Write code
Implement functions, endpoints and features in the language you already use.
FREE AI CODING
INTELLIGENCE.
Tessen ZERO Alpha is Tessen’s free AI coding intelligence experience for developers. It is built for real software-development work — writing code, debugging, refactoring, testing and understanding codebases.
- Product
- Tessen ZERO Alpha
- Made by
- Tessen Inc.
- Category
- AI coding intelligence
- Audience
- Developers
- Status
- Alpha
- Price
- Free during Alpha
- Paid fallback
- No
- Primary use
- Software development
INTELLIGENCE,
AT NO COST.
ZERO Alpha is Tessen’s free AI coding intelligence experience for developers. It is an Alpha product: free while it is in Alpha, and Alpha behaviour can change.
It is not a paid tier and it does not require a subscription. When ZERO cannot serve a request, it is refused with a reason — it is never quietly turned into paid inference.
WORK, NOT
DEMOS.
Build features
Take a requirement from description to working code.
Debug problems
Find why something fails and fix it, rather than guessing at the cause.
Refactor code
Restructure existing code without changing what it does.
Write tests
Produce tests that cover the behaviour you actually changed.
Understand codebases
Read unfamiliar repositories and explain how they fit together.
YOUR TOOLS.
ZERO INTELLIGENCE.
Bring Tessen intelligence into your OpenCode workflow. The Tessen CLI adds a Tessen provider to your OpenCode configuration; you select the ZERO model inside OpenCode and work as you normally would.
You authenticate with your Tessen account. You never handle a provider credential, and Tessen decides which routes ZERO may use — OpenCode cannot choose an arbitrary model into ZERO.
Model reference inside OpenCode: tessen/project-zero
NO CARD.
NO BILL.
ZERO Alpha is free for developers during Alpha. There is nothing to buy and nothing to subscribe to.
Capacity comes from a shared Zero Pool that refills on a daily cycle. It is not unlimited, and we would rather say so than promise a capacity we cannot guarantee.
IT REFUSES.
IT DOESN’T BILL.
Most “free” tiers quietly upgrade a request to a paid model when their own capacity runs out. ZERO does not. If ZERO cannot serve a request, the request is refused with a reason.
That is the difference between being free and being free-and-then-charged. A ZERO request either runs on ZERO, or it does not run at all.
DEVELOPERS.
INTELLIGENCE. SOFTWARE.
Tessen is building a path from developers, through intelligence, to software that gets written. ZERO Alpha is the free entry point into that ecosystem: the place where a developer gets useful work done before deciding anything else about Tessen.
It is an Alpha product and it will change. What it will not do is quietly start costing money.
USE THE INTELLIGENCE.
JOIN THE NETWORK.
Coming next — not available today.
Tessen Node is Tessen’s intended network layer. The direction is a simple one: more Nodes contribute more distributed capacity, which means more intelligence available, which means more developers building.
The intended end state is that a developer with a spare computer or server can connect it and contribute capacity to the network ZERO runs on. Node is not live today and supplies no ZERO capacity yet — this section describes where Tessen is going, not what you can use now.
YOUR NEXT
MISSION.
Sign in
Use your Tessen account — Google, email, or GitHub where it is offered. Your developer identity is your Tessen identity; there is no separate developer account.
Install the Tessen CLI
One command. It verifies the download's checksum and installs into its own folder — no sudo. Requires Node.js 20 or newer, on macOS, Linux or WSL.
curl -fsSL https://github.com/TessenLab/zero/releases/latest/download/install.sh | shAuthorize this machine
The CLI shows a short code and opens the Tessen approval page in your browser. Approve it while signed in; the CLI receives a credential bound to your identity. You never paste a key.
tessen auth:loginCheck your access
Shows whether your account has Project Zero access and when today's window resets.
tessen zeroConnect OpenCode
Adds the Tessen provider to OpenCode and hands OpenCode the credential from the previous step. The configuration file never contains a secret.
tessen opencodeBuild
Run OpenCode on Project Zero by selecting tessen/project-zero.
opencode --model tessen/project-zero
QUESTIONS,
ANSWERED.
What is Tessen ZERO Alpha?
Tessen ZERO Alpha is Tessen's free AI coding intelligence experience for developers, used for real software-development work such as writing code, debugging, refactoring, testing and understanding codebases.
Is Tessen ZERO free?
Yes. ZERO Alpha is free during the Alpha period. It is not a paid tier and it does not require a subscription.
What can I use ZERO for?
Software development: writing code, debugging problems, refactoring, writing tests, understanding codebases and building features.
Who is ZERO for?
Developers, software engineers and anyone working with code.
Does ZERO fall back to paid models?
No. If ZERO cannot serve a request it is refused with a reason. It is never quietly turned into paid inference.
What is Tessen Node?
Tessen Node is Tessen's intended network layer for additional distributed capacity. It is a direction, not a shipped feature: it supplies no ZERO capacity today.
Is ZERO Alpha production-ready?
ZERO Alpha is an Alpha product. It is free during Alpha, Alpha behaviour can change, and Tessen Node is not yet live as a capacity source.