Hy3 can help an agent read a signed-in page and prepare a form, but Hy3 does not control a browser on its own. Pair it with an agent client that can call a local browser tool, serve Hy3 through a compatible endpoint, then use Tabbit CLI to let that client work in Tabbit Browser. For the example below, the agent copies visible fields into a test form and stops before submission. The user reviews the values in the browser.
A Reddit user working through a local Hy3 setup wrote, “I had to pick a quant.” (original discussion) That is a useful reminder: model weights and runtime choices come before any browser integration. This is a practical model-and-browser setup guide, not a claim that Hy3 has been tested with every agent client. Tencent's current Hy3 card documents local inference with vLLM and SGLang. Confirm that your chosen client accepts the endpoint and that its tool-call format works before connecting a real site. A useful place to start is the Tabbit CLI complete guide.
Key takeaways
Hy3 is Tencent's July 2026 production release. It is distinct from Hy3-preview, with a different license.
The official model card documents local vLLM and SGLang serving. It does not establish that every hosted API or agent client offers Hy3.
The agent client selects Hy3; Tabbit CLI provides a route to browser tabs. Website sign-in belongs to the Tabbit Browser profile.
Give the agent a narrow read-and-fill task, request a structured result, and stop before any irreversible action.
Keep the browser visible and verify each field against its source before submitting anything.
Hy3 browser use at a glance
| Part | What it does | Check before the task |
|---|---|---|
| Hy3 model | Interprets the instruction and proposes tool calls | Confirm the exact tencent/Hy3 model ID and license |
| Inference server | Runs the weights and exposes an endpoint | Follow the model card for the selected runtime; check resources and tool-call support |
| Agent client | Sends prompts to Hy3 and executes approved tools | Verify it can use your endpoint and a local browser connector |
| Tabbit CLI | Connects the client to Tabbit Browser tabs | Install and check the CLI using the setup walkthrough |
| Website session | Supplies the already authenticated page | Sign in to the site in the same Tabbit Browser environment first |
| Human review | Confirms the copied data and decides whether to submit | Leave submit, save, and send actions for a person |
Set up the model and browser separately
Tencent's official Hy3 release note describes the production release and Apache 2.0 licensing. The Hy3 Hugging Face card provides weights and documents a vLLM server with an OpenAI-compatible chat-completions endpoint; it also shows an SGLang option. These are serving instructions, not a promise that a public hosted provider has the exact model available today. For a hosted endpoint, check the provider's live model list, region, terms, and tool-call behavior before you configure the client.
There are four separate checks:
Model: Select
tencent/Hy3, nottencent/Hy3-preview. The production card lists Apache-2.0; the preview card lists Tencent Hy Community License. Read the license files for your planned use.Endpoint: Run the model in a supported runtime or choose a hosted endpoint only after confirming the exact model ID is live there. The official local recipe is the most directly documented path.
Client: Configure an agent client that lets you set the model endpoint and supports local tools. A model's tool-use training does not install tools into the client.
Browser and login: Install Tabbit Browser and Tabbit CLI. Follow the CLI guide for your client, then sign in to the target website inside the Tabbit environment the CLI will use.
The client may discover the Tabbit skill through /tabbit, a /skills command, or its own configured skill mechanism. Pi uses /skill:tabbit. Skill discovery only makes the instructions available; it does not prove that the CLI launcher is installed, that the model endpoint is reachable, or that the site is signed in. Check each separately. The MCP versus CLI guide explains when a local CLI connection fits.
A safe first task: copy fields, then pause
Use a page and form you are allowed to access. For the first run, use a test record or staging form. Avoid financial, medical, or identity data. Keep the browser window visible so you can compare the source and destination.
Tell the agent which values to copy and what it must not do. Ask it to return a compact table with the source label, copied value, and verification status. Do not include hidden page data or ask it to infer missing fields.
Open the signed-in support page in the current Tabbit Browser task tab.
Find the record with visible reference ID TEST-104. Copy only its visible
customer name, issue category, and public record URL into the test form.
Do not click Save, Submit, Send, or any control that changes the record.
If a field is missing or ambiguous, leave it blank and explain why.
