fix(router): constrain same-name deployment routing by access groups by Sameerlite · Pull Request #26161 · BerriAI/litellm

Sameerlite · 2026-04-21T09:48:34Z

Summary

filter router candidate deployments by caller-authorized model access groups when access to a public model is granted via access-group membership
pass request_kwargs through get_available_deployment() so metadata-based filtering is applied on sync routing paths
add regression coverage for shared public model names across multiple access groups, plus a guard test for explicit model access behavior

Test plan

pytest tests/test_litellm/test_router.py -k \"access_group_scoped_key_filters_deployments_with_same_public_model or explicit_model_access_does_not_force_access_group_filtering\" -q

Note

Medium Risk
Changes core routing selection to enforce access-group-based authorization and alters fallback behavior, which could impact which deployments are chosen or when requests error. Risk is mitigated by added regression tests but affects permission-sensitive logic.

Overview
Router deployment resolution now applies access-group constraints when request metadata includes user_api_key_auth and the caller’s permissions for the requested public model are access-group-only, filtering candidate deployments (especially when multiple deployments share the same model_name).

It also prevents unauthorized bypass via routing fallbacks by (a) skipping the _get_deployment_by_litellm_model branch when access-group filtering emptied candidates and (b) blocking default fallbacks model substitution in the same scenario; sync get_available_deployment() now passes request_kwargs so this filtering runs on non-async paths.

Adds targeted tests covering access-group-scoped routing, explicit model access behavior, and regression cases ensuring neither litellm-model lookup nor default fallbacks can circumvent access-group restrictions.

^{Reviewed by Cursor Bugbot for commit 9d945fe. Bugbot is set up for automated code reviews on this repo. Configure here.}

Filter router candidate deployments by caller-authorized model access groups when access is granted via group membership, preventing cross-group load balancing for shared public model names. Made-with: Cursor

Add a router utils unit test that directly exercises _filter_deployments_by_model_access_groups for access-group-only key permissions. Made-with: Cursor

greptile-apps · 2026-04-21T09:57:17Z

Greptile Summary

This PR tightens Router deployment selection by filtering candidates to caller-authorized access groups when a key's access to a public model name is granted only via access-group membership. It extracts the pre-existing "model not in names" routing into _try_early_resolve_deployments_for_model_not_in_names, adds the new _filter_deployments_by_model_access_groups method, threads request_kwargs through the sync get_available_deployment path, and guards both the _get_deployment_by_litellm_model fallback and the default-fallback path against bypassing the filter when access-group filtering was the reason candidates were removed.

Confidence Score: 4/5

Safe to merge with care — the main guard paths are correctly implemented, but _try_early_resolve_deployments_for_model_not_in_names still returns team/pattern/default deployments without access-group filtering (pre-existing behavior, noted in prior review round).

No new P0/P1 issues found. Previously flagged P1s (stale _access_group_filter_emptied_candidates, _get_deployment_by_litellm_model bypass, default-fallback bypass) are all addressed by the guards in this PR. The remaining unguarded path in _try_early_resolve_deployments_for_model_not_in_names is pre-existing behavior flagged as P2 in a prior review round. Conservative 4/5 reflects the security-sensitive routing change.

litellm/router.py — specifically _try_early_resolve_deployments_for_model_not_in_names, which still returns team/pattern/default deployments without access-group filtering.

Important Files Changed

Filename	Overview
litellm/router.py	Adds `_filter_deployments_by_model_access_groups` and `_try_early_resolve_deployments_for_model_not_in_names`; threads `request_kwargs` through sync routing path; guards litellm-model and default-fallback paths against access-group bypass. Core logic is sound but `_try_early_resolve_deployments_for_model_not_in_names` still returns team/pattern/default deployments without access-group filtering.
tests/test_litellm/router_utils/test_router_utils_common_utils.py	Adds unit test for `_filter_deployments_by_model_access_groups` using a Router with access-group-tagged deployments; no real network calls.
tests/test_litellm/test_router.py	Adds five regression tests covering access-group scoping, explicit-model bypass, litellm-model-fallback guard, and default-fallback guard; all use `mock_response` and make no real network calls.

