Which harmonic does the API support?

Five harmonics: 1st (360 degrees), 2nd (180 degrees), 4th (22.5 degrees), 8th (11.25 degrees), and 16th (5.625 degrees). Pass the harmonic param as an integer in {1, 2, 4, 8, 16}. The default is 4 because the 4th harmonic 22.5 degree grid is what most working Cosmobiologers expect and what Ebertin established as the standard.

Why is the 4th harmonic / 22.5 degree grid the Cosmobiology standard?

Because it captures the four classical hard aspects (conjunction at 0, square at 90, opposition at 180, and semi-square at 45) plus the sesquisquare (135) and the eighth-cycle points (22.5 and 67.5) in one folded grid. Ebertin built Cosmobiology around hard aspects and midpoints, so any aspect within that family becomes a single line crossing on the graph. Wider harmonics hide those crossings; narrower harmonics fragment them.

How long a window can I render?

From one week up to ten years in a single request. The default sampling step is one day, which gives smooth lines for outer planets and acceptable lines for inner planets. For windows under one month with focus on Sun, Mercury, or Venus, drop the step to one hour to capture station retrograde curves. Render time scales roughly linearly with window length and planet count.

How does the SVG layer naming work for styling?

Every series sits in a g element with a stable class name. Transiting planets use g class=planet-{name}, for example planet-sun, planet-mars. Natal points use g class=natal-{name}. The harmonic grid is in g class=grid-harmonic, time ticks in g class=grid-time, retrograde shading in g class=retrograde-{planet}, and the legend in g class=legend. CSS rules and D3 selectors can target any of these directly without parsing the SVG.

How does this compare to Solar Fire, Janus, and Astrodienst?

Solar Fire and Janus produce excellent graphic ephemerides but they are desktop applications with no public API, and they export PNG or PDF rather than restyleable SVG. Astrodienst offers limited online graphs without a programmatic endpoint. The /render/graphic-ephemeris endpoint gives you the same Ebertin 22.5 degree grid through a JSON-in, SVG-out REST call, with named layers so the output can be themed, animated, or embedded in any web app.

What is the difference between the graphic ephemeris and the transit Gantt?

The graphic ephemeris is a time-by-degree graph: continuous planet lines crossing a harmonic grid, showing the big picture across the whole window. The transit Gantt (POST /api/v3/render/transit-gantt) is a horizontal bar chart: one row per transit-to-natal aspect, bars showing the date span the aspect is within orb. Use the graphic ephemeris for forecasting overviews, use the Gantt for precise scheduling.

How much does the Graphic Ephemeris API cost?

$11 per month for 1,000 requests on the Starter plan. $37 per month for 55,000 requests on the Professional plan. $99 per month for 220,000 requests and all endpoints on the Business plan. A free tier ships 50 requests per month forever, no credit card required. Both /render/graphic-ephemeris and the sister /render/transit-gantt count against the same quota.

How accurate are the planetary positions in the graph?

Planetary positions are accurate to 1 arcsecond. The API uses Swiss Ephemeris under the hood, the same engine that powers Solar Fire, Janus, Kepler, and Astrodienst. Line sampling happens at the configured step (default 1 day, overrideable to 1 hour), and the SVG renderer interpolates linearly between samples, which is visually indistinguishable from a continuous curve for any realistic window.

Can I restyle the colors and fonts in the SVG?

Yes. The default palette matches Ebertin's print convention, but every per-planet color, every per-natal color, the grid stroke, the background, and the legend font can be overridden via the styling block in the request. You can also leave styling alone and apply a CSS stylesheet to the named layers (g class=planet-sun {stroke: orange}) on the client side. Both paths produce the same result.

How fast is the render?

A typical 2-year window with 5 planets at the 4th harmonic renders in about 500 milliseconds. Render time scales roughly linearly with window length and the number of selected planets. A 10-year, 10-planet, 16th harmonic render with hourly sampling is the heaviest realistic call and lands around 3 to 4 seconds. The default settings keep the response well under 1 second.

