Ox Alpha free preview ended: what it became and what to use now

Update, August 27, 2026: The free preview has ended. OpenRouter now identifies Ox Alpha as Z.ai GLM-5.3-Flash, and OpenCode Zen no longer lists x-preview-f-free. The configuration below is preserved for editorial history and should not be treated as a live deal or current setup guide.

Ox Alpha appeared without a named developer, a model card, or a launch blog from the lab that built it. During its short preview it offered a million-token context window, tool calling, multimodal input, and a zero-dollar token price on two coding gateways.

The official name was Ox Alpha, with the letter O. You may also see it written as “0x Alpha” in older posts and searches. Its former model IDs were:

OpenRouter: stealth/ox-alpha
OpenCode Zen API: x-preview-f-free
OpenCode model picker: opencode/x-preview-f-free

OpenCode announced on August 20 that the model would be free for “the next week.” That pointed to roughly August 27, but neither gateway published an exact cutoff hour. Both catalogs still showed zero token pricing on August 26; by August 27, OpenRouter had changed to a retrospective identification page and Zen had removed the route. That is why the deals inventory records the preview as ended without inventing a calendar expiry.

What the preview established

Claim	Evidence status	Practical meaning
1,048,576-token context and up to 131,072 output tokens	Published by OpenRouter’s live model API	Enough capacity for large repository selections, logs, and tool history; not proof of perfect million-token recall.
Text, image, and video input; text output	Published by OpenRouter	Useful for code, screenshots, and visual debugging when the coding harness passes those inputs correctly.
Tool calling and reasoning controls	Published in OpenRouter’s supported-parameter list	The model can participate in agent loops, but reliability still depends on the harness and gateway translation.
Free on OpenRouter and OpenCode Zen	Confirmed on August 26; ended by August 27	The zero-token price was temporary and is no longer a live offer.
Built by Z.ai or part of the GLM family	Revealed after the preview	OpenRouter now identifies Ox Alpha as Z.ai GLM-5.3-Flash.
Better than a current frontier coding model	Not established	One successful demo or bug fix is a reason to test, not a general ranking.

Our Ox Alpha review and video companion documents the strongest observed signal so far: in Ron’s Helm’s Deep test, the model changed tactics when its first approach failed and finished with roughly 200,000 tokens. Comparable channel runs often used much more, but this was not a matched multi-run evaluation. Treat the recorded run as useful evidence, not an invented vendor scorecard.

Pick the route before you configure the app

The same model name does not mean the same service conditions.

Former route	Best use during the preview	Published free access at the time	Published data handling at the time	Catch
OpenCode + Zen	Fastest supported setup and heavier trial use	x-preview-f-free was free for a limited time	Zen said this route was zero retention and not used for model training	Zen required billing details; its current model table no longer lists this route.
Claude Code + OpenRouter	Simplest direct Claude Code connection	stealth/ox-alpha showed $0 input/output	OpenRouter said the anonymous provider retained prompts and completions but did not train on them	The model page is now retrospective rather than a live zero-price offer.
Claude Code + CC Switch + Zen	Claude Code interface with Zen’s preview route	Zen kept the route free during the preview	Zen published zero retention for Ox Alpha	Required CC Switch’s local routing service to translate Anthropic Messages to OpenAI Chat Completions.

During the preview, OpenCode with Zen was the most direct route, OpenRouter was the shortest Claude Code connection, and CC Switch preserved Claude Code’s interface through a local protocol-conversion layer. Those routes are documented below as an archive, not as current instructions.

Route 1: try Ox Alpha in OpenCode

OpenCode Zen is the route the OpenCode team has tested for its own coding harness.

1. Sign in to the official OpenCode Zen console. Zen’s documentation says account setup includes billing details even when the selected model is free.
2. Before adding credits, inspect auto-reload and the workspace monthly limit. Zen says auto-reload can add $20 when a balance drops below $5 unless you change or disable it.
3. Install or open OpenCode, then enter /connect in the TUI.
4. Choose OpenCode Zen and paste the API key locally.
5. Run /models and select Ox Alpha Free, whose configuration ID is opencode/x-preview-f-free.
6. Start with a small read-only request: “Inspect this repository, identify the test command, and propose one bounded task. Do not edit files.”

Check the model shown in the session before granting edit or terminal permissions. “Free” should not turn into accidental use of a paid fallback model.

Route 2: connect Ox Alpha directly to Claude Code through OpenRouter

OpenRouter exposes an Anthropic-compatible API surface specifically for Claude Code. This path needs an OpenRouter API key but no local proxy.

