Spec-driven builds with sandboxed AI coding agents.
Write numbered specs, then overplane build: each spec is raised to a formal
IR checked with Z3, and code is generated by a CLI coding agent of your choice
running in an ephemeral container sandbox, with per-step cost and token
reporting.
npm install -g overplane # npm wrapper (downloads the release binary)
go install github.com/overplane/overplane/cmd/overplane@latestOr grab a signed binary for your platform from the download page, the npm package, or the latest release. Requires Docker (Buildx ≥ 0.13) or Podman 5.x for sandboxed builds.
| Section | What's there | Jump to |
|---|---|---|
| Getting started | Zero-to-first-build walkthrough | requirements · install · first spec · build |
| CLI reference | Every command, flag, and exit code | global flags |
| Configuration | The overplane.yaml schema, field by field |
|
| Sandbox & agents | Container images, mounts, and agent wiring | supported agents · mounts · image recipes |
| Spec format | Numbered Markdown specs + YAML frontmatter | |
| Examples | Real projects built by agents, with cost benchmarks | |
| Overview | What Overplane is, in five reading styles | |
| Download | Binaries for all platforms, checksums, cosign |
overplane agent drives four CLI coding agents headlessly behind one
vendor-agnostic abstraction; see the
Agent reference.
| Agent | Binary | Auth env | Cost source |
|---|---|---|---|
| Claude Code | claude |
ANTHROPIC_API_KEY |
reported |
| OpenAI Codex | codex |
CODEX_API_KEY / OPENAI_API_KEY |
computed |
| Google Gemini CLI | gemini |
GEMINI_API_KEY |
computed |
| OpenCode | opencode |
OPENROUTER_API_KEY |
reported |
Default OpenCode model: openrouter/z-ai/glm-5.2 (GLM-5.2 via OpenRouter).
Gemini stays on the headless Gemini CLI; Antigravity is deferred (browser-OAuth, no headless mode as of 2026-06). Cost is reported by the backend where available, else computed from an advisory per-model price table.