This post goes over how to set up OpenCode with Ollama.

Install

Ollama:

brew install ollama

OpenCode:

brew install opencode

Ollama

Start the server in a separate terminal:

ollama serve

Install gemma4:

ollama pull gemma4

Confirm it’s downloaded:

ollama ls gemma4

You should see:

NAME             ID              SIZE      MODIFIED
gemma4:latest    c6eb396dbd59    9.6 GB    5 seconds ago

Check the model’s context length:

ollama show gemma4

You should see:

  Model
    architecture        gemma4
    parameters          8.0B
    context length      131072
    embedding length    2560
    quantization        Q4_K_M
    requires            0.20.0

Restart the server with the context length (to maximize memory):

OLLAMA_CONTEXT_LENGTH=131072 ollama serve

Check the performance of the model:

ollama run gemma4 "ping" && ollama ps

OpenCode

Launch opencode with gemma4:

ollama launch opencode --model gemma4