Ollama can build models automatically by reading the instructions from a Modelfile. A Modelfile is a text document that represents the complete configuration of the Model. You can see that a Modelfile is very similar to a Dockerfile.
## Format
Here is the format of the Modelfile:
```modelfile
# comment
INSTRUCTION arguments
```
Nothing in the file is case-sensitive. However, the convention is for instructions to be uppercase to make it easier to distinguish from the arguments.
A Modelfile can include instructions in any order. But the convention is to start the Modelfile with the FROM instruction.
Although the example above shows a comment starting with a hash character, any instruction that is not recognized is seen as a comment.
## FROM
```modelfile
FROM <image>[:<tag>]
```
This defines the base model to be used. An image can be a known image on the Ollama Hub, or a fully-qualified path to a model file on your system
Some models need to be distributed with a license agreement. For example, the distribution clause for the Llama2 license requires including the license with the model.
| temperature | The temperature of the model. Higher temperatures result in more creativity in the response | float | 0 - 1 |
| TopK | | int | |
| TopP | | float | |
| TFSZ | | float | |
| TypicalP | | float | |
| Mirostat | | int | |
| MirostatTau | | float | |
| MirostatEta | | float | |
| NumThread | | int | |
## PROMPT
Prompt is a multiline instruction that defines the prompt to be used when the model is run. Typically there are 3-4 components to a prompt: System, context, user, and response.
```modelfile
PROMPT """
{{- if not .Context }}
### System:
You are a content marketer who needs to come up with a short but succinct tweet. Make sure to include the appropriate hashtags and links. Sometimes when appropriate, describe a meme that can be includes as well. All answers should be in the form of a tweet which has a max size of 280 characters. Every instruction will be the topic to create a tweet about.
