirm on your instance:

db.conversations.getIndexes().map(i => i.name)

conversationId_1_user_1_tenantId_1 should be there alongside conversationId_1.

No action needed on your side. We'll drop the redundant single-field declarations to clear the noise.

[zierf]

Thank you very much!

Here is the predicted index list as reference for anyone interested:

[pedrojreis]

@danny-avila I think 8.8-rc4 got us a regression on the same manner

{"level":"error","message":"Index build failed for \"Assistant\": An existing index has the same name as the requested index. When index names are not specified, they are auto generated and can cause conflicts. Please refer to our documentation. Requested index: { v: 2, key: { assistant_id: 1 }, name: \"assistant_id_1\", background: true }, existing index: { v: 2, unique: true, key: { assistant_id: 1 }, name: \"assistant_id_1\", background: true }","timestamp":"2026-09-23T16:01:09.877Z"}