# Aider: features, protocols, quickstart ## TL;DR Aider is an Apache-2.0 terminal tool for pair programming with LLMs, maintained in the Aider-AI/aider repository. It maps your repository, edits files through structured edit formats, commits each change to git, and works with most cloud and local models. It suits developers who want a single, git-centred coding assistant rather than multiple agents. ## Key facts | Field | Value | | --- | --- | | Type | Harness | | Languages / SDKs | Python | | License | Apache-2.0 | | Pricing model | Open source, free | | Orchestration pattern | Other | | GitHub stars | 49,292 (as of 2026-09-30) | | GitHub forks | 5,019 | | Last push | 2026-05-22 | | Latest release | v0.86.0 | | Repository | [Aider-AI/aider](https://github.com/Aider-AI/aider) | | Website | [aider.chat](https://aider.chat/) | | Documentation | [aider.chat](https://aider.chat/docs/install.html) | | Last verified | 2026-09-30 | ## Key features - Architect mode sends a request to an architect model for a proposed solution, then to an editor model that turns it into file edits; --editor-model picks the second model. ([source](https://aider.chat/docs/usage/modes.html)) - Chat modes code, ask, architect and help, switchable per message (/ask, /code, /architect) or with /chat-mode. ([source](https://aider.chat/docs/usage/modes.html)) - A repository map summarises the whole codebase so the model can work in larger projects. ([source](https://aider.chat/docs/repomap.html)) - Every change is committed to git with a generated message, and /undo reverts aider's last commit. ([source](https://aider.chat/docs/git.html)) - Connects to most cloud LLMs and to local models. ([source](https://aider.chat/docs/llms.html)) - Runs linters and tests after edits and can fix the problems they report. ([source](https://aider.chat/docs/usage/lint-test.html)) - Watch mode picks up instructions written as comments in your editor. ([source](https://aider.chat/docs/usage/watch.html)) - Scriptable from the shell with --message and from Python via Coder.create (the Python API is not officially supported). ([source](https://aider.chat/docs/scripting.html)) ## Architecture and orchestration pattern Pattern: Other. Aider runs one conversational coding loop in the terminal. You add files to the chat, aider builds a repository map to give the model a compact view of the rest of the codebase, and the model's reply is applied through an edit format (for example search/replace diffs or whole-file rewrites). Each applied change becomes a git commit, which serves as aider's history and undo mechanism. The docs describe no multi-agent mode: there are no subagents, teams or parallel sessions. The closest feature is architect mode, a fixed two-step sequence in which an architect model proposes a solution and an editor model converts it into file edits; the same model can fill both roles. For that reason the orchestration pattern is recorded as `other` rather than a multi-agent pattern. State is the git repository plus the current chat (files in chat, message history). There is no documented long-term memory beyond what is in the repository. ### Human in the loop Aider is interactive by default: the user adds and drops files, chooses the chat mode, and answers aider's confirmation prompts; `--yes-always` answers yes to every confirmation, and `--suggest-shell-commands` controls whether aider proposes shell commands at all. Ask mode discusses changes without editing, which the docs recommend before switching to code mode. Every edit is a git commit, `/diff` shows changes since the last message and `/undo` reverts aider's last commit. In architect mode, `--auto-accept-architect` (on by default) decides whether the architect's proposal is applied without asking. ## Protocols | Protocol | Support | Evidence | Note | | --- | --- | --- | --- | | MCP | Unknown (checked 2026-09-30) | — | Not in the README or docs; issue #3314 requesting MCP support is open, and PR #3672 adding it was closed without merging. Neither is a maintainer statement, so the cell stays unknown. | | A2A | Unknown (checked 2026-09-30) | — | No A2A mention in the README, the docs sources in aider/website/docs or the issue tracker search. | | AG-UI | Unknown (checked 2026-09-30) | — | No AG-UI mention in the README or docs, and aider is not in the AG-UI README integration list. | ## Best for - Git-centred pair programming in the terminal where every AI change is a reviewable commit. ([shortlist](https://multiagentguide.top/best/coding-agents.md)) - Running coding help against local models as well as cloud APIs. ([shortlist](https://multiagentguide.top/best/self-hosted-local.md)) - Pairing a strong reasoning model with a separate editing model through architect mode. ## Not for - Multi-agent workflows: aider documents no subagents, teams or parallel sessions. - Projects that need MCP tools; MCP support is only an open feature request. - Teams that need an actively released tool: the latest release is v0.86.0 from 2025-08-09. ## Quickstart ```sh python -m pip install -U --upgrade-strategy only-if-needed aider-chat ``` Install verified 2026-09-30 (uv venv, Python 3.12.13, macOS arm64: `uv pip install aider-chat` ok, `import aider` ok, aider-chat 0.86.2. The docs' command adds `-U --upgrade-strategy only-if-needed`; the same package was installed without those flags. Packages came from the mirrors.aliyun.com