Return a table with: source label, copied value, destination field, and
confidence note. Stop with the form open for my review.For a real support site, replace the test ID with an authorized record identifier. Do not put customer data in a prompt that is logged by an unrelated provider. This example is a test fixture workflow, not a verified live integration.
Compare the returned table to the visible source page. Then inspect the filled form itself. Correct mismatches manually, and only submit after checking the site's intended recipient and effect. A first-task checklist is useful when you are still learning what the browser agent can see. If the task involves copying a table, see the guide to moving browser data into a CSV.
What to do when a tool call fails
A model can emit a plausible tool call that the client rejects. If a click does nothing, check the client log for the actual tool name and arguments, then confirm the browser connector is attached to the current task tab. Do not let the agent retry a submit action blindly. The browser agent click troubleshooting guide covers selector and page-state checks. For large pages, ask for only the few labels you need; the guide to reducing browser-agent token use explains how to limit page context.
In the same Reddit discussion, u/colin_colout called Hy3 “an extremely solid and reliable model for tool calling” in the same Reddit discussion, while distinguishing that opinion from coding performance. Treat this as one user’s view, not a browser-agent benchmark. Another participant described a GGUF architecture-label mismatch with a llama.cpp port. That is a specific community report, not an official installation requirement or a general model failure. Keep your runtime version and model card nearby when diagnosing a local issue.
Use Tabbit Browser as the visible review point
If the task needs an existing website login, Tabbit Browser provides the browser environment and Tabbit CLI lets a compatible local agent work with its tabs. Sign in once in the target Tabbit environment, then launch the agent task through the CLI. The agent's own task tab is separate from the tabs you use to keep working. You can leave research open in one tab, ask the agent to prepare a draft in another, and inspect its result in the browser before deciding what happens next.
The sign-in is reusable only within the connected Tabbit environment. It does not transfer to a cloud agent running elsewhere. A remote runner needs a separately supported local handoff. The model client remains responsible for Hy3 selection and inference; the browser connector remains responsible for browser actions. Review the agent connection guide if either boundary is unclear.
Decision checklist
| Situation | Recommended next step | Why |
|---|---|---|
| You already have a local Hy3 endpoint and a client with local tools | Test a read-only page, then a staging form | Verifies model, client, and browser connector independently |
| You want a hosted Hy3 API | Check the provider's live model ID, terms, and tool-call format first | Tencent's availability announcement is not proof of current provider access |
| Your client cannot call a local browser tool | Choose a client with a documented local connector or use a human handoff | Hy3 itself cannot bridge the client to your logged-in session |
| You need to update a consequential record | Let the agent prepare the values and stop | A person should verify the effect and submit |
For a real run, name the draft clearly, such as Support intake / TEST-104 / review, and keep the page open at the review checkpoint. If your agent client is Codex, the Codex and Tabbit CLI setup covers that client-side path. Start with a harmless test form, confirm every value, and only then decide whether to use the workflow on production data.
FAQ
Can Hy3 open a signed-in website by itself?
No. Hy3 is a language model, so an agent client must connect it to a browser tool. The client, model endpoint, browser connector, and website login are separate parts.
Is Hy3 the same model as Hy3-preview?
No. Tencent released Hy3 as the production model after Hy3-preview. The official Hy3 card uses Apache 2.0, while the preview used Tencent Hy Community License terms.
Can I run Hy3 locally?
Tencent publishes Hy3 weights and documents serving it with vLLM or SGLang. The full repository is large, so check current hardware and serving requirements before downloading.
Does Tabbit CLI choose or host Hy3?
No. Tabbit CLI connects an agent to browser tabs in Tabbit Browser. You choose a model endpoint in an agent client that supports it.
How do I keep an agent from submitting a form?
Tell it to stop before submission, omit submit controls from its allowed actions where possible, and check the completed fields in the browser yourself. Do not rely on a prompt as the only safeguard.
Does the browser task inherit my website login?
Tabbit CLI can work with the signed-in Tabbit Browser environment it connects to. The website must already be logged in there; a separate agent client or remote runner does not gain that session automatically.