Match the sign-in you have to the surface that page documents, then keep project rules in the file that page reads. OpenCode’s intro is the documented path for a provider API key, including the OpenCode Zen sign-in, and for the AGENTS.md file that /init writes after a provider is configured. Claude Code’s overview is the documented path for a Claude subscription or an Anthropic Console account on the surfaces that require them, for a paid subscription on the desktop app, and for standing rules in CLAUDE.md. The overview says Claude Code can read an existing AGENTS.md on its own or alongside CLAUDE.md. A changelog note says that in a project with no CLAUDE.md, Claude Code reads AGENTS.md instead. These pages describe that shared filename with different read rules, and they leave speed, quality, and price unranked.
Sign-in, surfaces, and project files
The choice these pages document is which account each surface expects, where the tool runs, which command installs it, and which markdown file carries project rules. Speed, answer quality, and price stay outside that choice.
The Claude Code overview describes an agentic coding tool that reads your codebase, edits files, runs commands, and integrates with development tools, in the terminal, an IDE, a desktop app, and a browser. The same page calls it an AI-powered coding assistant for building features, fixing bugs, and automating development tasks across files and tools. The OpenCode intro calls OpenCode an open-source AI coding agent available as a terminal interface, a desktop app, or an IDE extension.
The desktop app on the Claude Code overview requires a paid subscription. That tab also says the app includes Claude Code, so the desktop path uses the app install. Desktop downloads on the page cover macOS, Windows x64, and Windows ARM64, plus a beta apt path on Ubuntu or Debian. The web surface starts at claude.ai/code with no local setup, on desktop browsers and the iOS and Android app. OpenCode’s intro names a desktop app and an IDE extension. Their install steps sit outside this intro.
Documented setup differences from the OpenCode intro, the Claude Code overview, and the Claude Code changelog, checked 28 September 2026
| Setup choice | OpenCode intro | Claude Code overview |
| — | — | — |
| Account | Any LLM provider, by configuring API keys. For newcomers, the intro recommends OpenCode Zen, which it calls a curated list of models the OpenCode team has tested and verified. | Most surfaces require a Claude subscription or an Anthropic Console account. The terminal, VS Code, and JetBrains also support third-party providers. The desktop app requires a paid subscription. |
| Surfaces with steps on the page | Terminal install and first-run steps. A desktop app and an IDE extension are named. Terminal use expects a modern emulator. The intro lists WezTerm and Alacritty as cross-platform, and Ghostty and Kitty for Linux and macOS. It also expects API keys for the providers you want. | Terminal, VS Code (with an install link for Cursor), JetBrains (IntelliJ IDEA, PyCharm, WebStorm, and other JetBrains IDEs), the desktop app, and the web at claude.ai/code. JetBrains requires the CLI, installed separately. |
| Project instructions | /init, typed inside OpenCode after a provider is configured, writes AGENTS.md at the project root. | CLAUDE.md is read at the start of every session. An existing AGENTS.md can be read on its own or alongside CLAUDE.md. A changelog note: in a project with no CLAUDE.md, Claude Code reads AGENTS.md instead. |
| Feature workflow | The intro recommends creating a plan before adding a feature, then switching back to Build mode to make the changes. For a more straightforward change, it also shows asking OpenCode to build that change directly, before a plan review. | For a feature, the overview says Claude Code plans the approach, writes the code across multiple files, and verifies it works. For a bug, it says Claude Code traces the issue and implements a fix. |
| Plan mode control | Tab turns on Plan mode, which disables changes and suggests an implementation. An indicator appears in the lower right. Tab again returns to Build mode. | A changelog note for the VS Code extension adds a typed /plan that switches to plan mode, sends a first planning prompt, or shows the session’s plan. |
For OpenCode, the intro’s easiest install is curl -fsSL https://opencode.ai/install | bash. Configure says to type /connect in the terminal UI after OpenCode is open, then choose the menu entry named opencode, sign in at opencode.ai/auth, add billing details, and paste the API key. The menu entry named opencode is the Zen provider in /connect. The shell command opencode comes later, in Initialize. The intro mentions billing details and states no amounts. Initialize starts once a provider is configured. It prints cd /path/to/project, then the shell command opencode, then /init. /init writes AGENTS.md at the project root.
For Claude Code, the overview’s recommended native install is curl -fsSL https://claude.ai/install.sh | bash on macOS, Linux, and WSL; irm https://claude.ai/install.ps1 | iex in Windows PowerShell; and curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd in Windows CMD. If the shell says && is not a valid statement separator, use the PowerShell line. If the shell says irm is not recognized, use the CMD line. The prompt shows PS C:\ in PowerShell and C:\ without PS in CMD. After the installer finishes, open a new terminal and run claude –version. A working installation prints a version number. If the shell says claude is not found, the install directory is not on PATH yet. Native installs update in the background.
The overview’s printed Homebrew install is brew install –cask claude-code. The overview says the claude-code cask tracks the stable channel, typically about a week behind and skipping releases with major regressions, and that the cask name claude-code@latest tracks the latest channel and receives new versions as soon as they ship. Homebrew installs do not auto-update. The printed upgrades are brew upgrade claude-code or brew upgrade claude-code@latest, depending on which cask you installed. WinGet’s printed install is winget install Anthropic.ClaudeCode. WinGet installs do not auto-update, and the printed upgrade is winget upgrade Anthropic.ClaudeCode.
Then cd into the project and run claude. First use prompts for login. If ANTHROPIC_API_KEY is already set, Claude Code skips the login prompt and asks you to approve the key. On native Windows, the overview recommends Git for Windows so Claude Code can use the Bash tool. If Git for Windows is not installed, the overview says Claude Code uses PowerShell as the shell tool. WSL setups do not need Git for Windows. A changelog note says Git for Windows is no longer required, and that Claude Code uses PowerShell when it is absent. Put standing rules in CLAUDE.md. The overview says Claude Code can read an existing AGENTS.md on its own or alongside CLAUDE.md. A changelog note says that in a project with no CLAUDE.md, Claude Code reads AGENTS.md instead. The desktop app requires a paid subscription. These pages state no subscription prices and no OpenCode Zen amounts. Check the figures in your own account.