Can I generate transit Gantt charts from the same payload?

Yes. POST /api/v3/render/transit-gantt accepts the same natal payload and the same date window. It returns SVG with named layers (g class=aspect-{transit}-{natal}) for each transit-to-natal aspect inside the window. Run both endpoints with the same request body and you get a matched pair: the graphic ephemeris for the big picture and the Gantt for the date-by-date schedule.

Does the SVG include retrograde shading and ingress markers?

Yes. Retrograde periods for each plotted planet render as shaded bands inside g class=retrograde-{planet}. Sign and harmonic-band ingresses render as vertical tick marks inside g class=ingress, each tagged with the date and the planet name. Both can be toggled off with show_retrograde=false and show_ingresses=false if you want a cleaner graph.

How do I embed the SVG in a Next.js or React app?

The response body is plain SVG text. Save it as a file and import it, fetch it at request time and inject with dangerouslySetInnerHTML, or render it as a React component via a tool like svgr. Because layers are named with stable classes, you can attach React event handlers via CSS selectors or rehydrate the SVG into D3 for interactivity without re-rendering on the server.

What house system does the natal block use?

The natal block accepts any house system the natal API supports: Placidus (default), Whole Sign, Equal House, Koch, Porphyry, Regiomontanus, Campanus, and more. For Cosmobiology purists, Whole Sign or Placidus are the typical picks. The chosen house system only matters for the natal ASC, MC, and house cusps shown as horizontal reference lines; transiting planet longitudes are house-system-independent.

Cosmobiology Visualization

Ebertin-Style Graphic Ephemeris as Production SVG

POST /api/v3/render/graphic-ephemeris returns a finished SVG: a time-by-degree grid where planets are plotted as continuous lines crossing horizontal degree bands.

Pick the harmonic (1st, 2nd, 4th, 8th, or 16th), pick the planets, pick the window (months to years), and drop the SVG into a client report or a forecasting dashboard. Natal points render as horizontal reference lines. Every series ships in a named layer like g class equals planet-sun, so downstream CSS or D3 can style it directly.

View API Docs

Harmonics: 1st, 2nd, 4th (Ebertin), 8th, 16th

~500ms

Two-year window render time

22.5 deg

Ebertin Cosmobiology standard grid

SVG layers

Named per-planet and per-natal groups

1-arcsecond planetary precision (Swiss Ephemeris)

SVG with named layers, no rasterization

99.9% uptime SLA

Generic chart APIs return single-moment wheels, not time-series graphs
PNG-only output cannot be restyled, themed, or made interactive on the client
Hard-coded tropical zodiac grid forces a 30 degree band, breaking Cosmobiology workflows
No 4th harmonic (22.5 degree) option, the Ebertin standard since 1936
Natal points are missing or baked into the image as static pixels
Multi-year windows time out or get truncated to a few weeks

Render with

Ebertin-style time-by-degree grid as SVG, with continuous planet lines crossing horizontal degree bands
Harmonic selector: 1st (360 deg), 2nd (180 deg), 4th (22.5 deg, Ebertin), 8th (11.25 deg), 16th (5.625 deg)
Configurable window: weeks, months, or multi-year, with one-day default sampling
Per-planet selection, retrograde shading, and ingress markers on every series
Natal points render as horizontal reference lines in their own SVG layer
Named layers: g class equals planet-sun, g class equals natal-mc, ready for CSS or D3 styling

Graphic Ephemeris API at a glance

One endpoint, five harmonics, SVG output

~500ms

Two-year render time

Supported harmonics

22.5 deg

Ebertin grid resolution

1 arcsec

Planetary precision

Graphic Ephemeris feature list

Everything the /render/graphic-ephemeris endpoint exposes

Ebertin 4th harmonic default

22.5 degree folded grid, the Cosmobiology standard since 1936

harmonic param defaults to 4; pass 1, 2, 8, or 16 to switch

Five harmonic options

1st (360 deg), 2nd (180 deg), 4th (22.5 deg), 8th (11.25 deg), 16th (5.625 deg)

