fix(ui): keep untouched stored auto-router booleans and reminder marker casing on save

[devin-ai-integration]

TLDR

Problem this solves:

• Saving an untouched auto-router drops route_housekeeping_to_cheapest_tier: true
• The same save drops max_tokens_from_tier_model: true
• reminder_markers come back lowercased without the user touching them

How it solves it:

• Save keeps the stored value for those keys when the form still equals what was hydrated from it
• An actual edit to any of them still wins and goes through the builder as before
• Regression test asserts the whole rebuilt config equals the stored one

User Flow

Before: an admin opens a router created before #42293, saves without changing anything, and two settings silently disappear

1. They open http://localhost:3000/models-and-endpoints/, click Auto-Routers, then click legacy-auto-router
2. On the Raw JSON tab they see "route_housekeeping_to_cheapest_tier": true, "max_tokens_from_tier_model": true and "open": "<System-Reminder>"
3. They click Overview, then Edit Auto Router, scroll to the bottom and click Save Changes without editing any field
4. The modal closes with a success toast
5. They open the Raw JSON tab again: both boolean keys are gone and the marker now reads "open": "<system-reminder>"
6. GET http://localhost:4000/model/info confirms the same: both keys are null and the markers are lowercased

After: the same untouched save leaves the stored settings exactly as they were

1. They open http://localhost:3000/models-and-endpoints/, click Auto-Routers, then click legacy-auto-router
2. On the Raw JSON tab they see "route_housekeeping_to_cheapest_tier": true, "max_tokens_from_tier_model": true and "open": "<System-Reminder>"
3. They click Overview, then Edit Auto Router, scroll to the bottom and click Save Changes without editing any field
4. The modal closes with a success toast
5. They open the Raw JSON tab again: both keys are still true and the marker still reads "open": "<System-Reminder>"
6. GET http://localhost:4000/model/info returns the same three values unchanged

Relevant issues

Follow-up to #42293, which added these three keys to the managed set

Affected release

Linear ticket

Pre-Submission checklist

Please complete all items before asking a LiteLLM maintainer to review your PR

• I have added meaningful tests
• The handful of test files covering my change pass locally: npx vitest run src/components/edit_auto_router src/components/add_model from ui/litellm-dashboard (44 files, 1159 tests)
• My PR passes all required CI/CD checks (e.g., lint, schema.d.ts sync check, etc.)
• My PR's scope is as isolated as possible; it only solves 1 specific problem
• I have received a Greptile Confidence Score of at least 4/5 before requesting a maintainer review (Greptile reviews automatically once the PR is opened; only comment @greptileai to re-request a review after pushing changes)

Screenshots / Proof of Fix

Shared setup: proxy on http://localhost:4000 with STORE_MODEL_IN_DB=True and Postgres, dashboard via npm run dev in ui/litellm-dashboard on http://localhost:3000, logged in as admin with the master key. The router was seeded through the API the way a pre-#42293 config would sit in the DB, then reseeded to the identical state before the After leg:

curl -s -X POST http://localhost:4000/model/new -H "Authorization: Bearer $LITELLM_MASTER_KEY" -H 'Content-Type: application/json' -d '{
  "model_name": "legacy-auto-router",
  "litellm_params": {
    "model": "auto_router/complexity_router",
    "complexity_router_default_model": "gpt-4o-mini",
    "complexity_router_config": {
      "tiers": {"SIMPLE": ["gpt-4o-mini"], "MEDIUM": ["gpt-4o-mini"], "COMPLEX": ["gpt-4o-mini"], "REASONING": ["gpt-4o-mini"]},
      "default_model": "gpt-4o-mini",
      "classifier_type": "heuristic_first",
      "heuristic_first_max_tier": "SIMPLE",
      "classifier_llm_config": {"model": "gpt-4o-mini", "timeout_ms": 3000},
      "route_housekeeping_to_cheapest_tier": true,
      "housekeeping_patterns": ["conversation title"],
      "reminder_markers": [{"open": "<System-Reminder>", "close": "</System-Reminder>"}],
      "max_tokens_from_tier_model": true
    }
  }
}'

Read-back used after each Save:

curl -s -H "Authorization: Bearer $LITELLM_MASTER_KEY" http://localhost:4000/model/info |
  jq '.data[] | select(.model_name=="legacy-auto-router") | .litellm_params.complexity_router_config
      | {route_housekeeping_to_cheapest_tier, max_tokens_from_tier_model, reminder_markers}'

