# Factordb

> Auth/lab ref: public factorization database and simple JSON API for checking whether integers are prime, composite, or already factored.

- Skill: `aeondave/factordb` (Agent Skill)
- Install (CLI): `npx skillmds@latest add aeondave/factordb`
- Raw SKILL.md: https://api.skillmd.com/api/skills/aeondave/factordb/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: AeonDave (https://skillmd.com/u/aeondave)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/aeondave/factordb

---


# FactorDB

The fastest factorization step is the one somebody else already paid for.

## When to use FactorDB

Use FactorDB when you need to:

- check whether a modulus or large integer is already known and factored
- retrieve small-to-medium factors quickly before deeper math work
- decide whether RSA triage should move to `sagemath`, `rsactftool`, or a different line of attack

## Quick Start

```bash
# Browser/API query
curl "https://factordb.com/api?query=5959"

# Example response shape
{"id":"5959","status":"FF","factors":[["59",1],["101",1]]}
```

## Practical Workflow

1. Query the target integer through the API or site.
2. Inspect `status` before trusting the result.
3. If factors are returned, convert them into your local math workflow.
4. If the number is still composite or partially factored, escalate to `sagemath`, ECM, or a problem-specific attack.

## Common Uses

- RSA modulus triage
- `p - 1` or `q - 1` structure checks after recovering factors
- sanity-checking challenge integers before local brute force

## Practical Notes

- `FF` means fully factored in the typical workflow; partially solved composites need follow-up.
- FactorDB is a lookup service first, not a guaranteed live factorization oracle.
- Preserve source numbers exactly; dropped digits or formatting mistakes waste time and give false confidence.

## Caveats

- Large unfactored composites may return incomplete results.
- Internet dependence makes it unsuitable for isolated environments.
- Treat it as a reconnaissance accelerator, not as the whole cryptanalysis plan.

## Resources

No bundled `scripts/`, `references/`, or `assets/`.
Use the public API endpoint and site UI for current status and factor-list formatting.