Jan vs Ollama

Jan

Apache-2.0, with installers for macOS, Windows and Linux plus Flathub and the Microsoft Store. No release since 0.8.4 on 23 July 2026, while a security fix waits on main.

Ollama

An OpenAPI 3.1 file for the 15 native operations and llms.txt with 68 links to Markdown pages. No credential on the local API, and any caller that reaches it can pull, push, create and delete models.

Jan

1. Ask the owner to start the server (Settings, Local API Server) or run jan serve. Nothing listens until then
2. Call http://127.0.0.1:1337/v1 for the app and localhost:6767/v1 for jan serve. The ports differ
3. Read /openapi.json from the running server, not the spec on the docs site, which describes the retired Cortex API
4. Branch on the status code. Error bodies are plain text
5. Keep the bind at 127.0.0.1 on 0.8.4. Trusted Hosts is ignored on 0.0.0.0 until the next release

Ollama

1. Send "stream": false for one JSON body. The native routes stream NDJSON by default
2. Set OLLAMA_CONTEXT_LENGTH=64000 or options.num_ctx before agent work. The default is 4k below 24 GiB of VRAM
3. Back off on a 503. It means the queue (512 by default) is full
4. Put an authenticating proxy in front before binding past 127.0.0.1. The server checks no credential
5. Expect model names with a cloud tag to run on Ollama's servers. They need ollama signin and fail with OLLAMA_NO_CLOUD=1