LevelCode v1.0.0

LevelCode v1.0.0

LevelCode reaches 1.0 — running Anthropic's frontier model. Claude Opus 5 is now a first-class pick: in your roster if you're on a LevelCode Cloud plan, or in the OpenRouter list if you bring your own key — wired at its full 1M-token context and priced exactly where Opus 4.8 sat.

The 0.9 line built the parts — the agent loop, apply-then-review edits, the browser that opens itself, credits instead of dollars. 1.0 is that foundation, stable, running on Opus 5.

Highlights

Claude Opus 5

Opus 5 is Anthropic's newest frontier model, and LevelCode reaches it two ways:

• On a LevelCode Cloud plan, it's already in your roster. Models come from the server, so Opus 5 shows up without updating the editor, metered in credits like everything else — roughly 195 Opus 5 turns on the top plan's 10,000 credits.
• Bring your own OpenRouter key and it's in the picker. Claude Opus 5 — Anthropic · frontier, 1M · via OpenRouter, near the top of the OpenRouter list. Your key, billed by OpenRouter; the editor shows a cost estimate rather than a credit balance.

Two things it gets right that a bare model id wouldn't:

• The full 1M-token window. LevelCode's context heuristic assumes 200K for any claude- model; left at that, the in-run context meter would warn "full" at a fifth of Opus 5's real budget. Opus 5 has an explicit 1,000,000-token caps row, so the meter reflects the window you actually have.
• Honest pricing, whichever slug you type. Opus 5 costs what Opus 4.8 did — $5 / M in, $25 / M out, cached reads at $0.50 / M — so the OpenRouter "powerful" tier moved to the newer model for the same money, and prompt caching is on so repeated context bills at the cached rate. The fast variant is double ($10 / $50 per M); its price is pinned explicitly so the estimate can't quietly under-report it by half.

Your whole roster on the first open

Opening LevelCode with a briefly-expired Cloud token used to collapse the model picker to a two-model fallback — you'd see two models on a plan that offers the full lineup, and only a reopen fixed it. The roster fetch now refreshes the token and retries, and if anything still fails it keeps the last-known-good list rather than discarding it. You get your full roster on the first try.

Under the hood

• 1M context, measured — not guessed. Opus 4.8 on OpenRouter is also a 1M-window route, so its caps row was split by route: the OpenRouter slug reports 1M, the bare Anthropic id stays at 200K. We deliberately did not raise the native path to 1M — this editor sends no anthropic-beta header there, so the long window isn't confirmed reachable, and promising room the API would refuse is the worse failure. Each route reports its own truth.
• The "powerful" OpenRouter tier now names a model the registry knows. The old Opus 4.8 slug never was in it, so a per-node model override pointing there failed validation and fell back silently; moving the tier to Opus 5 fixes that as a side effect.
• Release builds moved off the deprecated Node 20 runtime. GitHub had begun force-running the release actions on Node 24 with a per-step warning; the action pins now target Node 24 natively.

Test coverage

• 24 suites across the bundled extensions, all green on every release.
• catalog.test.js (13 cases) pins both sides of the 1M split — the OpenRouter slug at 1,000,000, the bare id at 200,000 — plus the heuristic default for an unlisted Claude model, so the context meter can't silently regress. sketch.test.js (16 cases) pins Opus 5's pricing, including the fast variant the family fallback would otherwise have billed at half.

Full changelog: v0.9.2...v1.0.0