OpenCode – Open source AI coding agent

Original Article ↗ Hacker News Discussion ↗

Overall sentiment

  • Many commenters like OpenCode as a flexible, open‑source “coding agent harness,” but a sizable group finds it buggy, resource‑hungry, and immature.
  • It’s widely used with multiple providers (OpenAI, Claude via API, Gemini, GLM, Kimi, Qwen, local models) and valued for sub‑agents, skills, and MCP integration.
  • Some say it has replaced other tools (Aider, Codex, Cursor‑style tools) for them; others have gone back to vendor tools (Claude Code, Codex, Gemini CLI).

Anthropic / Claude Code conflict & pricing

  • Claude subscription tokens are contractually restricted to Anthropic’s own tools; OpenCode is barred from using subscription auth, but can still use the Claude API at per‑token pricing.
  • Multiple users report Anthropic API costs as prohibitively high for heavy development; they see pricing as a way to push people into subsidized, lock‑in‑heavy subscriptions.
  • Some view OpenCode’s removal of first‑party Claude API integration as a principled response; others call it a “tantrum” and note API support was partially reintroduced via third‑party plugins.

Models, sub‑agents, and workflow

  • Strong appreciation for:
    • Assigning different models to sub‑agents (cheap “worker” models vs expensive planner/reviewer models).
    • Being able to switch providers easily (OpenAI, GLM, Kimi, Qwen, etc.) and use hosted open‑weights via OpenCode’s own plans.
    • MCP support and LSP integration for richer tool access and code understanding.
  • Some report large‑project struggles with certain models (e.g., GPT 5.4 “falls apart” on big repos).

Telemetry, privacy, and “local” claims

  • Serious concern that:
    • Web UI is proxied through opencode.ai rather than purely local.
    • A “small model” / Zen fallback previously sent prompts (e.g., for titles) to third‑party models without users realizing.
    • Config and plugins can be fetched from the web, raising RCE/privacy worries.
  • Maintainers and other commenters counter that:
    • The linked “telemetry” route is for serving the WebUI, not proxying all traffic.
    • Recent code paths now fall back to the main model when no small model is configured.
  • Behavior and defaults appear to have changed over time; several people mark the situation as trust‑eroding and “unclear” without careful version inspection or MITM tests.

Performance, stability, and architecture

  • Critiques:
    • Large, complex TypeScript codebase; often >1 GB RAM for a TUI.
    • Frequent releases, regressions, and memory leaks; some users abandoned it over instability.
    • TUI feels “overbearing” and not very Unix‑like; issues on some Linux setups.
  • Praise:
    • Very fast shipping of new features and fixes.
    • Good multi‑backend architecture (server, WebUI, desktop, VS Code integration).
    • Strong extensibility via plugins, skills, and agents.

Security & sandboxing

  • OpenCode has no built‑in sandbox; many users wrap it in containers, bubblewrap, or tools like nono, and bind‑mount or copy only the project directory.
  • Several argue any serious use should isolate agents from the full filesystem and credentials; others note this is true for all coding agents, not just OpenCode.

Comparisons & alternatives

  • Frequently compared tools: Claude Code (CLI and GUI), Codex, Gemini CLI, Aider, Crush, Pi, various Rust/Go‑based agents.
  • Codex and some Rust/Go tools are praised for far better performance and lower resource use.
  • Pi and others are praised for simplicity, small prompts, and being easier to extend; OpenCode is seen as more feature‑rich but heavier and more chaotic.