# Aider v0.83.0: drops Python 3.9, Gemini 2.5 Pro aliases move to 05-06 preview

> Aider dropped support for Python 3.9 — an environment-level break for anyone still on it. It also repointed the `gemini` and `gemini-2.5-pro` aliases at the 05-06 preview models, added qwen3-235b support, and enabled `thinking_tokens` / `reasoning_effort` for OpenRouter models.

| | |
|---|---|
| **Tool** | Aider |
| **Version** | v0.83.0 |
| **Kind** | release |
| **Published** | 2025-05-09 |
| **Observed** | 2026-08-11 |
| **Significance** | 3/5 |
| **Breaking** | yes |
| **Categories** | breaking, model-support, feature, fix |

## What changed


- **Python 3.9 support dropped.**
- Added `gemini-2.5-pro-preview-05-06` and `qwen3-235b` models.
- Gemini aliases (`gemini`, `gemini-2.5-pro`) repointed to the `05-06` previews; those previews marked `overeager` by default.
- Default weak model for Gemini 2.5 Pro is now `gemini/gemini-2.5-flash-preview-04-17`; `reasoning_effort` enabled for Gemini 2.5 Flash.
- Corrected `gemini-2.5-pro-exp-03-25` settings — it does not support `thinking_budget`.
- `thinking_tokens` and `reasoning_effort` now supported for OpenRouter models; model params (context window, pricing) fetched from OpenRouter directly; cost calculation uses `litellm.completion_cost` where available.
- New `--attribute-co-authored-by` adds a co-author trailer; explicit `--attribute-author` / `--attribute-committer` override it.
- New `--disable-playwright` flag; `aider scrape` and the GUI use Playwright when available and honour the flag.
- New `--shell-completions` argument to emit bash/zsh completion scripts.
- Repo-map support for OCaml and OCaml interface files; repo map shows token progress and the file being processed.
- Windows linter execution fixed via `oslex` argument quoting; same for cross-platform shell command display.
- `/ask` instructs the model to elide unchanged code.
- Fix: read-only file status not preserved by some commands (e.g. `/drop`).
- `aider-args` prints a sample YAML config when given no arguments.
- Total tokens sent/received now tracked in benchmark stats.
- Spinner added while waiting for the stream to start, extended to non-streaming responses.


## Sources

- [github_release](https://github.com/Aider-AI/aider/releases/tag/v0.83.0) — retrieved 2026-08-11

## Community

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Canonical: https://changelogs.info/aider/v0-83-0
Entity: https://changelogs.info/aider
Event ID: `evt_2025-05-09_aider_v0-83-0`
Licence: event synthesis © changelogs.info, CC BY 4.0. Linked sources belong to their vendors.