OpenRouter added a new stealth model on August 20, 2026: Ox Alpha (stealth/ox-alpha) — positioned as a frontier-class model for efficient coding, sustained agentic work, and production workloads, with a 1M-token context window, multimodal input, tool calling, and $0/$0 pricing during preview.
The release lands one day after AT&T reported 56% coding-cost savings from model routing and in the same week Stripe's investor letter named OpenRouter its largest-ever acquisition — still expected to close in the coming weeks. Ox Alpha is not about that deal; it is a concrete model you can point an agent harness at today, for free, through the same OpenRouter API many teams already use for Fusion panels and cost-aware routing.
TL;DR — what builders are asking
| Question | Direct answer |
|---|---|
| Model ID? | stealth/ox-alpha |
| Released? | August 20, 2026 (per OpenRouter model page) |
| Price? | Free — $0/M input, $0/M output |
| Context / max output? | 1,048,576 tokens in · 131,072 tokens out |
| Modalities? | Text, images, and video in → text out |
| Tool calling? | Yes — supported; OpenRouter reports ~4.45% tool-call error rate (3-day avg) |
| Throughput / latency? | ~50 tok/s and ~2.02s P50 latency (OpenRouter dashboard) |
| Trains on your data? | OpenRouter says prompts/completions are retained but not used for training (this release) |
| Who made it? | Anonymous third-party provider — identity not disclosed |
| Top agent traffic? | Claude Code (~9.3B tokens), Hermes Agent (~9.0B), plus Oh-My-Pi, DeepSeek Harness, Z Code on the model's apps chart |
What OpenRouter stealth models are
OpenRouter's stealth models are preview releases from third-party providers who stay anonymous during the preview window. OpenRouter routes traffic; it does not develop or own the weights.
The pattern is established:
- Models ship under codenames (
Ox Alpha, past examples include Hunter Alpha, Healer Alpha, Owl Alpha). - They are often free during preview to drive eval traffic.
- Providers historically logged prompts for improvement — Ox Alpha's page makes a narrower claim for this release (more below).
- OpenRouter later reveals some identities — Hunter and Healer turned out to be Xiaomi MiMo models. Ox Alpha has no official reveal yet.
Governance falls under OpenRouter's Stealth Model Terms — separate from standard provider terms. Treat stealth previews as time-boxed experiments, not long-term infrastructure commitments.
Ox Alpha specs (verified from OpenRouter)
These numbers come from the Ox Alpha model page as of August 21, 2026:
| Spec | Value |
|---|---|
| Model slug | stealth/ox-alpha |
| Provider label | Stealth (single upstream host) |
| Listed price | $0 / $0 per million tokens |
| Context window | 1,048,576 tokens |
| Max output | 131,072 tokens |
| Input modalities | Text, image, video |
| Output | Text |
| Reasoning | Supported (reasoning parameter documented) |
| Tool calling | Supported |
| Release date | August 20, 2026 |
| Cache hit rate (3d avg) | ~67% |
| Uptime (3d) | 99.99% |
| Availability (3d) | 96.79% |
OpenRouter's description emphasizes long-horizon software engineering, complex reasoning, and workflows that combine text with visual context — language that matches how agent harnesses actually burn tokens: repo maps, screenshots, test logs, and multi-step tool loops.
Who is already using it
OpenRouter publishes app-level token share for each model. On Ox Alpha's first days, the leaderboard is dominated by agent harnesses, not chat UIs:
- Claude Code — Anthropic's agentic coding tool (~9.32B tokens on the model chart)
- Hermes Agent — Nous Research's persistent open-source agent (~8.98B tokens)
- Oh-My-Pi, DeepSeek Harness, and Z Code — also listed among top senders on the model page
That traffic mix is a signal: teams running real coding agents are treating Ox Alpha as a workhorse model, not a playground curiosity. It does not prove quality on your repo — only that production-shaped workloads are flowing.
Free pricing and the "no training" claim
Two details matter for anyone routing proprietary code through Ox Alpha.
Free — for now
OpenRouter lists Ox Alpha at $0/$0. Stealth previews have historically been free to accumulate feedback, then either graduate to a named model with list pricing or disappear. Budget for the possibility that "free" is a preview subsidy, not a permanent tier — the same caution AI token pricing guides apply: watch usage dashboards and keep fallback routes.
Retention ≠ training (read both lines)
OpenRouter's Ox Alpha banner states:
Prompts and completions for this model are retained by the provider and are not used for training; all other use is governed by the Stealth Model Terms.
That is a meaningful distinction:
| Claim | What it implies | What it does not imply |
|---|---|---|
| Not used for training | Provider says your completions won't fine-tune weights (this release) | Prompts aren't stored |
| Retained by the provider | Logs likely persist on provider infrastructure | You know who the provider is |
| Stealth Model Terms | Other uses (eval, abuse monitoring, legal holds) may still apply | Enterprise ZDR / HIPAA |
For production secrets, an anonymous provider with retained logs is a different risk profile than calling Anthropic or OpenAI under a signed enterprise agreement — even when the sticker price is zero. The Databricks cost post and AT&T routing story both assume internal evals and tiered routing precisely because model substitution is never just a price question.
