Hey Product Hunt 👋 I'm Jackson — solo founder, and I built OpenEphemeris because every "astrology API" I tried either hallucinated planetary positions or hand-waved the math underneath them. This is a Go monolith computing sub-arcsecond positions straight from NASA's JPL DE440 kernel — the same data behind spacecraft navigation — across 120 REST endpoints. Every position is calculated, never guessed; you get clean JSON and typed errors, not prose to parse. If you use Claude: there's a 92-tool MCP server, and the part I most want to show is that it renders real interactive charts right inside the conversation — natal wheels, bodygraphs, bi-wheels, actually drawn, not screenshots of JSON (see the GIF). Ask in plain language and Claude reaches for the real numbers instead of making them up. Here's the honest reason this exists: a language model is extraordinary at meaning and tradition, and hopeless at coordinates — plausible is fine for prose and fatal for a planetary position, because a chart that's "close" lands in the wrong sign and inverts the whole reading. Astrology's interpretive half deserves a calculation half that is genuinely correct, so I built the deterministic layer the models were missing. The Explorer tier is free — a one-time grant of 150 credits, no card. (Note: connecting on claude.ai needs a paid Claude plan for custom connectors; Claude Desktop and Claude Code work on any plan.) I'd genuinely love feedback — on the accuracy, the MCP setup, the endpoint surface, or what you'd want it to compute next. What would you point it at? 🔭

OpenEphemeris

Astrology charts, computed and drawn inside Claude

Astrology charts, computed and drawn inside Claude