1. Create a scoped OpenRouter key

Create the key yourself in the official OpenRouter Keys dashboard. Give it a recognizable name and a small credit limit if the dashboard offers one. Never paste the real key into a chat, issue, screenshot, article, or committed file.

2. Test in one disposable terminal session

Use temporary shell variables first. Replace the placeholder locally:

export OPENROUTER_API_KEY="sk-or-your-key-here"
export ANTHROPIC_BASE_URL="https://openrouter.ai/api"
export ANTHROPIC_AUTH_TOKEN="$OPENROUTER_API_KEY"
export ANTHROPIC_API_KEY=""

export ANTHROPIC_DEFAULT_FABLE_MODEL="~stealth/ox-alpha"
export ANTHROPIC_DEFAULT_OPUS_MODEL="~stealth/ox-alpha"
export ANTHROPIC_DEFAULT_SONNET_MODEL="~stealth/ox-alpha"
export ANTHROPIC_DEFAULT_HAIKU_MODEL="~stealth/ox-alpha"
export CLAUDE_CODE_SUBAGENT_MODEL="~stealth/ox-alpha"

claude

The base URL is https://openrouter.ai/api without /v1. OpenRouter’s Claude Code guide says /v1 causes model-not-found errors. ANTHROPIC_API_KEY must be explicitly empty so Claude Code does not fall back to Anthropic authentication.

The leading ~ pins the exact OpenRouter model instead of allowing provider preference syntax to reinterpret the slug. Mapping every Claude Code role to the same preview model prevents a small background task or subagent from quietly switching to a paid model.

3. Clear an old Anthropic login if necessary

If Claude Code reports an authentication conflict or tries to find the model on Anthropic, run this inside Claude Code once:

/logout

Quit and relaunch claude. This clears a cached Claude login; it does not remove environment variables from your shell profile.

4. Verify the route before allowing edits

Inside Claude Code, run:

/status

You want to see ANTHROPIC_AUTH_TOKEN as the authentication source and https://openrouter.ai/api as the base URL. Then check /model, send one tiny read-only prompt, and confirm the OpenRouter Activity dashboard records stealth/ox-alpha at zero cost.

When the test is over, exit Claude Code and close that terminal. Because the variables were not added to .zshrc, .bashrc, or a project settings file, a fresh terminal returns to your normal provider.

Route 3: use CC Switch to run Zen’s free model inside Claude Code

This route keeps Claude Code as the harness while CC Switch translates its Anthropic Messages requests into Zen’s OpenAI-compatible chat format.

1. Protect the configuration you already have

CC Switch writes the active Claude configuration to ~/.claude/settings.json. Before adding anything, export a CC Switch backup or duplicate your current provider card. If you keep hand-written settings in that file, copy those values somewhere safe and check the resulting diff after the switch.

Do not import provider deep links from strangers. A provider deep link can contain an endpoint and API key; review every field yourself.

2. Add the Zen provider

In CC Switch:

1. Open the Claude app section—not Claude Desktop or Codex.
2. Click Add Provider and choose Custom Configuration.
3. Name it Ox Alpha via OpenCode Zen.
4. Enter your Zen API key in the API key field.
5. Set the endpoint root to https://opencode.ai/zen.
6. Set the default model to x-preview-f-free.
7. Expand Advanced Options and change the API format to OpenAI Chat Completions.
8. If role mapping is available, map Fable, Opus, Sonnet, and Haiku to x-preview-f-free so background tasks cannot fall through to a paid model.
9. Save the provider.

Do not paste the complete /v1/chat/completions URL into the normal endpoint field. CC Switch appends that path in its default prefix mode, so the root above resolves to Zen’s documented endpoint:

https://opencode.ai/zen/v1/chat/completions

3. Turn on the conversion route

Because Zen serves Ox Alpha through OpenAI Chat Completions rather than Anthropic Messages, the CC Switch proxy must stay running:

1. Go to Settings → Routing → Local Routing.
2. Turn on the Routing Master Switch.
3. Enable routing for Claude.
4. Return to the provider list and click Enable on Ox Alpha via OpenCode Zen.

CC Switch’s default local route is 127.0.0.1:15721. Keep CC Switch open for the whole session. Restart Claude Code if the current process does not pick up the switch.

4. Prove that the conversion works

Run /status in Claude Code, send the same small read-only prompt used in the direct test, and inspect CC Switch’s routing activity. Confirm three things before editing:

• the request counter increases;
• the upstream model is x-preview-f-free;
• the Zen usage record shows zero cost.

If you receive 401 or 403, recheck the Zen key. If you receive 404, make sure the endpoint is the https://opencode.ai/zen root and that Full URL mode is off. If tool calls fail, update CC Switch and Claude Code before blaming the model; this route depends on protocol translation.