Reviewer steps, identical on both legs: open http://localhost:3000/models-and-endpoints/, click Auto-Routers, click legacy-auto-router, click Edit Auto Router, scroll to the bottom of the modal, click Save Changes without touching any field, then click the Raw JSON tab and run the read-back curl

Before (40ec84c)

Untouched Save on a pre-#42293 router

1. Edit Auto Router modal, nothing edited, about to click Save Changes

2. Raw JSON after Save: route_housekeeping_to_cheapest_tier and max_tokens_from_tier_model are gone, marker is <system-reminder>

3. Read-back curl output

{
  "route_housekeeping_to_cheapest_tier": null,
  "max_tokens_from_tier_model": null,
  "reminder_markers": [
    {
      "open": "<system-reminder>",
      "close": "</system-reminder>"
    }
  ]
}

Regression tests

1. npx vitest run src/components/edit_auto_router/build_updated_complexity_router_config.test.ts with the new tests on unfixed code

 × returns the stored config unchanged when nothing was edited
 × keeps both housekeeping and max-token booleans stored as true
 × keeps the stored reminder marker casing
AssertionError: expected { tiers: { …(4) }, …(39) } to deeply equal { tiers: { …(4) }, …(41) }
-   "max_tokens_from_tier_model": true,
-       "close": "</System-Reminder>",
-       "open": "<System-Reminder>",
+       "close": "</system-reminder>",
+       "open": "<system-reminder>",
-   "route_housekeeping_to_cheapest_tier": true,
AssertionError: expected undefined to be true // Object.is equality
AssertionError: expected [ { open: '<system-reminder>', …(1) } ] to deeply equal [ { open: '<System-Reminder>', …(1) } ]
 Test Files  1 failed (1)
      Tests  3 failed | 96 passed (99)

After (3fbbf57)

Untouched Save on a pre-#42293 router

1. Edit Auto Router modal, nothing edited, about to click Save Changes

2. Raw JSON after Save: both keys still true, marker still <System-Reminder>

3. Read-back curl output

{
  "route_housekeeping_to_cheapest_tier": true,
  "max_tokens_from_tier_model": true,
  "reminder_markers": [
    {
      "open": "<System-Reminder>",
      "close": "</System-Reminder>"
    }
  ]
}

Regression tests

1. Same vitest command on the fixed code

 Test Files  1 passed (1)
      Tests  99 passed (99)

2. Mutation proof: reverting edit_auto_router_modal.tsx to the merge-base version while keeping the new tests

 Test Files  1 failed (1)
      Tests  3 failed | 96 passed (99)

3. Mutation proof: deleting only the if (unedited.has(key)) return false; guard

 Test Files  1 failed (1)
      Tests  4 failed | 95 passed (99)

4. Existing suites unedited: build_complexity_router_config.test.ts, hydrate_complexity_router_config.test.ts, edit_auto_router_modal.integration.test.tsx and the rest of build_updated_complexity_router_config.test.ts

 Test Files  4 passed (4)
      Tests  455 passed (455)

Pre-push gates: the base-vs-head A/B above is the live-pr-risk check for this change (the only dependent of buildUpdatedComplexityRouterConfig is the modal's Save and availability check, both exercised in the run), and an adversarial five-lens self-review of the diff ran inline with no finding at or above the blocker threshold

Type

🐛 Bug Fix

Caveats (if any)

Medium

• A stored value hydration rejects (say a string where a boolean belongs) is now preserved on untouched saves instead of being dropped
  • Before this change the managed set always rebuilt those keys, so invalid stored values were silently cleaned up on Save
  • Editing the field still replaces it

Low

• UNEDITED_STORED_VALUE_KEYS lists the three keys the builder emits only on false; a fourth such key would need adding here too
• Equality is by JSON.stringify, so a form value that differs only in object key order counts as edited and falls back to the old builder path
• npx tsc --noEmit in the dashboard reports the same pre-existing errors at the merge base and at this tip, none in the changed files

Final Attestation

• The tests check the right things, including the edge cases, and regressions in the respective real-world customer use-cases are not possible after this PR

Link to Devin session: https://app.devin.ai/sessions/c9c9660a39f94254a359d117f6644a08
Open in Devin Desktop: https://app.devin.ai/desktop/session/c9c9660a39f94254a359d117f6644a08?variant=devin

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge because untouched stored values are preserved without changing the established behavior for edited values

Summary

This PR preserves three stored auto-router settings when the corresponding hydrated form values remain untouched

• Keeps explicit stored boolean values from disappearing during an unchanged save
• Preserves the original casing of untouched reminder markers
• Continues routing edited values through the existing configuration builder
• Adds regression coverage for untouched round trips and explicit edits

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