arthiqlabs/vedaksha

**Clean-room Rust ephemeris and Vedic astrology engine, built for the agentic-AI era.** Sub-arcsecond planetary precision, every algorithm traced to a primary source, any chart queryable as a property graph.
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clean-room · 0.103″ mean longitude vs JPL Horizons · 1,147 tests (per push) + 24,350 oracle rows · MCP-native · BUSL-1.1 → Apache 2.0
Install · Quick start · Accuracy · What's inside · MCP + property graph · Provenance · License
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Install
| Platform | Install | Notes |
|----------|---------|-------|
| Rust | cargo add vedaksha | full pipeline |
| Python | pip install vedaksha | engine via WebAssembly, py3-none-any, Python ≥ 3.9 — no Rust toolchain |
| WASM | npm install vedaksha-wasm | browser & edge, no data files |
| MCP | cargo install vedaksha-mcp | stdio + HTTP (bearer auth) |
| Docker | docker run -e VEDAKSHA_MCP_TOKEN=… -p 3100:3100 ghcr.io/arthiqlabs/vedaksha-mcp | multi-arch (amd64 + arm64) |
Compute **janam kundali** (natal charts), **panchanga**, **dashas**, **nakshatras**, **vargas**, **shadbala**, **ashtakavarga**, **muhurta** and **transits/gochara** from a sub-arcsecond ephemeris (VSOP87A, ELP/MPP02, JPL DE440s/DE441).
Quick start
The Rust path is a compiled doctest in crates/vedaksha/src/lib.rs.
**Every Julian Day on the public surfaces is UT1**, not TT and not TDB. The engine converts to TT internally for the dynamical terms and uses UT1 for Earth rotation, which fixes the ascendant, MC and all twelve cusps. Passing a TDB Julian Day adds ΔT worth of rotation instead of removing it — 0.289° (17.3′) at today's ΔT ≈ 69 s, on every cusp. The one exception is the raw SPK query (state_vector), which indexes the kernel directly and takes TDB.
Accuracy
These figures are reproducible, not just asserted: vedaksha-parity
is a separate harness (maintained by the same authors as this engine) that anyone can run against
their own copies of the reference kernels to check the published numbers below.
Every figure is printed by a named test. Reproduce the ephemeris tables with bash scripts/download_de440s.sh, then cargo test -p vedaksha-ephem-core --release -- --include-ignored --nocapture; the ayanamsha figures come from cargo test -p vedaksha-astro sidereal, and the cross-check against an independent Python derivation of the same primaries from cargo test -p vedaksha-astro --test ayanamsha_fixture.
**What the headline 0.103″ measures — precisely.** It is a mean *apparent geocentric ecliptic-longitude* residual, not a general position-accuracy figure: the fixture also carries ref_latitude, ref_distance and ref_speed, but oracle_comparison.rs marks them dead_code and none of the three enters this number. It covers only the measured-ΔT era, 1900–2025, at 1,535 comparisons per body (15,350 total across 10 bodies) — the full 1900–2100 grid moves the mean to 0.878″ for reasons unrelated to ephemeris accuracy (see below). And it compares against **planetary-system barycentres**, not physical planet centres, matching what the DE440s kernel stores and what SpkReader returns; querying centres instead would inject a spurious ~0.1″ offset for the outer planets (scripts/generate_horizons_oracle.py) — the same order of magnitude as the headline mean itself. These three facts are also published as data in metrics.json's accuracy block (quantity, era, targetConvention), so the site renders them rather than anyone hand-copying this paragraph.
**SpkReader vs JPL Horizons (DE441)** — oracle_comparison.rs, 24,350 committed rows (10 bodies × 2,435 dates, 1900–2100). Horizons serves DE441, so this measures our DE440s pipeline against an independent kernel.
| Era | Comparisons | Mean | Max |
|-----|-------------|------|-----|
| 1900–2025 (ΔT measured) | 15,350 | **0.103″** | 1.187″ (Uranus) |
| 1900–2100 (all) | 24,350 | 0.878″ | 44.912″ (Moon, 2099) |
15,349 of 15,350 comparisons before 2026 are sub-arcsecond. **Past 2025 the residual is ΔT prediction, not ephemeris error:** our Espenak–Meeus extrapolation and Horizons' ΔT diverge by ~68 s at 2099, and the error scales with a body's angular rate — the Moon (0.64″/s) picks up ~45″, Pluto essentially none. At 2099-02-06, five bodies spanning 0.03–0.64″/s all imply the same 66–71 s offset, which is the signature of a clock difference, not a position error.