docs: update contributing guidelines and README for contribution support and provider details

- Announce support for contributions in `CONTRIBUTING.md`.
- Simplify and adjust submission guidelines, emphasizing focus and project alignment.
- Update README with new provider details, including Claude Code as the default provider.
- Add prerequisites for provider CLIs and git host integration in documentation.

Author: tyulyukov

.docs/codex-prerequisites.md

@@ -1,5 +1,19 @@
-# Codex prerequisites
+# Provider prerequisites
 
-- Install Codex CLI so `codex` is on your PATH.
+MarCode requires at least one of the following coding agent CLIs installed and authorized:
+
+## Claude Code CLI (default provider)
+
+- Install [Claude Code CLI](https://docs.anthropic.com/en/docs/claude-code) so `claude` is on your PATH.
+- Authenticate before running MarCode.
+
+## Codex CLI
+
+- Install [Codex CLI](https://github.com/openai/codex) so `codex` is on your PATH.
 - Authenticate Codex before running MarCode (for example via API key or ChatGPT auth supported by Codex).
-- MarCode starts the server via `codex app-server` per session.
+- MarCode starts the server via `codex app-server` per Codex session.
+
+## Git host CLIs (optional, for PR/MR features)
+
+- **GitHub:** Install and authenticate [GitHub CLI (`gh`)](https://cli.github.com/).
+- **GitLab:** Install and authenticate [GitLab CLI (`glab`)](https://gitlab.com/gitlab-org/cli). A Personal Access Token works for self-hosted instances.

.docs/provider-architecture.md

@@ -13,7 +13,7 @@ Methods mirror the `NativeApi` interface defined in `@marcode/contracts`:
 - `providers.respondToRequest`, `providers.stopSession`
 - `shell.openInEditor`, `server.getConfig`
 
-Codex is the only implemented provider. `claudeCode` is reserved in contracts/UI.
+Claude Code is the default provider. Codex is also supported as an alternative provider.
 
 ## Client transport
 

CONTRIBUTING.md

@@ -1,12 +1,6 @@
 # Contributing
 
-## Read This First
-
-We are not actively accepting contributions right now.
-
-You can still open an issue or PR, but please do so knowing there is a high chance we close it, defer it forever, or never look at it.
-
-If that sounds annoying, that is because it is. This project is still early and we are trying to keep scope, quality, and direction under control.
+We welcome contributions! MarCode is still early, so please read the guidelines below to keep things smooth.
 
 PRs are automatically labeled with a `vouch:*` trust status and a `size:*` diff size based on changed lines.
 
@@ -16,31 +10,25 @@ If you are an external contributor, expect `vouch:unvouched` until we explicitly
 
 Small, focused bug fixes.
 
-Small reliability fixes.
-
-Small performance improvements.
+Reliability and performance improvements.
 
 Tightly scoped maintenance work that clearly improves the project without changing its direction.
 
-## What We Are Least Likely To Accept
+New integrations or features that align with the project's goals (discuss in an issue first).
 
-Large PRs.
+## What We Are Least Likely To Accept
 
-Drive-by feature work.
+Large, unfocused PRs that mix unrelated changes.
 
-Opinionated rewrites.
+Opinionated rewrites without prior discussion.
 
 Anything that expands product scope without us asking for it first.
 
-If you open a 1,000+ line PR full of new features, we will probably close it quickly and remember that you ignored the clearly written instructions.
-
-## If You Still Want To Open A PR
-
-Keep it small.
+## Opening A PR
 
-Explain exactly what changed.
+Keep it small and focused.
 
-Explain exactly why the change should exist.
+Explain exactly what changed and why the change should exist.
 
 Do not mix unrelated fixes together.
 
@@ -54,12 +42,8 @@ If we have to guess what changed, we are much less likely to review it.
 
 If you are thinking about a non-trivial change, open an issue first.
 
-That still does not mean we will want the PR, but it gives you a chance to avoid wasting your time.
+This gives you a chance to align with the project direction before investing time.
 
 ## Be Realistic
 
-Opening a PR does not create an obligation on our side.
-
-We may close it. We may ignore it. We may ask you to shrink it. We may reimplement the idea ourselves later.
-
-If you are fine with that, proceed.
+We may close, defer, or ask you to rework a PR. We may also reimplement the idea ourselves later. That's the nature of early-stage projects — please don't take it personally.

README.md

@@ -1,28 +1,29 @@
 # MarCode
 
-MarCode is a minimal web GUI for coding agents (currently Codex and Claude, more coming soon).
+MarCode is a web GUI for coding agents, built as a rebrand and major evolution of [T3 Code](https://github.com/t3dotgg/t3code). On top of the original foundation, MarCode brings performance optimizations, new integrations, and a refined experience:
 
-## How to use
-
-> [!WARNING]
-> You need to have [Codex CLI](https://github.com/openai/codex) installed and authorized for MarCode to work.
-
-```bash
-npx marcode
-```
+- **Claude Code CLI** as the default and primary provider
+- **Jira Cloud integration** (OAuth 2.0, sprint browsing, `@PROJ-123` mentions in composer)
+- **GitLab support** alongside GitHub (auto-detected from remote origin)
+- **Preview diff display** for proposed file changes
+- **Incremental state updates** for smooth, non-blocking UI during agent work
+- **Additional directories in composer** — add extra directories to agent context per thread
+- And much more
 
-You can also just install the desktop app. It's cooler.
+## How to use
 
-Install the [desktop app from the Releases page](https://github.com/tyulyukov/marcode/releases)
+### Prerequisites
 
-## Some notes
+You need at least one of the following coding agent CLIs installed and authorized:
 
-We are very very early in this project. Expect bugs.
+- [Claude Code CLI](https://docs.anthropic.com/en/docs/claude-code)
+- [Codex CLI](https://github.com/openai/codex)
 
-We are not accepting contributions yet.
+For git host integration:
 
-## If you REALLY want to contribute still.... read this first
+- **PRs (GitHub):** [GitHub CLI (`gh`)](https://cli.github.com/) installed and authenticated
+- **MRs (GitLab):** [GitLab CLI (`glab`)](https://gitlab.com/gitlab-org/cli) installed and authenticated (Personal Access Token works for self-hosted instances)
 
-Read [CONTRIBUTING.md](./CONTRIBUTING.md) before opening an issue or PR.
+### Via Desktop App
 
-Need support? Join the [Discord](https://discord.gg/jn4EGJjrvv).
+Install the [desktop app from the Releases page](https://github.com/tyulyukov/marcode/releases)