Integer harmonic in {1, 2, 4, 8, 16}

SVG output with named layers

Per-planet and per-natal-point groups for direct CSS or D3 styling

g class=planet-{name}, g class=natal-{name}, g class=grid-harmonic

Multi-year date windows

Weeks to ten years in a single request, configurable sampling step

start_date, end_date as ISO 8601; step in {1h, 6h, 1d, 1w}

Natal reference lines

Natal planets, ASC, MC, and lots as horizontal lines folded to the chosen harmonic

include_natal block; outer-planet lines dashed by default

Retrograde shading

Per-planet retrograde periods rendered as shaded bands

g class=retrograde-{planet}, default visible, can be hidden

Ingress markers

Vertical tick marks for sign and harmonic-band ingresses

g class=ingress, includes date label and planet name

Per-planet selection

Choose any subset of 13 bodies including Chiron and the lunar nodes

planets array; Moon off by default for windows > 3 months

Styleable Ebertin palette

Default colors match the classic Ebertin print convention; overrideable

styling.colors.{planet} accepts hex strings

Swiss Ephemeris core

1-arcsecond planetary precision, same engine professional software uses

Internally uses pyswisseph under the hood

Companion transit Gantt

Sister endpoint renders aspect timing windows as horizontal bars

POST /api/v3/render/transit-gantt, same natal payload accepted

Fast render times

Typical 2-year, 5-planet, 4th harmonic graph renders in around 500 ms

P95 under 800 ms for default settings; scales linearly with window length

Graphic Ephemeris API: Ebertin 22.5 degree grid as SVG

A time-by-degree visualization for Cosmobiology, forecasting, and pro-grade client reports

A graphic ephemeris is a time-by-degree grid. The horizontal axis is time. The vertical axis is degrees of the zodiac, folded into a chosen harmonic. Each planet is plotted as a continuous line that sweeps left to right and crosses horizontal bands as it moves. The aspects you care about jump out as line crossings, not table rows. Reinhold Ebertin published the 4th harmonic (22.5 degree) version in The Combination of Stellar Influences in 1936, and it has been the Cosmobiology standard ever since. POST /api/v3/render/graphic-ephemeris returns the finished graph as SVG. You pick the harmonic (1st, 2nd, 4th, 8th, or 16th), the planet set, the date window (weeks to years), the sampling step, and whether to include natal points as horizontal reference lines. Output is SVG with named layers, so you can theme it with CSS, animate it with D3, or drop it straight into a PDF.

What is a graphic ephemeris and why does it matter?

A graphic ephemeris collapses a printed ephemeris table into one image.

Instead of scanning 30 rows per month for Sun longitude, you see a single line that sweeps across the page.

The horizontal axis is time, typically one day per pixel column for a one-year view or one week per column for a five-year view.

The vertical axis is the zodiac, folded into the chosen harmonic.

In the 4th harmonic Ebertin layout, the vertical axis wraps every 22.5 degrees, so an aspect within the 4th harmonic family (conjunction, square, semi-square, sesquisquare, opposition) shows up as a line crossing another line.

The 4th harmonic is the Cosmobiology standard because it captures the four classical hard aspects (0, 45, 90, 180) in one folded grid plus the semi-square family (22.5, 67.5).

The /render/graphic-ephemeris endpoint renders this graph as SVG: continuous planet lines, optional natal reference lines, retrograde shading, and ingress markers, all in named layers.

4th harmonic = 22.5 degree grid, the Ebertin Cosmobiology standard since 1936

1 min read

Harmonic selector: 1st, 2nd, 4th, 8th, 16th

The harmonic param controls how the vertical axis folds.

