opencode-smol

opencode-smol

Small · Minimal · Optimal · Light

A token-frugal opencode plugin for solo developers.

smol is a complete agent workflow in one tiny package: planning, TDD-enforced coding, multi-lens review, codebase mapping, and persistent project memory. No bloat, no over-engineering, no monthly token bill shock.

Why smol

Mainstream agent frameworks (superpowers, gsd, gstack) are built for teams. As a solo developer you do not need 23 specialist roles, a spec-first pipeline, or thousands of lines of methodology prose.

You need:

• A short brainstorm before you code.
• Real TDD enforcement (RED → GREEN, no skipping).
• A code review pass that catches the things you would rationalize away.
• A persistent memory of this project so the AI does not re-learn it every session.

That is what smol is. Each agent prompt is under 2.5 KB. The whole plugin is roughly the size of a single superpowers SKILL.

What you get

6 slash commands

Command	What it does
/smol-plan	Brainstorm → plan markdown saved under .smol/plans/
/smol-build	Run the next atomic task in TDD style
/smol-fast	One-shot: small change, no plan needed
/smol-review	Multi-lens review (correctness + security + minimalism in parallel)
/smol-auto	Conductor drives the full plan → code → review pipeline non-stop
/smol-map	Build / refresh the per-folder codemap

6 agents

Agent	Role	Mode
Conductor	Default primary. Understands intent, delegates, verifies.	primary (replaces build as default)
Planner	Stage-based brainstorming → atomic plan.	primary (replaces plan)
Coder	TDD-only. Iron law: no production code without a failing test.	subagent
Reviewer	Severity-tagged [C]/[I]/[M] review. Accepts a Lens: for parallel multi-angle review.	subagent
Mapper	Maintains .smol/codemap.{json,md}.	subagent
Scout	External research via context7 + exa MCP, parallel sources.	subagent

The built-in build agent is kept (so you can still use it explicitly); the built-in plan is hidden because Planner replaces it.

3 native tools

Agents prefer these over shell commands — schema-validated, no parsing.

Tool	Args	Purpose
smol_codemap	action: init | update | changes	Maintain .smol/codemap.json and per-folder codemap.md
smol_wiki	kind: memory | preferences | pitfalls, entry: string ≤200	Append a dated entry, dedups
smol_plan	topic: string, content: string	Write .smol/plans/YYYY-MM-DD-<slug>.md

3 hooks

• session.start — injects a one-line prompt so the LLM checks .smol/wiki/ and .smol/codemap.md when relevant.
• session.compacting — re-injects codemap + latest plan so project memory survives long sessions.
• session.created — bootstraps .smol/wiki/ skeleton on first run.

codemap CLI

A standalone incremental code-mapper bundled with the plugin. Runs locally, no LLM calls, computes per-folder summaries with content hashes so re-runs only touch changed folders.

Install

Add to your opencode.json (project root or ~/.config/opencode/):

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-smol"]
}

Restart opencode. The 6 commands, 6 agents, skills, tools and hooks are all live. No CLI, no file copying, no config edits beyond the line above.

Quick start

/smol-map        # one-time: build codemap of your project
/smol-plan       # describe what you want to build
/smol-auto       # let conductor drive plan → code → review

Or step through manually:

/smol-plan
/smol-build      # runs the next atomic task
/smol-build
/smol-review     # before committing

For tiny changes, skip planning:

/smol-fast "rename foo to bar in handlers/"

Per-agent model config

Every smol agent ships with a free default: opencode/big-pickle, so the plugin works out of the box even without a paid subscription. To override per agent, create .smol/smol.json:

{
  "agents": {
    "conductor": { "model": "anthropic/claude-sonnet-4-5", "variant": "high" },
    "planner": "openai/gpt-5-mini",
    "coder": { "model": "anthropic/claude-haiku-4-5" },
    "reviewer": { "model": "openai/gpt-5" }
  }
}

A bare string is shorthand for { "model": "..." }. Unknown fields (such as variant) are passed through to opencode's agent config.

Layout it creates

.smol/
├── codemap.json
├── codemap.md
├── <subdir>/codemap.md
├── plans/YYYY-MM-DD-<topic>.md
└── wiki/
    ├── memory.md       # patterns and conventions of this project
    ├── preferences.md  # explicit user preferences
    └── pitfalls.md     # bugs / gotchas / workarounds

Add .smol/ to .gitignore if you do not want to commit project memory; commit it if you do (recommended for shared codebases).

Parallelism

smol uses opencode's built-in task tool for parallel subagent dispatch — no extra runtime, no background daemon.

• Parallel review: /smol-review fires three reviewer subagents in one message (Lens: correctness, Lens: security, Lens: minimalism), then the Conductor synthesizes one report.
• Parallel research: when a question has independent sub-parts, Conductor dispatches multiple Scouts at once.
• Coder is never parallelized — TDD requires one RED → GREEN cycle at a time.

Worktree usage

smol intentionally does not ship a worktree implementation. If you want isolated parallel branches, install opencode-worktree alongside it and add a hint in your project's AGENTS.md describing when the Conductor should reach for it. Two small, focused plugins, zero overlap.

Comparison

	smol	superpowers	gsd	gstack
Total methodology size	~15 KB	~150 KB	~80 KB	~120 KB
Agents	6	1 (skill-based)	11+	23
TDD enforced	yes (iron law)	yes (skill)	partial	partial
Persistent project memory	yes (.smol/wiki)	no	partial	no
Codemap (token-saving)	yes (.smol/codemap)	no	no	no
Per-agent model + variant	yes	n/a	yes (stage)	n/a
Solo-developer fit	★★★	★★	★	★

Philosophy

See SPEC.md. Short version:

• Most agent frameworks are built for teams; solo work needs less.
• Methodology embedded in agent prompts, not floating skill files.
• Only the rules that get rationalized away under pressure are enforced as "iron laws".
• Wiki and codemap give the project a memory so the AI does not re-discover it every session.
• Stay out of the way otherwise.

Development

npm install
npm test

42 tests across codemap, plugin hooks, config, and tools.

License

MIT