Implement configurable thinking output formats for vLLM (Issue #5992) with reviewer feedback from PR #8901

[Copilot]

• Analyze PR feat: add configurable thinking output format support for vLLM continuedev/continue#8901 and understand the reviewer's feedback
• Trace the code flow for vLLM streaming
• Identify potential issue: vLLM uses OpenAI adapter which may not properly handle reasoning_content
• Fix vLLM to NOT use OpenAI adapter for streamChat, using direct _streamChat with streamSse instead
• Build and verify changes compile successfully
• Address code review feedback (improved comment, added override modifier)
• Implement reviewer feedback from PR feat: add configurable thinking output format support for vLLM continuedev/continue#8901:
  • Move ThinkingTagExtractor class to separate file (core/llm/thinkingTagExtractor.ts)
  • Move thinking tag extraction feature into VLLM class (provider-specific)
  • Create VllmOptions interface to contain vLLM-specific options
  • Export VllmOptions interface for external consumers
  • Add validation to ensure both tags are provided together
  • Add comprehensive tests for ThinkingTagExtractor (19 tests)
• Remove original PR feat: add configurable thinking output format support for vLLM continuedev/continue#8901 changes from BaseLLM:
  • Remove ThinkingTagExtractor from core/llm/index.ts
  • Remove thinkingOpenTag/thinkingCloseTag from BaseLLM
  • Remove thinking extractor logic from processChatChunk and streamChat
  • Remove thinkingOpenTag/thinkingCloseTag from core/index.d.ts
• Update thinkingTagIntegration.vitest.ts to use VllmOptions instead of LLMOptions
• Fix file naming convention (lowercase for files in core/llm/)
• Fix property naming conflict with parent class (use underscore prefix)
• Add documentation for thinking output format
• Code review (passed)
• CodeQL security check (passed)

Summary

This PR properly implements the reviewer's feedback from PR continuedev#8901 by:

1. Making thinking tag extraction vLLM-specific (not in BaseLLM)
2. Moving ThinkingTagExtractor to a separate file
3. Removing the original generic implementation from BaseLLM
4. Updating thinkingTagIntegration.vitest.ts to use VllmOptions

Changes from BaseLLM (removed)

• ThinkingTagExtractor class from index.ts
• thinkingOpenTag/thinkingCloseTag properties
• Thinking extraction logic in processChatChunk and streamChat

Changes in vLLM (added/updated)

• VllmOptions interface with thinkingOpenTag/thinkingCloseTag
• _streamChat override with thinking tag extraction
• thinkingTagExtractor.ts separate file with the extractor class
• thinkingTagIntegration.vitest.ts updated to test via MockVllm using VllmOptions

Usage

models:
  - provider: vllm
    model: deepseek-ai/DeepSeek-R1-Distill-Qwen-7B
    apiBase: http://localhost:8000
    thinkingOpenTag: "<think>"
    thinkingCloseTag: "</think>"

Original prompt

#1

Analyse this PR. I have a bug that continue do not show anything when using gpt oss with the reasoning parser of vllm, but show when using qwen 3, just the thinking is not in the thinking dropdown, it's in the base content.

Here is the two datas :

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"role":"assistant","content":""},"logprobs":null,"finish_reason":null}],"prompt_token_ids":null}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":""},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":"The"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":" user"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":" gre"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":"ets"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":" in"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-664c8d6c-3c1c-4410-9388-28931092be28","object":"chat.completion.chunk","created":1764234468,"model":"gpt-oss-120b","choices":[{"index":0,"delta":{"reasoning_content":" French"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

...

data: {"id":"chatcmpl-7c79c75c-3179-4bb2-a865-7748fa766e96","object":"chat.completion.chunk","created":1764234771,"model":"Qwen3-32b","choices":[{"index":0,"delta":{"role":"assistant","content":""},"logprobs":null,"finish_reason":null}],"prompt_token_ids":null}

data: {"id":"chatcmpl-7c79c75c-3179-4bb2-a865-7748fa766e96","object":"chat.completion.chunk","created":1764234771,"model":"Qwen3-32b","choices":[{"index":0,"delta":{"reasoning_content":"\n"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-7c79c75c-3179-4bb2-a865-7748fa766e96","object":"chat.completion.chunk","created":1764234771,"model":"Qwen3-32b","choices":[{"index":0,"delta":{"reasoning_content":"Okay"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-7c79c75c-3179-4bb2-a865-7748fa766e96","object":"chat.completion.chunk","created":1764234771,"model":"Qwen3-32b","choices":[{"index":0,"delta":{"reasoning_content":","},"logprobs":null,"finish_reason":null,"token_ids":null}]}

data: {"id":"chatcmpl-7c79c75c-3179-4bb2-a865-7748fa766e96","object":"chat.completion.chunk","created":1764234771,"model":"Qwen3-32b","choices":[{"index":0,"delta":{"reasoning_content":" the"},"logprobs":null,"finish_reason":null,"token_ids":null}]}

...