_{Reviews (8): Last reviewed commit: "Fix access-group bypass via litellm-mode..." | Re-trigger Greptile}

Document why empty allowed_access_groups intentionally preserves unfiltered deployments to avoid breaking non-access-group authorization paths. Made-with: Cursor

merge main

codecov · 2026-04-23T03:12:16Z

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

yuneng-berri · 2026-04-24T16:27:44Z

@Sameerlite Please see if the greptile comment is applicable here

Alluuu · 2026-04-27T07:11:02Z

@Sameerlite Thanks for paying attention to this issue, but is there anything I can do to help move this along?

mateo-berri · 2026-05-01T18:26:08Z

bugbot run

cursor

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit e942ef6. Configure here.}

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

mateo-berri · 2026-05-01T22:51:52Z

@greptileai

…ting-fix

mateo-berri · 2026-05-01T23:16:04Z

@greptileai

When _get_all_deployments returns 0 candidates and the litellm-model fallback branch (_get_deployment_by_litellm_model) finds deployments that the access-group filter then empties, _access_group_filter_emptied_candidates remained False (it was captured before that branch ran). The router would then proceed to default fallbacks; the fallback model could have no access_groups and short-circuit the filter, silently serving a caller blocked by access-group restrictions. Update the flag inside the litellm-model branch when filtering empties a non-empty candidate set so the default-fallback guard still triggers.

mateo-berri · 2026-05-01T23:47:03Z

@greptileai

mateo-berri · 2026-05-02T00:00:21Z

bugbot run

cursor

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 9d945fe. Configure here.}

mateo-berri

LGTM; thanks!

…ames The router_code_coverage CI check requires every function in router.py to be referenced by at least one test under tests/{local_testing, router_unit_tests,test_litellm} in a file with "router" in its name. The recently-extracted helper had no direct test, so the check failed with "0.45% of functions in router.py are not tested". Add a focused test that exercises the four return paths: model already in self.model_names, no fallback applies, pattern-router match, and default_deployment substitution (also asserting the stored default isn't mutated). https://claude.ai/code/session_019AVp1XL7RT9RxRe4qRLkay

CLAassistant · 2026-05-02T00:22:27Z

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

✅ mateo-berri
✅ Sameerlite
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…uting-fix fix(router): constrain same-name deployment routing by access groups

fix(router): constrain same-name deployment routing by access groups

437a179

Filter router candidate deployments by caller-authorized model access groups when access is granted via group membership, preventing cross-group load balancing for shared public model names. Made-with: Cursor

Sameerlite had a problem deploying to integration-postgres April 21, 2026 09:48 — with GitHub Actions Error

test(router): add coverage for access-group deployment filter

a3da472

Add a router utils unit test that directly exercises _filter_deployments_by_model_access_groups for access-group-only key permissions. Made-with: Cursor

Sameerlite temporarily deployed to integration-postgres April 21, 2026 09:52 — with GitHub Actions Inactive

Sameerlite had a problem deploying to integration-postgres April 21, 2026 09:52 — with GitHub Actions Error

Sameerlite temporarily deployed to integration-postgres April 21, 2026 09:52 — with GitHub Actions Inactive

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greptile-apps Bot reviewed Apr 21, 2026

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Comment thread litellm/router.py

chore(router): clarify empty access-group overlap behavior

d6be59e

Document why empty allowed_access_groups intentionally preserves unfiltered deployments to avoid breaking non-access-group authorization paths. Made-with: Cursor

Sameerlite temporarily deployed to integration-postgres April 21, 2026 09:59 — with GitHub Actions Inactive

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Sameerlite temporarily deployed to integration-postgres April 21, 2026 09:59 — with GitHub Actions Inactive

Merge pull request #26306 from BerriAI/litellm_internal_staging

ef1c6ae

merge main

Sameerlite temporarily deployed to integration-postgres April 23, 2026 03:09 — with GitHub Actions Inactive

Fix greptile review

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Sameerlite temporarily deployed to integration-postgres May 1, 2026 12:26 — with GitHub Actions Inactive

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Update litellm/router.py

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Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

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Comment thread litellm/router.py Outdated

Fix syntax errors from botched merge in router.py

36f03f1

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Merge branch 'litellm_internal_staging' into litellm_access-group-rou…

860f6b5

…ting-fix

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Comment thread litellm/router.py

Comment thread litellm/router.py

cursor Bot reviewed May 2, 2026

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mateo-berri approved these changes May 2, 2026

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Sameerlite merged commit d2015f0 into litellm_internal_staging May 2, 2026
115 checks passed

Sameerlite deleted the litellm_access-group-routing-fix branch May 2, 2026 05:49

fzowl pushed a commit to fzowl/litellm that referenced this pull request Jun 24, 2026

Merge pull request BerriAI#26161 from BerriAI/litellm_access-group-ro…

a65fbcd

…uting-fix fix(router): constrain same-name deployment routing by access groups

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Confidence Score: 4/5

Important Files Changed

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Sameerlite commented Apr 21, 2026 •

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