[BUG] Inconsistent handling of reasoning tags (<think>, <thinking>, <reasoning>, <thought>)

[jwadow]

Problem (one or two sentences)

Roo Code processes reasoning tags inconsistently. The <think> tag renders correctly as a collapsible grey reasoning block, <thinking> has its tags stripped but text remains visible, and <reasoning>/<thought> are not recognized at all. This inconsistency breaks proper reasoning display.

Context (who is affected and when)

Affects users running models through different OpenAI-compatible endpoints, where the reasoning tag name may vary (<think>, <thinking>, <reasoning>, <thought>). Roo Code’s rigid handling reduces compatibility and flexibility with providers that output alternative reasoning tag formats.

This issue is related to a previously closed discussion: #7615

The collaborator incorrectly attributed the behavior to the "OpenAI reasoning chunk format" rather than tag handling in "content". I left a detailed follow-up comment explaining that Roo Code currently processes only <think> blocks, while <thinking>, <reasoning>, and <thought> are ignored or stripped. The issue has remained unresolved for over a month.
Expected resolution: unify tag handling so that all four tag variants render identically to in the grey collapsible reasoning block.

<think> works correctly

<thinking> tags removed, text visible

<reasoning> not formatted

<thought> not formatted

Reproduction steps

1. Use any provider that outputs reasoning wrapped in tags: <think>, <thinking>, <reasoning>, or <thought>.
2. Observe Roo Code's display of each case.
3. <think> renders correctly as a grey collapsible reasoning block.
4. <thinking> has its tags stripped and content shown as normal text.
5. <reasoning> and <thought> are not formatted or recognized at all.

Expected result

All four reasoning tag variants (, , , ) should be treated consistently and rendered as the same collapsible grey reasoning block.

Actual result

Only is formatted correctly. The other three tags are either stripped or ignored entirely.

Variations tried (optional)

Tested multiple models, providers, and output formats. Behavior consistent across all. No difference depending on provider.

App Version

3.28.18

API Provider (optional)

None

Model Used (optional)

No response

Roo Code Task Links (optional)

No response

Relevant logs or errors (optional)

[roomote]

I'm exploring a potential fix for the inconsistent reasoning tag handling. I'll work on unifying the behavior so that all four tag variants (<think>, <thinking>, <reasoning>, <thought>) render identically as collapsible grey reasoning blocks.

[roomote]

I've opened PR #8786 with my attempt at addressing this issue: #8786

The implementation ensures all four reasoning tag variants (<think>, <thinking>, <reasoning>, <thought>) are handled consistently and rendered as collapsible grey reasoning blocks.

The changes include:

• Updated tag stripping logic to handle all variants
• Created a ReasoningXmlMatcher utility for providers
• Updated all relevant provider parsers

Feedback welcome!