jack is a private knowledge retrieval API. You give it your documents — it gives your application the ability to answer questions about them in plain English, with exact citations, in under 2 seconds.
What jack is
jack is infrastructure. Your users never interact with jack directly. You call jack from your backend, and embed the answers wherever your product needs them — a support chat, a field assistant, a compliance tool, an internal wiki.
Under the hood, jack runs a hybrid retrieval pipeline — vector search fused with a knowledge graph — so answers are accurate across both semantic meaning and explicit relationships in your documents. Every answer returns the exact source it was pulled from.
What you can build
→Smart search for an internal knowledge base
→Document Q&A inside your SaaS product
→A field assistant that answers from uploaded records
→A compliance tool that queries contracts and policy documents
→Any feature where users need answers from a body of documents
How it works
01
Ingest
Send your documents to jack — text, files, or URLs. Jack chunks, embeds, and builds a knowledge graph. Status goes to ready in under 60 seconds.
02
Query
POST a question. Jack runs hybrid retrieval (vector + graph), synthesises the answer, and returns it with citations in the response body.
03
Ship it
Render the answer in your product. Use the blocking endpoint or stream tokens in real time. The source citation is always there.
Base URL
base url
https://api.usejack.io
Quick example
Ingest a document and ask your first question in four lines:
python
import httpx
# 1. Ingest
httpx.post(
"https://api.usejack.io/v1/ingest",
headers={"Authorization": "Bearer jack_xxxxxxxx"},
json={"documents": [{"text": "...", "metadata": {"type": "policy"}}]}
)
# 2. Query
resp = httpx.post(
"https://api.usejack.io/v1/query",
headers={"Authorization": "Bearer jack_xxxxxxxx"},
json={"question": "What is the remote work policy?"},
timeout=30
)
print(resp.json()["answer"])
# "Employees may work remotely up to 3 days per week with manager approval."
Every API key is scoped to your organisation. All data is isolated at the database level — no cross-tenant queries are possible architecturally.
API status
Check GET /healthz for liveness. No authentication required. Returns { "status": "ok" } when the API is up.