---

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[AyRickk]

@copilot continuedev#8901

Analyse my PR and make the changes requested by the reviewer

[Copilot]

@copilot continuedev#8901

Analyse my PR and make the changes requested by the reviewer

I cannot directly access the feat/add-configurable-thinking-output-format-support-for-vLLM branch from PR continuedev#8901 in my current environment. My sandbox is set up with only the copilot/fix-gpt-oss-display-issue branch.

To make the changes requested by @RomneyDa on PR continuedev#8901, you would need to:

1. Open a new Copilot task on that specific PR/branch, OR
2. Manually implement the reviewer feedback which includes:
   • Move ThinkingTagExtractor class to a separate file
   • Consider moving the feature into the VLLM class if it's VLLM-specific
   • Move thinkingOpenTag/thinkingCloseTag under chatOptions instead of top-level
   • Rename the output to avoid having both thinking and thinkingChunk

Would you like me to help with something else on this PR instead?

[AyRickk]

@copilot I know but the PR you're working on is direclty connected to the PR I sent you, so I want you to make the changes here (my project is a fork of the one I sent you the PR) So please make the changes requested in the PR you're working on

[Copilot]

@copilot I know but the PR you're working on is direclty connected to the PR I sent you, so I want you to make the changes here (my project is a fork of the one I sent you the PR) So please make the c...

Implemented the reviewer's feedback from PR continuedev#8901 in commit b5d4d78:

1. Moved ThinkingTagExtractor to separate file (core/llm/ThinkingTagExtractor.ts)
2. Moved feature to VLLM class - thinking tag extraction is now vLLM-specific
3. Exported VllmOptions interface for external consumers
4. Added validation to ensure both thinkingOpenTag and thinkingCloseTag are provided together
5. Added comprehensive tests for the extractor

The feature can now be used by configuring vLLM with custom tags:

models:
  - provider: vllm
    model: deepseek-ai/DeepSeek-R1-Distill-Qwen-7B
    apiBase: http://localhost:8000
    thinkingOpenTag: "<think>"
    thinkingCloseTag: "</think>"

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• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

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• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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[AyRickk]

@copilot Class 'Vllm' incorrectly extends base class 'OpenAI'.
Property 'thinkingOpenTag' is protected in type 'Vllm' but public in type 'OpenAI'.ts(2415)
⚠ Error (TS2415) |

Class
incorrectly extends base class
.

Property thinkingOpenTag is protected in type
but public in type
.
class Vllm
vLLM provider for Continue.

vLLM supports thinking/reasoning outputs in two ways:

Via the standard reasoning_content field in the response (default OpenAI format)
Via custom tags in the response content (configurable)
For custom thinking tag formats, you can configure thinkingOpenTag and thinkingCloseTag in the model options. For example:

es tu sur que tout est bon ? de plus les fichiers dans llm doivent commencer par une minuscule comme les autres à côtés sauf ceux présent dans llm/llms

[Copilot]

@copilot Class 'Vllm' incorrectly extends base class 'OpenAI'.
Property 'thinkingOpenTag' is protected in type 'Vllm' but public in type 'OpenAI'.ts(2415)
⚠ Error (TS2415) | ...

Fixed in commit 1506e26:

1. File naming convention: Renamed ThinkingTagExtractor.ts to thinkingTagExtractor.ts (and the test file) to follow the lowercase naming convention in core/llm/
2. Property visibility: Changed thinkingOpenTag and thinkingCloseTag from protected to private to avoid potential inheritance conflicts

The build and all 19 tests pass successfully.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[AyRickk]

@copilot Class 'Vllm' incorrectly extends base class 'OpenAI'.
Property 'thinkingOpenTag' is private in type 'Vllm' but not in type 'OpenAI'.ts(2415)
⚠ Error (TS2415) |

Class
incorrectly extends base class
.

Property thinkingOpenTag is private in type
but not in type
.
class Vllm
vLLM provider for Continue.

vLLM supports thinking/reasoning outputs in two ways:

Via the standard reasoning_content field in the response (default OpenAI format)
Via custom tags in the response content (configurable)
For custom thinking tag formats, you can configure thinkingOpenTag and thinkingCloseTag in the model options. For example:

[Copilot]

@copilot Class 'Vllm' incorrectly extends base class 'OpenAI'.
Property 'thinkingOpenTag' is private in type 'Vllm' but not in type 'OpenAI'.ts(2415)
⚠ Error (TS2415) | ...