Who is Ox Alpha? (verified unknown + community rumors)
Verified: OpenRouter does not disclose Ox Alpha's origin. The provider chose anonymity for this preview. OpenRouter is explicit that it is not the developer.
Unverified community speculation — treat all of the following as rumor, not sourcing:
- GLM-based (Zhipu) — some observers cite speed, time-to-first-token, and cache behavior as GLM-like
- Claude-derived — occasional claims of "stolen checkpoint" with no primary evidence
- Gemini Flash ensemble — shorthand like "three Gemini flashes" with no official confirmation
- Chinese lab guesses (Tencent, Xiaomi) — pattern-matching from past stealth reveals, not proof
Past stealth models were unmasked (Xiaomi MiMo for Hunter/Healer). Ox Alpha may follow that path — or ship under a public name on another host first. Do not architect compliance around guessed identity. Run evals on behavior, log retention, and your own policy constraints.
How to try Ox Alpha via the OpenRouter API
OpenRouter's API is OpenAI-compatible. Swap the base URL and model slug.
1. API key
export OPENROUTER_API_KEY="sk-or-v1-..."
Create keys in the OpenRouter dashboard.
2. Minimal curl (non-streaming)
curl https://openrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $OPENROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "stealth/ox-alpha",
"messages": [
{"role": "user", "content": "Refactor this function to handle nil inputs safely."}
]
}'
3. Agent harness / Claude Code / Hermes
Point your harness provider at OpenRouter and set the model to stealth/ox-alpha. Optional headers (HTTP-Referer, X-Title) only affect OpenRouter leaderboard attribution — not model behavior.
For tool-heavy loops, enable streaming and watch cumulative latency: OpenRouter reports ~11.6s median end-to-end latency on multi-step agent turns — acceptable for background agents, painful for tight interactive edits unless you route subtasks to faster tiers.
4. Routing pattern (recommended)
Mirror enterprise playbooks from AT&T's LiteLLM gateway:
cheap/open route (Ox Alpha) → internal eval gate → premium model on failure
Ox Alpha is a strong candidate for the cheap tier while it stays free — not a blind default for merges, security reviews, or regulated data.
What people are asking
Is Ox Alpha actually "frontier"?
OpenRouter's marketing calls it frontier-class for efficient coding and agentic work. There is no independent benchmark sheet on the model page — only usage stats and latency. Community threads compare it favorably to some Chinese open models and note fast tool use, but your golden tasks (lint fixes, migrations, test generation) are the only eval that matters.
Will it stay free after Stripe closes the OpenRouter deal?
Unknown. Stripe's acquisition is not closed yet; Ox Alpha pricing is set by the anonymous provider + OpenRouter listing, not by Stripe today. Watch the model page and your invoice — free stealth previews can change overnight.
Ox Alpha vs OpenRouter Fusion
| Ox Alpha | OpenRouter Fusion | |
|---|---|---|
| Shape | Single stealth model | Multi-model panel + judge |
| Cost | Free (preview) | Sum of panel + judge tokens |
| Best for | High-volume agent loops, coding | Research, deliberation, high-stakes synthesis |
| Identity | Anonymous | Named panel models |
They solve different problems. Fusion is for when being wrong is expensive; Ox Alpha is for when token volume is expensive — at least while the preview lasts.
Should I send customer PII or prod secrets?
No — not to an anonymous stealth provider that retains logs. Use Ox Alpha for sanitized repos, open-source work, or spikes where log retention is acceptable. Same rule as any free preview tier.
Bottom line
Ox Alpha is real, free, and already carrying billions of tokens from Claude Code and Hermes Agent — verified on OpenRouter's dashboard. Who built it is not verified; GLM, Claude, and Gemini rumors are community noise until OpenRouter or the provider says otherwise. The actionable move for developers: add stealth/ox-alpha as a routed tier, run your coding evals, and treat retention + anonymity as the limiting factor — not the $0 price tag.
Related on explainx.ai
- Stripe acquires OpenRouter — what builders should know
- AT&T cut AI coding costs 56% with model routers
- Databricks: managing AI coding costs at scale
- OpenRouter Fusion API guide
- Hermes Agent #1 on OpenRouter rankings
- AI token pricing, explained
- Choosing open-weight vs closed models
- OpenRouter · Loop engineering with coding agents
Primary sources: OpenRouter — Ox Alpha model page · OpenRouter — Stealth provider · OpenRouter — Stealth Model Terms
Accurate as of August 21, 2026. Stealth previews can change pricing, limits, or availability without notice. Community identity guesses are unverified unless OpenRouter publishes a reveal. Follow @explainx_ai for updates.