The 1st harmonic spans a full 360 degrees: planet lines run from 0 to 360 and wrap, with sign boundaries at every 30 degrees.

The 2nd harmonic folds at 180 degrees and exposes oppositions as line crossings.

The 4th harmonic folds at 22.5 degrees and is the Ebertin Cosmobiology standard: it surfaces hard aspects from the 4th harmonic family (conjunction, semi-square, square, sesquisquare, opposition) plus the 22.5 and 67.5 degree positions.

The 8th harmonic folds at 11.25 degrees and adds the 11.25, 33.75, 56.25, 78.75 degree positions, useful for fine-grained timing work.

The 16th harmonic folds at 5.625 degrees and is the finest-grained option, mostly used for research and pattern detection in tight time windows.

Pass harmonic as an integer (1, 2, 4, 8, 16) in the request body.

Default is 4 because that is what most working Cosmobiologers expect.

1st = 360 deg, 2nd = 180 deg, 4th = 22.5 deg (Ebertin), 8th = 11.25 deg, 16th = 5.625 deg

1 min read

Window, sampling, and planet selection

The window param takes start_date and end_date as ISO strings.

Anything from one week to ten years renders fine.

The default sampling step is one day, which gives smooth lines for slow planets (Jupiter through Pluto) and accurate-enough lines for fast planets (Sun, Mercury, Venus, Mars).

For a Sun and Mercury close-up over a one-month window, drop the step to one hour and you will see the curves bend around station retrograde points.

The planets param accepts an array: sun, moon, mercury, venus, mars, jupiter, saturn, uranus, neptune, pluto, plus chiron and the lunar nodes.

Each planet renders in its own SVG layer with a default color from the Ebertin palette, but the color can be overridden per planet via the styling block.

The Moon is off by default for windows longer than three months, because the Moon line wraps the harmonic grid too often to be readable.

Window weeks to years, default 1-day sampling, 12+ selectable bodies

1 min read

Natal reference lines and how they render

Natal points render as horizontal lines that span the full width of the graph.

Pass the include_natal block with the natal data (date, time, location, house system if relevant) and the API computes the natal longitudes, folds them into the requested harmonic, and draws each as a horizontal reference line.

When a transiting planet line crosses a natal reference line, that is the visual representation of an aspect.

In the 4th harmonic grid, every horizontal crossing means the transiting planet is hitting the natal point with a hard aspect (0, 22.5, 45, 67.5, 90, 112.5, 135, 157.5, or 180 degrees).

Each natal point gets its own SVG layer: g class equals natal-sun, g class equals natal-mc, g class equals natal-asc, and so on.

Pluto, Neptune, and Uranus natal lines are dashed by default because they barely move in a multi-year window and the dash makes them easier to distinguish from transiting outer-planet lines.

Natal points as horizontal lines, hard aspects shown as line crossings

1 min read

Named SVG layers for downstream styling

Every series ships in a g element with a stable class name, so CSS, D3, or any DOM-aware tool can target it without parsing the SVG.

Transiting planets use g class equals planet-{name}, for example g class equals planet-sun, g class equals planet-mars.

Natal points use g class equals natal-{name}, for example g class equals natal-sun, g class equals natal-mc.

The grid lines (harmonic bands and time tick marks) sit in g class equals grid-harmonic and g class equals grid-time.

Retrograde shading sits in g class equals retrograde-{planet} so a CSS rule can recolor or hide it.

The legend is in g class equals legend and is stripped if legend equals false is passed.

Because the SVG is text, it gzip-compresses well: a 2-year, 4-planet, 4th-harmonic render is typically under 80 KB on the wire, and the markup is human-readable for debugging.

Stable class names (planet-{name}, natal-{name}), CSS-styleable, D3-targetable

1 min read

Pairing with the Transit Gantt endpoint

POST /api/v3/render/transit-gantt is the sister endpoint that ships in the same sprint.