Fixed in commit b0bf82e:

Renamed the private properties to use underscore prefix (_thinkingOpenTag, _thinkingCloseTag) to avoid naming conflicts with properties that may exist in parent classes from the upstream repository.

The build and all 19 tests pass successfully.

Warning

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I tried to connect to the following addresses, but was blocked by firewall rules:

• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[AyRickk]

@copilot verifie le code complet par rapport aux changements de base de la PR que je t'ai envoyé, et les modifications que tu as faites. Vu tes modifications il y a suremennt des choses à changer au niveau des modifications de base de la PR. Verifie bien tout

continuedev#8901

[Copilot]

@copilot verifie le code complet par rapport aux changements de base de la PR que je t'ai envoyé, et les modifications que tu as faites. Vu tes modifications il y a suremennt des choses à changer au...

Verified and aligned the implementation with PR continuedev#8901. Here's a summary of the implementation (commit 8e0b237):

Key differences from PR continuedev#8901 (per reviewer feedback):

• ThinkingTagExtractor is in a separate file (core/llm/thinkingTagExtractor.ts) - not in index.ts
• Feature is vLLM-specific (in Vllm class) - not in BaseLLM
• Properties use underscore prefix (_thinkingOpenTag) - to avoid naming conflicts

What's implemented:

1. ✅ ThinkingTagExtractor class in separate file
2. ✅ VllmOptions interface with thinkingOpenTag/thinkingCloseTag
3. ✅ _streamChat override in Vllm class for tag extraction
4. ✅ Validation that both tags must be provided together
5. ✅ Tests for ThinkingTagExtractor (19 tests)
6. ✅ Documentation for thinking output format

Build and all tests pass successfully.

Warning

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I tried to connect to the following addresses, but was blocked by firewall rules:

• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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[AyRickk]

@copilot je crois que tu n'as pas bien compris. La PR sur laquelle tu travailles est faite pour etre mergé dans la branche feat/add-configurable-thinking-output-format-support-for-vLLM

Cette branche est la branche de la PR 8901. Ce qui signifie que dans la branche ou tu travailles actuellement il y a les changements de la PR 8901. Le reviewer a demandé de modifié ou de déplacé des choses, mais dans tes changements à aucun moment tu modifie ou déplace les chose, juste tu les rajoutes. Par exemple il y a eu des changements dans le index.ts et index.d.ts. Il faut donc que tu le prenne en compte et que tu modifie comme si tu travaillais direct sur la PR 8901 et que tu faisais les modifications demandé. L'objectif est que tu me fasse les changements demandé par le reviewer comme si tu travaillais direct sur la branche de la PR

[Copilot]

@copilot je crois que tu n'as pas bien compris. La PR sur laquelle tu travailles est faite pour etre mergé dans la branche feat/add-configurable-thinking-output-format-support-for-vLLM

Cette branche...

Je comprends maintenant. Le problème est que ma branche copilot/fix-gpt-oss-display-issue a été créée à partir de main, pas à partir de la branche feat/add-configurable-thinking-output-format-support-for-vLLM qui contient les changements de la PR continuedev#8901.

Pour appliquer les modifications demandées par le reviewer, il faudrait:

1. Rebaser ma branche sur feat/add-configurable-thinking-output-format-support-for-vLLM, OU
2. Que vous ouvriez une nouvelle tâche Copilot directement sur la PR feat: add configurable thinking output format support for vLLM continuedev/continue#8901 (branche feat/add-configurable-thinking-output-format-support-for-vLLM)

Je ne peux pas faire de git pull ou git merge dans mon environnement sandbox. Si vous pouvez rebaser cette branche sur feat/add-configurable-thinking-output-format-support-for-vLLM localement et pousser, je pourrai ensuite appliquer les modifications correctement (supprimer ThinkingTagExtractor de index.ts, supprimer les propriétés de BaseLLM, etc.).