mirror, so the version is the one that mirror served on this date. Install and import check only; not a functional test.). ```bash python -m pip install -U --upgrade-strategy only-if-needed aider-chat cd /path/to/your/project # interactive session with one model aider --model sonnet --api-key anthropic= # architect/editor: one model proposes, another writes the edits aider --architect --model o3-mini --editor-model sonnet \ --api-key openai= --api-key anthropic= # one-shot scripted edit, then exit aider --message "add docstrings to all functions" utils.py # inside the chat: /ask to discuss, /code to edit, /undo to revert the last commit ``` ### Common pitfalls - Plain pip installs support Python 3.9-3.12; the recommended `python -m pip install aider-install` then `aider-install` sets up a separate Python 3.12 environment for you. - Architect mode makes two LLM requests per turn, which the docs note is slower and costs more. - `--auto-accept-architect` defaults to on, so architect proposals are applied without an extra confirmation unless you disable it. - The Python scripting API (`aider.coders.Coder`) is not officially supported and may change. - The repository's last push was 2026-05-22 and the latest release is v0.86.0 (2025-08-09). Official quickstart: https://aider.chat/docs/install.html ## Pros - Apache-2.0 with no paid product; you only pay your model provider. ([source](https://github.com/Aider-AI/aider)) - Every AI edit is a normal git commit, so standard git tools can review and revert it. ([source](https://aider.chat/docs/git.html)) - Architect mode lets a reasoning-focused model plan while a different model writes the edits. ([source](https://aider.chat/docs/usage/modes.html)) - Works with almost any LLM, including local models. ([source](https://aider.chat/docs/llms.html)) ## Cons - No recent releases: the latest tagged release is v0.86.0 from 2025-08-09, and the last push to the repository was on 2026-05-22. ([source](https://github.com/Aider-AI/aider/releases)) - No MCP support; the feature request (issue #3314) remains open. ([source](https://github.com/Aider-AI/aider/issues/3314)) - A community PR adding MCP support (#3672) was closed without being merged. ([source](https://github.com/Aider-AI/aider/pull/3672)) - The Python scripting API is not officially supported or documented. ([source](https://aider.chat/docs/scripting.html)) - No documented multi-agent mode; architect mode is a two-model sequence that doubles LLM requests. ([source](https://aider.chat/docs/usage/modes.html)) ## Alternatives - [OpenCode](https://multiagentguide.top/tools/opencode.md) - [Cline](https://multiagentguide.top/tools/cline.md) - [Claude Code](https://multiagentguide.top/tools/claude-code.md) - [Codex CLI](https://multiagentguide.top/tools/codex.md) - [Gemini CLI](https://multiagentguide.top/tools/gemini-cli.md) ## FAQ ### Does aider support MCP? Not officially. MCP support is an open feature request (issue #3314), and an earlier PR to add it was closed unmerged. A2A and AG-UI are not documented either. ### Is aider free? Yes. Aider is Apache-2.0 open source with no paid tier; you pay only for the model API you use, or nothing with local models. ### Does aider have multiple agents or subagents? No. The closest feature is architect mode, where one model proposes changes and an editor model writes the file edits. ### Is aider still maintained? As of 2026-09-30 the repository is not archived, but the last push was on 2026-05-22 and the latest release is v0.86.0 from 2025-08-09. ### How is aider different from OpenCode? Aider is a single-agent, git-commit-centred terminal tool written in Python; OpenCode is a TypeScript agent with primary agents, subagents, MCP support and an HTTP server. ## Sources - [Aider-AI/aider repository (README)](https://github.com/Aider-AI/aider) - [Releases](https://github.com/Aider-AI/aider/releases) - [Release history](https://aider.chat/HISTORY.html) - [Issue #3314: MCP support](https://github.com/Aider-AI/aider/issues/3314) - [PR #3672: Add MCP support (closed, not merged)](https://github.com/Aider-AI/aider/pull/3672) - [Aider homepage](https://aider.chat/) - [Installation](https://aider.chat/docs/install.html) - [Chat modes (architect mode)](https://aider.chat/docs/usage/modes.html) - [In-chat commands](https://aider.chat/docs/usage/commands.html) - [Options reference](https://aider.chat/docs/config/options.html) - [Repository map](https://aider.chat/docs/repomap.html) - [Git integration](https://aider.chat/docs/git.html) - [LLMs](https://aider.chat/docs/llms.html) - [Linting and testing](https://aider.chat/docs/usage/lint-test.html) - [Watch mode (IDE comments)](https://aider.chat/docs/usage/watch.html) - [Scripting aider](https://aider.chat/docs/scripting.html) - [AG-UI README integration list](https://github.com/ag-ui-protocol/ag-ui) ## Unknown fields protocols.mcp: README and docs do not mention MCP; issue #3314 (open) requests it and PR #3672 was closed unmerged, with no maintainer statement found, so the status is unknown rather than no. protocols.a2a and protocols.agui: searched the README, the docs sources under aider/website/docs, GitHub issues and code search, and the AG-UI README integration list; nothing found. Corrections or removal requests: support@multiagentguide.top --- Data as of 2026-09-30. Not affiliated with listed projects. HTML version: https://multiagentguide.top/tools/aider