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self hosted ai for decisions

github-actions[bot] edited this page Oct 1, 2026 · 6 revisions

Self-hosted AI for decisions

Self-hosting a decision model means running three things you control: a model file, a runtime that executes it, and a server on a port that your application calls. For jevos that is the model folder from jevos-v2-openvino-int8.zip, the prebuilt jev binary for your platform with OpenVINO's libraries beside it, and jev serve listening on 127.0.0.1:8017. There is no GPU to provision and no account to open. What you take on instead is the work a hosted API did quietly: knowing which model answered, updating it deliberately, keeping the port private, and noticing when it is down.

The non-obvious part is that the hard problem of self-hosting a large chat model, finding hardware that can run it, mostly disappears for a small decision model. What remains is ordinary service operations, and the one habit worth building early is identifying the model by its file hash rather than by its name.

This page is what you install, how to run it as a service, how to know which model is answering, how to update it, what stays your job, and when a hosted API is still the better choice.

What do you actually install?

Three pieces, all from the release page, with SHA256SUMS.txt next to them:

  1. The jev folder, from jev-linux-x64.tar.gz, jev-windows-x64.zip or jev-macos-arm64.tar.gz: the binary, OpenVINO's libraries and the licenses. Nothing is compiled, and there is no Python to install.
  2. The model, jevos-v2-openvino-int8.zip, unpacked into the jev folder as jev/model.
  3. The server, started from the jev folder (.\jev.exe serve on Windows):
./jev serve

--threads defaults to all logical CPUs; set it lower if other heavy programs run on the same machine. --host and --port change where it listens, and --model-dir points at a model folder elsewhere. If you do not need a server at all, jev decide answers one request file and exits, which suits batch jobs; see batch decisions from files with jev decide.

Running it as a service

The server is one process holding one model. Treat it like any other internal HTTP dependency.

  • Readiness. GET /health returns {"status": "ready", ...} once the model is loaded. Point your service manager's health check, or your load balancer, at it, and do not send traffic before it answers.
  • Timing. Every successful response carries a Server-Timing header with the inference time and the total. Log it next to your own wall-clock measurement, so you can tell the model's cost from your network's.
  • Capacity. The measured figures come from one laptop, an Intel Core Ultra 7 255H with 16 threads: 26 ms for a short request and 112 ms for a 191-token one read from scratch, and 8.7 requests per second from one client, 10.1 from eight. Your hardware and inputs will differ; measure them as described on measuring LLM latency.
  • Restarts. Loading takes time and memory. A supervisor that restarts the process on crash and waits for /health before routing to it is enough for most setups.

How do you know which model is answering?

By hash. Answers name the served model, jevos-v2, but a name is not an identity. Check the release archives you unpack against SHA256SUMS.txt, and record those hashes with every deployment: two servers unpacked from the same archives run the same binary on the same model.

This matters more than it seems. A file renamed on disk, a copy that did not finish, or a different quantization behind the same file name all look identical in a config file and give different answers. Recording the hashes in every decision log turns "which model made this decision in March?" into a lookup; logging LLM decisions for audit shows what else to keep with it.

Updating deliberately

Nothing updates itself. A new model means a new model folder, and a new runtime means a new jev release. That is the property you want from a decision service, where silent changes of behaviour are the expensive kind. A reasonable update routine:

  1. Download the new file and check it against SHA256SUMS.txt.
  2. Run your own labelled test set against old and new side by side, per kind of question; a hundred real cases is a useful start, as on building a yes/no test set.
  3. Re-check your thresholds, because a new model's probabilities are not the old model's.
  4. Switch, and keep the old file until the logs show the new one behaves.

The runtime works the same way. OpenVINO's libraries ship inside the jev folder, so the runtime changes only when you unpack a new release, and its hash is part of what you record; the reasons for pinning a runtime are on using llama.cpp prebuilt binaries.

What stays your job

Self-hosting moves the model onto your machine and the responsibilities with it.

  • Access. The server listens on 127.0.0.1 by default, so only the same machine can reach it. If you bind it to another interface, set JEV_API_KEY when you start it: every call except /health then needs Authorization: Bearer <key>, and a missing or wrong key gets a 401. The server does not terminate TLS; put a reverse proxy in front if the traffic leaves the host. Details on securing a local LLM server with an API key.
  • Data. The text never leaves the machine, but your application, your proxy and your logs can still keep it. Self-hosting does not decide retention for you.
  • Quality. A hosted provider may improve its model under you; a self-hosted file does not change. That is stability, and it is also the reason to re-measure when your inputs drift.

When a hosted API is still the better choice

Being straight about the limit: jevos answers yes/no and multiple-choice questions in English and, early, scores (54% on held-out score questions). On 2,000 yes/no questions about business policies none of the models was tuned on, the hosted Jev was right 0.927 of the time against 0.810 for jevos. If the decision needs that accuracy, other languages, or scores, the hosted model is the right tool, and because the wire format is the same, moving between the two is a base URL change. The broader trade-off is on local vs hosted LLM decisions.

Short answers to the questions that lead here

What does self-hosted AI mean? Running the model on hardware you control instead of calling someone else's API. For a decision model that is a file, a runtime and a local server.

Do I need a GPU to self-host? Not for jevos. jev runs on the CPU only: x86-64 with AVX2, or Apple silicon.

How do I update a self-hosted model safely? Verify the new file's hash, test it against your own labelled cases, re-check thresholds, then switch, keeping the old file.

Can other machines call it? Only if you bind it to a reachable interface. Set JEV_API_KEY first, and add a reverse proxy for TLS.

Is it free? The code is MIT and the model file is a download; the cost is your hardware and your time running it.

See also: offline AI for decisions, on-premise LLM for business decisions and ask a local LLM a yes/no question.

Sources

  • Commands, options, endpoints and release files: the jev README.
  • Latency, throughput and the 2,000-question comparison: our measurements, reported in the README.

From the notes of jev, a decision server that is one binary beside one model folder, both known by the hashes you record.

Guides

Measurements

Comparisons

Speed

Probability and thresholds

Question design

Use cases

Evaluation

Agents and routing

Integrations

Local and private AI

llama.cpp and GGUF

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