To restore your normal setup, enable your previous provider card or an official-login provider, turn off Claude routing if you do not use it elsewhere, and verify /status again.

A useful first test—not a token bonfire

A million-token window invites people to throw an entire private repository at the model. That is the wrong first move. Context capacity is not a quality score, and a free preview is not a security review.

Choose a public repository or disposable project and freeze the starting commit. Give your normal model and Ox Alpha the same task, permissions, and tests. A good task has a real failure mode and a finish line:

Read the repository instructions first.
Diagnose the failing test without changing unrelated files.
Explain the cause in three sentences.
Implement the smallest fix.
Run the relevant test and the nearest broader test suite.
Show the changed files, test results, and any unverified boundary.

Record:

• accepted changed files;
• tests passed and failed;
• tool-call failures and retries;
• input, output, and cached tokens;
• wall time;
• human review and correction time;
• whether the model changed strategy after a failed approach.

The deal is useful if this evidence tells you whether Ox Alpha completes your kind of work more efficiently. “It used fewer tokens” is not a win if you spend an hour repairing the diff.

Privacy, limits, and other catches

The route changes the privacy promise

OpenCode Zen says the Ox Alpha provider follows a zero-retention policy and does not use data for training. OpenRouter says its anonymous provider retains prompts and completions but does not use them for training. OpenRouter itself says its own prompt logging is opt-in, but that does not cancel the upstream provider’s retention policy.

Do not send either route secrets, wallet keys, customer data, private contracts, production .env files, unreleased strategy, or a repository you are not authorized to share. For OpenRouter, assume the provider will keep the content for an unspecified period.

Free OpenRouter requests are limited

OpenRouter’s FAQ says accounts that have not purchased at least $10 of credits normally receive 50 free-model requests per day in total. Accounts that have purchased at least $10 receive 1,000 per day. Those are request limits, not a promise of fast or uninterrupted service. A coding agent can consume many requests during one task.

Buying credits raises the free-model request cap; it does not make Ox Alpha permanent or private. Set a key budget and confirm the selected model so a fallback cannot consume paid credits unexpectedly.

Zen had billing controls even while the model was free

Zen asked for billing details and documented an auto-reload feature. Although the Ox Alpha route was free during the preview, other models in the same account were not. That remains the useful lesson: tune auto-reload, add a monthly limit, and verify the selected model before a long session.

The model can change behind the same name

The operator was anonymous during the test window and did not publish a checkpoint history. OpenRouter’s later identification resolves the lab question, but not every routing or configuration detail from the preview. Improved or different output on another day could still come from a backend swap, system-prompt change, routing change, provider load, or sampling variance. Save the date, gateway, model ID, harness version, repository commit, and acceptance test with every result.

Verdict

Ox Alpha was exactly the sort of free preview worth testing: long context, tool support, and enough early evidence to justify one controlled coding task. Its abrupt end also shows why temporary pricing is not evidence of a permanent bargain or production-safe data handling.

Do not configure the former free routes from this archive. If you evaluate the revealed GLM-5.3-Flash model now, start from its current official provider listing and terms, then reuse the same bounded comparison workflow.

For any replacement route, keep the first job public, bounded, reproducible, and reviewed. The finish line is not “used a million tokens.” It is a tested diff you would accept.

Sources

• OpenRouter: retrospective Ox Alpha identification and former model details
• OpenRouter: official Claude Code integration guide
• OpenRouter: free-model request limits
• OpenRouter: data collection and provider-logging distinction
• OpenCode Zen: current setup, model table, billing controls, and privacy policy
• CC Switch: add a custom provider and select an API format
• CC Switch: switch providers and understand which Claude Code file changes
• OpenCode launch announcement mirror: “free for the next week” from August 20

Put this to work

Separate the model, gateway, coding harness, price, limits, and data policy instead of treating 'free Ox Alpha' as one product.

Try

Run one bounded task on a public or disposable repository, first through your normal model and then through Ox Alpha.

Prove it worked

Compare accepted files, passing tests, retries, wall time, token use, and human correction time on the same commit.

Where it can pay

A repeatable model-routing and evaluation workflow helps freelancers protect margin when temporary free tiers disappear.

Keep in view

• Ox Alpha was a short coding and reasoning preview that OpenRouter later identified as Z.ai GLM-5.3-Flash.
• OpenRouter and OpenCode Zen offered different zero-cost routes, rate limits, billing controls, and retention terms during the preview.
• The former model IDs are preserved below for editorial history, not as a current setup recommendation.
• No primary page published an exact cutoff time, so the old inferred expiry has been removed from the deals inventory.

Learn the workflow: the supervised Claude Code workflow →