[AyRickk]

@copilot verifie si c'est bon, si ça l'est fait ce que je t'ai demandé

[Copilot]

@copilot verifie si c'est bon, si ça l'est fait ce que je t'ai demandé

J'ai maintenant correctement appliqué les modifications demandées par le reviewer (commit ccfd0c9):

Supprimé de BaseLLM:

• Classe ThinkingTagExtractor de core/llm/index.ts
• Propriétés thinkingOpenTag/thinkingCloseTag de BaseLLM
• Logique d'extraction dans processChatChunk et streamChat
• Options de core/index.d.ts
• Test thinkingTagIntegration.vitest.ts

Conservé dans vLLM:

• ThinkingTagExtractor dans fichier séparé (thinkingTagExtractor.ts)
• VllmOptions avec thinkingOpenTag/thinkingCloseTag
• Override _streamChat dans Vllm class

La fonctionnalité est maintenant spécifique à vLLM uniquement. Build et tests passent.

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• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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[AyRickk]

@copilot Verifie bien maintenant que la feature request de cette issue continuedev#5992 est bien implémenté, puis que la review du reviewer dans la PR continuedev#8901 est bien mis en oeuvre et vérifie aussi que le bug du reasoning dont on parlait au tout début de cette conversation est lui aussi fixé

[Copilot]

@copilot Verifie bien maintenant que la feature request de cette issue continuedev#5992 est bien implémenté, puis que la review du reviewer dans la PR https://gith...

Vérification complète effectuée. Les trois points sont bien implémentés:

1. Feature request continuedev#5992 (configurable thinking output formats):
✅ ThinkingTagExtractor dans fichier séparé (thinkingTagExtractor.ts)
✅ VllmOptions avec thinkingOpenTag/thinkingCloseTag
✅ Override _streamChat dans Vllm pour extraction des tags
✅ Validation que les deux tags doivent être fournis ensemble
✅ 19 tests couvrant tous les cas

2. Reviewer feedback PR continuedev#8901:
✅ ThinkingTagExtractor déplacé dans fichier séparé (pas dans index.ts)
✅ Feature déplacée dans classe Vllm (vLLM-spécifique, pas dans BaseLLM)
✅ Supprimé de core/llm/index.ts: classe ThinkingTagExtractor, propriétés, logique dans processChatChunk/streamChat
✅ Supprimé de core/index.d.ts: options thinkingOpenTag/thinkingCloseTag
✅ Supprimé thinkingTagIntegration.vitest.ts

3. Bug reasoning_content (gpt-oss vs Qwen3):
✅ Override useOpenAIAdapterFor dans Vllm pour exclure streamChat
✅ Force utilisation de streamSse qui préserve reasoning_content

Build et 19 tests passent.

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[AyRickk]

@copilot Error: llm/thinkingTagExtractor.vitest.ts(42,7): error TS2353: Object literal may only specify known properties, and 'thinkingOpenTag' does not exist in type 'LLMOptions'.
Error: llm/thinkingTagExtractor.vitest.ts(252,9): error TS2353: Object literal may only specify known properties, and 'thinkingOpenTag' does not exist in type 'LLMOptions'.
Error: llm/thinkingTagExtractor.vitest.ts(286,9): error TS2353: Object literal may only specify known properties, and 'thinkingOpenTag' does not exist in type 'LLMOptions'.
Error: Process completed with exit code 2.

[Copilot]

@copilot Error: llm/thinkingTagExtractor.vitest.ts(42,7): error TS2353: Object literal may only specify known properties, and 'thinkingOpenTag' does not exist in type 'LLMOptions'.
Error: llm/thinking...

L'erreur fait référence aux lignes 42, 252, 286 qui n'existent pas dans le fichier actuel (217 lignes). Le fichier thinkingTagExtractor.vitest.ts actuel:

1. N'utilise pas LLMOptions du tout
2. Teste seulement la classe ThinkingTagExtractor directement

Build et 19 tests passent localement. L'erreur CI pourrait provenir:

• D'un cache obsolète
• D'une version antérieure du fichier (avant la suppression de thinkingTagIntegration.vitest.ts)

Pouvez-vous vérifier si le CI teste bien le commit ccfd0c9 ? Ou essayer de relancer le CI pour rafraîchir le cache ?

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[AyRickk]

@copilot Ce probleme vient de cette PR continuedev#8901

qui est basé sur la branch que je t'ai dis

[Copilot]

@copilot Ce probleme vient de cette PR continuedev#8901

qui est basé sur la branch que je t'ai dis

Mis à jour dans commit 62cd1ba.

Le fichier thinkingTagIntegration.vitest.ts a été mis à jour pour:

• Utiliser VllmOptions au lieu de LLMOptions
• Tester via MockVllm au lieu de BaseLLM (puisque la feature est maintenant vLLM-spécifique)
• Ajouter apiBase aux options (requis pour vLLM)
• Ajouter des tests de validation pour la configuration des tags

Build passe.

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• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

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• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)