Install ONTO. Run an agent. Read the full reference.
This page is the on-ramp. The full reference — concepts, SDK, server, models — lives at the canonical docs site, linked below.
Get started in 60 seconds.
No account needed. ONTO defaults to free open-weight models on Ollama Cloud, so you can run your first agent with a single pip install and an env var.
- No API key relationship needed to start — defaults to free open-weight models.
- Same primitives in Python, TypeScript, Rust, and over HTTP.
- On-prem path uses Sled or Postgres + pgvector. No data has to leave your network.
pip install onto-coreThen export OLLAMA_API_KEY to use the free open-weight default. Or set ANTHROPIC_API_KEY / OPENAI_API_KEY to swap providers.
Quickstart — Python
Three lines after install. Defaults to a free open-weight model, so no API key relationship is needed.
from onto import Onto, Models, BuiltinTools
# 1. Initialize. Defaults to Ollama Cloud (free open-weight model).
onto = Onto(
model=Models.GPT_OSS_20B,
builtin_tools=BuiltinTools.STANDARD,
)
# 2. Run with consent scopes.
result = onto.run_sync(
"Hi, I'm Alice. UTC, mornings. Plan me a 3-day trip to Lyon.",
user_id="alice",
consent_scopes=["memory:write"],
extract=True, # auto-extract typed facts
)
# 3. Inspect what the agent learned.
for ea in result.extracted_assertions:
print(f"{ea.level:8} {ea.subject}.{ea.predicate} = {ea.object!r}")
# → profile alice.timezone = "UTC"
# profile alice.prefers = "mornings"
# session alice.location = "Lyon"Read the full documentation.
ONTO's canonical docs live at onto-framework.github.io. Browse by topic below or read the project README.
Concepts
Plan Mode, UPO + SMO, extraction, Policy Guard, provider model.
SDK reference
Onto class, run, streaming, tasks, memory, MCP, hooks, eval.
HTTP server
Deployment, auth, K8s + Helm, Postgres tuning, REST reference.
Models & providers
Ollama Cloud (default), OpenAI, Anthropic, custom providers.
Star the repo, file an issue, send a PR.
ONTO is built in the open. Pre-1.0 we will break the SDK when it makes the SDK better — tracked in the public roadmap.