Ollama REST API

Overview

The Ollama REST API provides direct HTTP access to all Ollama functionality. Use the requests library for maximum control over API interactions.

Default Endpoint: http://localhost:11434 (or http://ollama:11434 in containers)

Quick Reference

Setup

import os
import requests
import json

OLLAMA_HOST = os.getenv("OLLAMA_HOST", "http://localhost:11434")

List Models

response = requests.get(f"{OLLAMA_HOST}/api/tags")
models = response.json()

for model in models.get("models", []):
    size_gb = model.get("size", 0) / (1024**3)
    print(f"  - {model['name']} ({size_gb:.2f} GB)")

Show Model Details

response = requests.post(
    f"{OLLAMA_HOST}/api/show",
    json={"model": "llama3.2:latest"}
)
model_info = response.json()

details = model_info.get("details", {})
print(f"Family: {details.get('family', 'N/A')}")
print(f"Parameter Size: {details.get('parameter_size', 'N/A')}")
print(f"Quantization: {details.get('quantization_level', 'N/A')}")

List Running Models

response = requests.get(f"{OLLAMA_HOST}/api/ps")
running = response.json()

for model in running.get("models", []):
    name = model.get("name", "Unknown")
    size = model.get("size", 0) / (1024**3)
    vram = model.get("size_vram", 0) / (1024**3)
    print(f"  - {name}: {size:.2f} GB (VRAM: {vram:.2f} GB)")

Generate Text

Non-Streaming

response = requests.post(
    f"{OLLAMA_HOST}/api/generate",
    json={
        "model": "llama3.2:latest",
        "prompt": "Why is the sky blue?",
        "stream": False
    }
)
result = response.json()
print(result["response"])

Streaming

response = requests.post(
    f"{OLLAMA_HOST}/api/generate",
    json={
        "model": "llama3.2:latest",
        "prompt": "Count from 1 to 5.",
        "stream": True
    },
    stream=True
)

for line in response.iter_lines():
    if line:
        chunk = json.loads(line)
        print(chunk.get("response", ""), end="", flush=True)
        if chunk.get("done"):
            break

Chat Completion

response = requests.post(
    f"{OLLAMA_HOST}/api/chat",
    json={
        "model": "llama3.2:latest",
        "messages": [
            {"role": "system", "content": "You are a helpful assistant."},
            {"role": "user", "content": "What is Python?"}
        ],
        "stream": False
    }
)
result = response.json()
print(result["message"]["content"])

Generate Embeddings

response = requests.post(
    f"{OLLAMA_HOST}/api/embed",
    json={
        "model": "llama3.2:latest",
        "input": "Ollama makes running LLMs locally easy."
    }
)
result = response.json()
embeddings = result.get("embeddings", [[]])[0]
print(f"Dimensions: {len(embeddings)}")

Copy Model

response = requests.post(
    f"{OLLAMA_HOST}/api/copy",
    json={
        "source": "llama3.2:latest",
        "destination": "llama3.2-backup:latest"
    }
)
if response.status_code == 200:
    print("Copy successful!")

Delete Model

response = requests.delete(
    f"{OLLAMA_HOST}/api/delete",
    json={"model": "llama3.2-backup:latest"}
)
if response.status_code == 200:
    print("Delete successful!")

Error Handling

try:
    response = requests.post(
        f"{OLLAMA_HOST}/api/generate",
        json={"model": "nonexistent", "prompt": "Hello"},
        timeout=30
    )
    if response.status_code != 200:
        print(f"Error: {response.status_code} - {response.text}")
    else:
        result = response.json()
        if "error" in result:
            print(f"API Error: {result['error']}")
except requests.exceptions.ConnectionError:
    print("Cannot connect to Ollama. Ensure server is running at OLLAMA_HOST")
except requests.exceptions.Timeout:
    print("Request timed out")

Connection Health Check

def check_ollama_health(model="llama3.2:latest"):
    """Check if Ollama server is running and model is available."""
    try:
        response = requests.get(f"{OLLAMA_HOST}/api/tags", timeout=5)
        if response.status_code == 200:
            models = response.json()
            model_names = [m.get("name", "") for m in models.get("models", [])]
            return True, model in model_names
        return False, False
    except requests.exceptions.RequestException:
        return False, False

server_ok, model_ok = check_ollama_health()

Response Metrics

The generate endpoint returns useful metrics:

result = response.json()
print(f"Prompt eval count: {result.get('prompt_eval_count', 'N/A')}")
print(f"Prompt eval duration: {result.get('prompt_eval_duration', 0) / 1e9:.3f}s")
print(f"Eval count (tokens): {result.get('eval_count', 'N/A')}")
print(f"Eval duration: {result.get('eval_duration', 0) / 1e9:.3f}s")
print(f"Total duration: {result.get('total_duration', 0) / 1e9:.3f}s")

if result.get('eval_count') and result.get('eval_duration'):
    tokens_per_sec = result['eval_count'] / (result['eval_duration'] / 1e9)
    print(f"Tokens/second: {tokens_per_sec:.1f}")

When to Use This Skill

Use when:

• You need direct control over HTTP requests
• Debugging API interactions
• Building custom integrations
• Working with streaming responses
• Checking raw API responses

Cross-References

• bazzite-ai-ollama:python - Higher-level Python library
• bazzite-ai-ollama:openai - OpenAI-compatible interface