OpenCode

OpenCode (sst/opencode) is SST's open-source CLI agent — terminal-native, similar feel to Claude Code.

Get an API key first — see Common setup.

Install

# All platforms (needs Node 18+)
npm install -g opencode-ai
# or: bun install -g opencode-ai
opencode --version

Config file location

OS	Path
macOS	~/.config/opencode/opencode.json
Linux	~/.config/opencode/opencode.json
Windows	%APPDATA%\opencode\opencode.json (i.e. C:\Users\<you>\AppData\Roaming\opencode\opencode.json)

Create and edit

macOS / Linux

mkdir -p ~/.config/opencode
vim ~/.config/opencode/opencode.json

Windows PowerShell

New-Item -ItemType Directory -Force -Path "$env:APPDATA\opencode" | Out-Null
notepad "$env:APPDATA\opencode\opencode.json"

Paste this in (swap in your key):

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "primerouter": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "PrimeRouter",
      "options": {
        "baseURL": "https://primerouter.ai/v1",
        "apiKey": "sk-your-primerouter-key"
      },
      "models": {
        "gpt-5.5":           { "name": "GPT-5.5"           },
        "gpt-5.4":           { "name": "GPT-5.4"           },
        "claude-opus-4-8":   { "name": "Claude Opus 4.8"   },
        "claude-opus-4-7":   { "name": "Claude Opus 4.7"   },
        "claude-opus-4-6":   { "name": "Claude Opus 4.6"   },
        "claude-sonnet-4-7": { "name": "Claude Sonnet 4.7" },
        "claude-sonnet-4-6": { "name": "Claude Sonnet 4.6" }
      }
    }
  }
}

Launch and pick model

opencode
# Inside the TUI: /model
# Pick primerouter/claude-sonnet-4-6 (or one of the others)

Alternative: interactive login

opencode auth login
# Choose "Other / Custom" or "OpenAI Compatible"
# Base URL: https://primerouter.ai/v1
# API Key:  sk-your-primerouter-key

Editing JSON is better for managing multiple models; interactive login is best for a single model.