Ghost Schema · On-Prem Agentic Database · Proudly the slowest and the most expensive query engine · Most accurate

Deep research on every query.

The idea

User query
    │
    ▼
Claude Code (Architect) — one sandboxed instance per query
    Inspects schema · writes inference script · self-corrects
    │
    ▼
Gemini 2.5 Flash (Workers) — one call per row, fully parallel
    Classifies each row · writes results to jit_columns cache
    │
    ▼
Final SQL · answer streamed back to browser

No prompt engineering. No templates. No retry code written by hand. Claude Code handles schema discovery, script authoring, and error recovery on its own.

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Stack

Layer	Technology
Architect	Claude Code CLI (claude -p) in a temp-dir sandbox
Workers	Gemini 2.5 Flash — parallel row classification
Store	SQLite (one file per project) + EBS in production
API	FastAPI + SSE streaming
UI	Vanilla HTML/JS, no build step

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Quickstart (local)

git clone https://github.com/MayankChaturvedi/ghost_schema
cd ghost_schema
cp .env.example .env   # add your GEMINI_API_KEY
pip install -r requirements.txt
uvicorn main:app --port 8000 --reload

Open http://localhost:8000 — the UI will prompt for your API keys on first launch.

You only need a Gemini key locally. Claude Code uses your existing OAuth session automatically (run claude once to log in).

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One-click AWS deploy

export ANTHROPIC_API_KEY=sk-ant-...
export GEMINI_API_KEY=AIza...
export KEY_NAME=my-ec2-keypair   # optional, for SSH
./deploy.sh

Provisions a t3.medium EC2 instance + 20 GB EBS volume (persists across restarts). App is live on port 8000 in ~2 minutes.

AWS prerequisites:

• aws CLI installed and configured (aws configure)
• IAM permissions: EC2 (RunInstances, CreateSecurityGroup, AuthorizeSecurityGroupIngress, DescribeImages, DescribeInstances)

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How JIT columns work

-- Cached in jit_columns after first query
table_name  entity_id  column_name          value
companies   1          sells_to_healthcare  yes
companies   2          sells_to_healthcare  no
companies   3          sells_to_healthcare  yes
...

The second time you ask "how many companies sell to healthcare?" — no Gemini calls, instant SQL.

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API keys

Key	Used by	Where to get
Anthropic	Claude Code Architect subprocess	console.anthropic.com
Gemini	Inference workers	aistudio.google.com/apikey

Locally: Anthropic key is optional — Claude Code reuses your OAuth session. Docker/AWS: both keys required, injected via environment variables.