Harness support

super-backlog v1 supports two agent harnesses (design decision D1): OpenCode and Claude Code. sbl init targets both by default; use --harness opencode or --harness claude to restrict.

OpenCode — native

• opencode.json gets a merged plugin entry: "plugin": ["superpowers@git+https://github.com/obra/superpowers.git"]. Existing keys and other plugin entries are untouched; the entry is only added if the exact kit spec string is absent.
• The glue skills (spec-to-backlog, backlog-status-report, task-review-gate) are installed as files at .opencode/skill/<skill>/SKILL.md.

Claude Code — file-based skills + marketplace

• The same glue skills are installed file-based at .claude/skills/<skill>/SKILL.md — this always works, with or without CLI scripting support.
• A one-line pointer section is written to CLAUDE.md referencing the managed block in AGENTS.md.
• Marketplace installation: init does not run claude commands. After writing skills, it prints the exact command to paste inside Claude Code: /plugin install superpowers@claude-plugins-official. Because this step must be run manually, init pushes a warning (claude plugin install must be run manually) and finishes as success-with-warnings (exit code 4). File-based skills work immediately either way.

What is file-based vs. delegated

Artifact	Mechanism	Managed how
.opencode/skill/spec-to-backlog/	file-based, written by init	fingerprint header line
.claude/skills/spec-to-backlog/	file-based, written by init	fingerprint header line
opencode.json plugin entry	file-based merge into your config	byte-equality of entry
Superpowers runtime for OpenCode	delegated to OpenCode's plugin loader via the git-backed spec string	canonical spec string only
Superpowers marketplace install for Claude Code	instructed (manual one-time step)	init prints the exact command; never executed automatically
AGENTS.md workflow block	file-based injection	start/end markers
CLAUDE.md pointer	file-based append	recognized heading

The manifest is designed so later harnesses (Cursor, Codex, Gemini CLI — v2 backlog) can be added without changing the ownership model.