Where the graphic ephemeris answers "what is happening across the whole window?", the transit Gantt answers "when exactly is each aspect inside its orb?" The Gantt is a horizontal bar chart: one row per transit-to-natal aspect, bars showing the date span the aspect is within orb, and shading showing the exact-hit point.

Use the graphic ephemeris for the big picture (forecasting newsletters, year-ahead overviews, Cosmobiology midpoint scans) and use the Gantt for the precise schedule (client booking windows, election timing, day-by-day blogs).

Both endpoints take the same natal payload and the same date window, so a single request set produces a matched pair of visuals for a report.

The Gantt returns SVG with the same named-layer convention: g class equals aspect-{transit}-{natal} for each row.

Companion endpoint /render/transit-gantt: aspect timing windows as bars

1 min read

Use Cases

Professional astrologers

Drop a 4th harmonic graph into a client report, no Solar Fire screenshot juggling

Cosmobiology specialists

Ebertin 22.5 degree grid as SVG, ready for midpoint and hard-aspect work

Astrology SaaS dashboards

Embed an interactive ephemeris in a forecasting app, restyle layers with CSS

Content publishers and newsletters

Generate a fresh year-ahead graphic for every editorial calendar slot

Educators and researchers

Compare harmonics side by side, export SVG for slides, papers, and books

Election astrologers

Spot crossing windows in the graph, then call /render/transit-gantt for exact dates

Technical Specifications

Endpoint	POST /api/v3/render/graphic-ephemeris
Output format	SVG (text/xml), gzip-compressible, no rasterization
Harmonic options	1 (360 deg), 2 (180 deg), 4 (22.5 deg, default), 8 (11.25 deg), 16 (5.625 deg)
Window range	1 week to 10 years, ISO 8601 start_date and end_date
Sampling step	Default 1 day; overrideable to 1 hour for fast planets
Selectable bodies	Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Chiron, North Node, South Node
Natal reference lines	Optional include_natal block; all natal planets, ASC, MC, lots render as horizontal lines
Named SVG layers	planet-{name}, natal-{name}, grid-harmonic, grid-time, retrograde-{planet}, legend
Retrograde shading	Per-planet retrograde periods rendered in retrograde-{planet} layer
Ingress markers	Sign and harmonic-band ingresses marked with vertical ticks
Planetary precision	1 arcsecond (Swiss Ephemeris under the hood)
Render time (2-year window, 5 planets, 4th harmonic)	~500ms
Payload size	~80 KB gzipped for a typical 2-year, 4-planet render
Sister endpoint	POST /api/v3/render/transit-gantt (aspect timing windows as bars)

Graphic Ephemeris API vs desktop software and other APIs

Feature	Astrology API	Others
Output format	SVG with named layers, restyle with CSS	PNG or PDF, baked-in styling
Harmonic options	1, 2, 4, 8, 16 (5 total)	Usually 1 only, sometimes 4
Ebertin 22.5 deg grid	First-class default	Solar Fire and Janus only on desktop
Natal reference lines	Per-point SVG layers, dashed for outer planets	Static pixels in image
Window length	1 week to 10 years	Often capped at 1 to 2 years
Sampling step	1 day default, 1 hour overrideable	Fixed daily sampling
Render time	~500ms server-side	Desktop only, no API
Pairing with Gantt	Sister /render/transit-gantt endpoint	Separate tool or none
Pricing	From $11/month, free tier available	$300+ one-time (Solar Fire) or no API access
Programmatic access	REST POST, JSON in, SVG out	GUI only or no public API

