Parallax

OpenCode changes you can prove.

Parallax is an OpenCode plugin that turns every change into a verified loop: preflight → change → verify → receipt. Edits are gated until the agent states what it is doing and how it will know it worked. The project's own check runs on the edited files and leaves a durable receipt. Horizon extends the loop to long-running goals with a persisted plan, one delegated brief at a time, independent audits, and automatic continuation.

Requires Node 20+ and OpenCode 1.18.35+.

npx parallax-opencode@latest install
opencode

Restart OpenCode after the first install, then pick the parallax or horizon agent. Nothing is copied into your config directory: the installer adds one entry to opencode.json, and the agents and skills ship inside the package.

How it works

Step	What happens	Enforced by
Preflight	parallax_preflight records ambiguity, acceptance criteria, and invariants	file edits are rejected until it runs
Change	the agent edits; every touched file is tracked	tool.execute.after hook
Verify	parallax_verify runs the project check on the pending files and appends a receipt	a receipt is pass, fail, skipped, or unknown; only pass is evidence
Receipt	parallax_receipt closes with full, partial, hold, or override	refused while edits are unverified; full needs a passing receipt

The check is discovered, never configured: the first declared verify, test, typecheck, check, lint, or build script with the project's package manager; cargo check; go vet ./...; or python -m compileall. It runs without a shell, with a timeout, and with bounded output. The last failing output is injected into the system prompt until a later check passes.

State lives in .parallax/ (self-ignored by git):

.parallax/
├── config.json        optional
├── receipts.jsonl     every check, append-only
└── sessions/<id>.json preflight, pending files, decision

Configuration

Create .parallax/config.json only to change defaults. Unknown fields fail loudly.

{
  "strictness": "strict",
  "trivialPatterns": ["*.md"],
  "highRiskPatterns": ["src/auth/**"],
  "timeoutMs": 120000
}

Key	Default	Meaning
strictness	strict	strict: every non-trivial edit needs a preflight. standard: only files matching highRiskPatterns. relaxed: track only, never block
trivialPatterns	[]	globs that skip the gate (matched against the relative path or basename)
highRiskPatterns	[]	globs that always need a preflight
timeoutMs	120000	check timeout

Override agent models or permissions in opencode.json as with any agent; your values win:

{ "agent": { "horizon-worker": { "model": "provider/model" } } }

Skills

Loaded on demand with OpenCode's skill tool, so they cost nothing until needed: parallax-plan (scoped, verifiable plans), parallax-debug (evidence-led investigation), parallax-hyperplan (adversarial plan critique through parallel subagents).

Horizon

Horizon is a supervisor for goals that outlive one turn. It never edits code itself.

1. horizon_plan init and horizon_plan write persist a plan of milestones and atomic features under ~/.parallax/horizon/<plan>/.
2. For each feature Horizon dispatches one horizon-worker with task. The worker runs the Parallax loop and reports its receipt id.
3. horizon_feature receipt binds that receipt. The verdict is read from the ledger; the receipt must come from a horizon-worker session and from a fresh one per attempt.
4. Horizon dispatches one read-only horizon-auditor, which records its own verdict with horizon_feature audit. A pass receipt plus accept completes the feature; corrective reopens it with a rotating recovery directive (correct, replan, research, decompose).
5. With full autonomy the plugin re-prompts the Horizon session on session.idle while runnable work remains. User cancellation or a rejected permission pauses the plan, and so do six continuations without feature progress; the next real message or granted permission resumes it. horizon_feature block records typed blockers (credentials, external service, platform, framework, structural) with evidence.

The plugin enforces the shape: Horizon cannot edit, can only delegate to the two packaged roles, and runs one delegated task at a time; the worker cannot delegate or touch plans; the auditor cannot edit, run commands, or delegate. OpenCode permission prompts stay authoritative throughout.

Tools

parallax_preflight, parallax_verify, parallax_receipt, parallax_trace, horizon_plan, horizon_feature, horizon_note.

CLI

npx parallax-opencode install | uninstall | status | doctor | receipts [--json] [--config-dir <path>]

receipts summarizes .parallax/receipts.jsonl for the current project, useful in CI. install also removes files copied by versions before 1.0.

Development

npm ci --ignore-scripts
npm run check   # typecheck, tests, build, packed-artifact smoke, real OpenCode E2E

The E2E packs the module, installs it into a temporary prefix, launches the locked OpenCode binary with an isolated home and no credentials, and asserts the agents, permissions, tools, and skills it discovers.

MIT © Master0fFate