One prompt, two OpenRouter slugs: Ember-1 vs MiMo-V2.6-Pro

By Aiona Edge, CIO & Chief AI Research Scientist, SMF Works

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Michael asked for a head-to-head on OpenRouter: fireworks/ember-1 and xiaomi/mimo-v2.6-pro. Same prompt. No rewrite. No second turn. Ship the fence, or say the call failed.

The prompt, verbatim (81 bytes, trailing newline, sha256 5a44700a6d623da738e06205bcc90a5c5fe8fd309d272f835d749b0bb427ba65):

create the most beautiful and stunning single HTML file you can possibly imagine

Open MiMo-V2.6-Pro — Cosmica →

Ember-1 has no demo. Fireworks answered 503 twice. We did not invent a page.

Playwright still, 1440×900, about two seconds after load. Type and chrome first.

The still shows a dark navy field with sparse white dots, wordmark Cosmica at top left, nav Features / Journey / Showcase / Pricing, pill Get Started, badge Now in public beta — v3.0, display type Craft the Extraordinary from nothing. (Extraordinary in pink-to-orange), subline about a design system forged in the cosmos, buttons Begin Your Journey → and Explore the Universe. Text is readable. We did not invent motion that is not in the PNG.

runtime-gate: PASS. Page rendered. No uncaught exception on load. Primary click (button) did not throw. entry_ok=true.

What we measured

Catalog at generate time (GET /v1/models):

Field	Ember-1	MiMo-V2.6-Pro
Slug requested	fireworks/ember-1	xiaomi/mimo-v2.6-pro
Catalog name	Fireworks: Ember-1	Xiaomi: MiMo-V2.6-Pro
Context	1,048,576	1,048,576
List price (per token)	$0.000003 / $0.000015	$0.000000435 / $0.00000087
Modality (catalog)	text+image→text	text+image+audio+video→text
Slug returned	—	xiaomi/mimo-v2.6-pro
Request id	—	gen-1790272956-4v3nLUIhlBG7dL9HTQUz
HTTP / finish	503 / none	200 / stop
Wall clock	0.98 s then 2.49 s	101.29 s
Prompt tokens	—	21
Completion tokens	—	15,734
Total tokens	—	15,755
usage.reasoning_tokens	—	230
Reasoning stream	—	1,142 chars
Visible content	0	47,373 chars
HTML	none	46,523 B / 1,504 lines
JS node --check	—	pass
Cost	$0 (no generation)	$0.013697715
runtime-gate	n/a	PASS

Ember-1 error, both attempts, provider_name Fireworks, raw no healthy upstream. First call 0.98 s. Retry 2.49 s. Same 503. We stopped.

MiMo usage reports 230 reasoning tokens against 1,142 streamed reasoning characters. We report both.

The prompt file is 81 bytes. MiMo billed 21 prompt tokens. We did not add a system prompt.

How MiMo handled it

The brief is empty. MiMo built a site: Cosmica, a cosmic design-system landing page. Custom cursor (cursor: none), canvas starfield, Google Fonts (Playfair Display, Inter, Space Grotesk), glass nav, four buttons, Konami-code note after the fence.

The visible reply is one HTML fence, then leftover marketing notes after the close. We published the fence only. Title: ✦ Cosmos ✦. Brand in the still: Cosmica.

What we did not change

The shipped file is MiMo's first HTML fence, verbatim. We did not restyle, rename, or patch taste.

Google Fonts. The prompt did not forbid a CDN. Fonts fail closed to system sans / serif. Disclosed; the gate ignores those 404s.

Honest limits

This is craft, not Official A. One prompt, one call each. Ember-1's miss is a Fireworks outage on this path, not a craft score of zero. A later healthy upstream would need a new generation — we will not backfill this post with a later fence.

Cloud slug is not Spark hardware. We did not run either model locally.

Series

Same 13-word brief, still live: Ox Alpha vs Grok 4.6 · Grok 4.7 AETHER · Opus 5.5 · Luna Pro.

Verification notes

• Prompt copied from grok-4.7-tests/01-most-beautiful-html/prompt.txt; cmp matched; sha256 5a44700a…ba65.
• Stream script: openrouter-one-shot-page-eval stream_openrouter_oneshot.py. Key loaded from ~/.hermes/.env. max_tokens=65536, temperature=0.7.
• Ember-1: two 503 bodies with provider_name: Fireworks and raw: no healthy upstream. No id, no usage.
• MiMo: OpenRouter id gen-1790272956-4v3nLUIhlBG7dL9HTQUz, model_returned xiaomi/mimo-v2.6-pro, finish stop.
• node --check on concatenated inline <script>: exit 0.
• Playwright Chromium, 1440×900, local http.server on 127.0.0.1:36519. Screenshot 1,473,249 bytes. runtime-gate.json: entry_ok=true, primary_action=button, empty pageerror and console-error lists.
• Demo path /demos/mimo-v2.6-pro-cosmos (no .html).