Add capability to override default GitHub Copilot authentication endp…

[steromano87]

Relevant issues

Fixes #25914

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Type

🆕 New Feature

Changes

• Add support for configurable GitHub Copilot endpoints (via environment variables) to allow usage with GitHub Enterprise subscriptions with custom host (e.g. mycompany.ghe.com) or with self-hosted GitHub instances

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Project	Deployment	Actions	Updated (UTC)
litellm	Ready	Preview, Comment	Apr 16, 2026 11:23pm

[steromano87]

@greptileai

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[greptile-apps]

Greptile Summary

This PR adds support for configurable GitHub Copilot endpoints via environment variables (GITHUB_COPILOT_DEVICE_CODE_URL, GITHUB_COPILOT_ACCESS_TOKEN_URL, GITHUB_COPILOT_API_KEY_URL, GITHUB_COPILOT_CLIENT_ID, GITHUB_COPILOT_API_BASE), enabling use with GitHub Enterprise subscriptions and self-hosted GitHub instances. It also fixes the previously-inverted api_base priority in embedding/transformation.py and corrects the stale IndentationError in authenticator.py, making all three transformation paths consistent.

Confidence Score: 5/5

Safe to merge — all remaining findings are minor documentation polish with no impact on runtime behaviour.

The three previously-critical issues (IndentationError at import time, inverted api_base priority in embedding, os.getenv inside the polling loop) are all resolved. The new env-var fallback chains are consistent across all three transformation files, env-var lookups are correctly hoisted above retry loops in the authenticator, and the five new authenticator tests are mock-only and well-structured. The only remaining findings are P2 style issues in the provider documentation.

docs/my-website/docs/providers/github_copilot.md — unclosed parenthesis in comment and missing GITHUB_COPILOT_CLIENT_ID from the example block

Important Files Changed

Filename	Overview
litellm/llms/github_copilot/authenticator.py	Renames module-level constants to DEFAULT_* prefix and adds os.getenv() calls to support overriding URLs and client ID at call time; env var lookups are correctly hoisted above retry loops
litellm/llms/github_copilot/common_utils.py	Renames GITHUB_COPILOT_API_BASE constant to DEFAULT_GITHUB_COPILOT_API_BASE for consistency; no logic changes
litellm/llms/github_copilot/chat/transformation.py	Updates api_base fallback chain to: caller-supplied api_base → authenticator cache → GITHUB_COPILOT_API_BASE env var → hardcoded default; now consistent with embedding and responses paths
litellm/llms/github_copilot/embedding/transformation.py	Fixes previously-inverted api_base priority (was: authenticator → caller → default) to the correct order: caller → authenticator → env var → default; also adds env var layer
litellm/llms/github_copilot/responses/transformation.py	Adds GITHUB_COPILOT_API_BASE env var layer to the existing correct fallback chain; removes stale docstring that previously limited support to individual accounts only
tests/test_litellm/llms/github_copilot/test_github_copilot_authenticator.py	Adds 5 new mock-only tests covering all 4 new authenticator env vars (DEVICE_CODE_URL, ACCESS_TOKEN_URL, API_KEY_URL, CLIENT_ID); tests correctly use patch.dict and assert exact call arguments
docs/my-website/docs/providers/github_copilot.md	Documents 4 of the 5 new env vars; missing GITHUB_COPILOT_CLIENT_ID and has an unclosed parenthesis in the comment block
docs/my-website/docs/proxy/config_settings.md	Adds all 5 new env vars including GITHUB_COPILOT_CLIENT_ID with correct default value matching the code

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[Request to github_copilot provider] --> B{api_base supplied?}
    B -- Yes --> E[Use supplied api_base]
    B -- No --> C{authenticator.get_api_base from api-key.json?}
    C -- Yes --> E
    C -- No --> D{GITHUB_COPILOT_API_BASE env var set?}
    D -- Yes --> E
    D -- No --> F[Use DEFAULT_GITHUB_COPILOT_API_BASE]
    E --> G[Append /chat, /embeddings, or /responses]

    H[Device code auth flow] --> I{GITHUB_COPILOT_DEVICE_CODE_URL set?}
    I -- Yes --> J[POST to custom URL]
    I -- No --> K[POST to github.com/login/device/code]

    L[Poll for access token] --> M{GITHUB_COPILOT_ACCESS_TOKEN_URL set?}
    M -- Yes --> N[POST to custom URL]
    M -- No --> O[POST to github.com/login/oauth/access_token]

    P[Refresh API key] --> Q{GITHUB_COPILOT_API_KEY_URL set?}
    Q -- Yes --> R[GET from custom URL]
    Q -- No --> S[GET from api.github.com/copilot_internal/v2/token]

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_{Reviews (8): Last reviewed commit: "Fix default value for Copilot client ID ..." | Re-trigger Greptile}