Related visualization and timing APIs

Chart SVG API

Natal, transit, synastry, and composite chart wheels as SVG

Transit API

Current planetary aspects to the natal chart, JSON payload

Timing API hub

Annual, monthly, daily, and continuous timing techniques in one suite

Profections API

Hellenistic profections with Lord of the Year and biwheel overlays

Zodiacal Releasing

L1 to L4 periods from Spirit and Fortune with peak detection

Eclipse API

Solar and lunar eclipse dates, magnitudes, and natal contacts

References & Standards

Swiss Ephemeris (DE431-based) — astronomical calculations source
NASA JPL Planetary Ephemerides — underlying ephemeris dataset
International Astronomical Union (IAU) — body designation and nomenclature standards
IANA Time Zone Database — timezone & DST resolution

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All basic endpoints
12 house systems
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$21/month

For growing apps and medium traffic

All enhanced endpoints
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$37/month

For professional astrology applications

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Graphic Ephemeris API FAQ

What developers, astrologers, and SaaS teams actually ask

Build a complete forecasting toolkit

Pair the Graphic Ephemeris API with the other visualization and timing endpoints:

Chart SVG API Transit API Timing API hub Profections Zodiacal Releasing Eclipse API

Ship a graphic ephemeris in one

POST /api/v3/render/graphic-ephemeris returns the Ebertin-style time-by-degree grid as SVG. Five harmonics, multi-year windows, natal reference lines, named layers for CSS styling. Sub-second renders. Pair with /render/transit-gantt for exact aspect timing.

Start Free Now Read API Docs

50 free requests per month, forever

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No setup fees, no credit card to start

Ebertin-Style Graphic Ephemeris as Production SVG

Why most APIs cannot render a real graphic ephemeris

What POST /api/v3/render/graphic-ephemeris ships

Graphic Ephemeris API at a glance

Graphic Ephemeris feature list

Ebertin 4th harmonic default

Five harmonic options

SVG output with named layers

Multi-year date windows

Natal reference lines

Retrograde shading

Ingress markers

Per-planet selection

Styleable Ebertin palette

Swiss Ephemeris core

Companion transit Gantt

Fast render times

Graphic Ephemeris API: Ebertin 22.5 degree grid as SVG

What is a graphic ephemeris and why does it matter?

Harmonic selector: 1st, 2nd, 4th, 8th, 16th

Window, sampling, and planet selection

Natal reference lines and how they render

Named SVG layers for downstream styling

Pairing with the Transit Gantt endpoint

Use Cases

Professional astrologers

Cosmobiology specialists

Astrology SaaS dashboards

Content publishers and newsletters

Educators and researchers

Election astrologers

Technical Specifications

Graphic Ephemeris API vs desktop software and other APIs

Related visualization and timing APIs

Chart SVG API

Transit API

Timing API hub

Profections API

Zodiacal Releasing

Eclipse API

References & Standards

Simple, Transparent Pricing

Always Free

Pro

Pro Plus

Ultra

High Volume Plans

Business

Enterprise

Graphic Ephemeris API FAQ

What is a graphic ephemeris?

Which harmonic does the API support?

Why is the 4th harmonic / 22.5 degree grid the Cosmobiology standard?

Can I include natal points as horizontal reference lines?

How long a window can I render?

How does the SVG layer naming work for styling?

How does this compare to Solar Fire, Janus, and Astrodienst?

What is the difference between the graphic ephemeris and the transit Gantt?

How much does the Graphic Ephemeris API cost?

How accurate are the planetary positions in the graph?

Can I restyle the colors and fonts in the SVG?

How fast is the render?

Can I generate transit Gantt charts from the same payload?

Which bodies can I plot?

Does the SVG include retrograde shading and ingress markers?

How do I embed the SVG in a Next.js or React app?

What house system does the natal block use?

Build a complete forecasting toolkit

Ship a graphic ephemeris in one

Why most APIs cannot render a real graphic ephemeris

What POST /api/v3/render/graphic-ephemeris ships

Graphic Ephemeris API at a glance

Graphic Ephemeris feature list

Ebertin 4th harmonic default

Five harmonic options

SVG output with named layers

Multi-year date windows

Natal reference lines

Retrograde shading

Ingress markers