What is birth time rectification and why does it matter for astrology apps?

Birth time rectification finds the exact birth time when only an approximate time is known. A 4-minute error shifts the Ascendant by about 1 degree, which changes house cusps and breaks every house-based prediction. If your app offers transits, progressions, or solar return analysis, inaccurate birth time makes all of it unreliable. The rectification API lets your users fix this by correlating known life events with chart signatures.

How much does the Rectification API cost?

15 credits per request, flat rate regardless of candidates or events. Free tier: 50 requests/month. Starter: $11/month for 1,000 requests. Professional: $37/month for 55,000 requests. Compare to professional astrologers charging $200-$500 per manual rectification taking 2-6 hours.

What life events can I use for rectification?

18 event categories: marriage, divorce, child_birth, death_family, career_change, career_promotion, job_loss, move, accident, surgery, health_diagnosis, education, relationship_start, relationship_end, financial_gain, financial_loss, spiritual, other. Each has a default astrological weight (1-10) that you can override per-event. The GET /glossary/event-categories endpoint returns all categories with labels, descriptions, and NLP synonyms.

How many events do I need for accurate rectification?

Minimum 1, maximum 50. In practice, 3-7 events with exact dates across different life areas produce the best results. More events with varied categories give the engine more angles to discriminate between candidates. Events with only year-level precision (date_precision: 'year') still contribute but at 0.4x weight, while month-level events score at 0.7x.

What is Schmidt sect doctrine and why does it matter?

Hellenistic sect distinguishes planets by day vs night chart. Most software ignores this or uses simple day/night binary. Our engine implements Schmidt's full 5-cell differentiation: sect light (1.20x), sect benefic (1.10x in positive events), sect malefic ('tame', 0.95-1.05x), and out-of-sect malefic ('wild', 0.85-1.20x depending on event type). Plus twilight smoothing near the horizon. This dramatically improves discrimination between candidates.

How fast is the rectification search?

Single-candidate evaluation: under 1 second. A typical search of 30 candidates across 7 events completes in under 60 seconds. 100 candidates with 7 events takes about 3 minutes. Performance scales linearly with candidates multiplied by events. The single-moment mode (N=1 candidate) responds in under 1 second, useful for wizard-style UIs where users drag a time slider.

How do I specify the search window?

Two modes. Mode A: set delta_minutes (1-720) for plus-or-minus N minutes around the subject's anchor time. Mode B: set explicit start and end times in HH:MM format. Both modes accept step_minutes (1-60, default 4) controlling the interval between candidates. Default 4 minutes corresponds to roughly 1 degree of ASC rotation at mid-latitudes.

Can I filter candidates by Ascendant sign?

Yes. Set ascendant_sign to a sign abbreviation (Ari, Tau, Gem, etc.). Candidates whose computed ASC falls outside that sign get excluded=true in the response rather than being removed. This lets your UI grey them out without hiding the data. Useful when the astrologer has a strong suspicion about the rising sign.

What is the confidence assessment?

The response includes a confidence object with level (high/medium/low/n_a), gap_ratio (score gap between first and second place divided by first), and lift_ratio (first place score divided by mean). High confidence means one candidate clearly separates from the pack. Low confidence with anchor_grade=true still has diagnostic value. The quality_advisory field warns when results are weak.

What programming languages work with the Rectification API?

Any language with HTTP support. The API is standard REST returning JSON. Official SDKs for JavaScript/Node.js, Python, PHP, Ruby. The request/response schemas are fully typed with Pydantic models and OpenAPI spec. Most developers integrate using fetch, axios, or requests in under 30 minutes.

Can I use this with AI agents and LLMs?

Yes. The rectification_search tool is registered as MCP-callable and tagged chat-safe. Chat projection returns compact top-3 results with ASC/MC positions, grade, and strongest evidence per candidate. Works out of the box with Claude, ChatGPT function calling, and custom AI agent frameworks.

What is the evaluator traces feature?

Set include_evaluator_traces: true in the request. Each candidate in the response then includes a list of all 18 registered evaluators with fired/not-fired status, adjusted_points, and reason string. This is for working astrologers who want to see exactly which minute peaks for a specific evaluator, or for debugging and research workflows.

How accurate is the rectification engine?

The engine uses Swiss Ephemeris JPL DE431 data (same source as NASA). Planetary positions are accurate to 0.001 arc-seconds. Scoring is calibrated against published case studies. However, rectification accuracy also depends on input quality: precise event dates, correct categories, and at least 3-5 well-distributed life events produce the most discriminating results.

Is there a free tier for the Rectification API?

Yes. 50 free requests every month, no credit card required. That covers enough to test the full flow, validate against known birth times, and prototype your integration. All features are included in the free tier. No feature gating.

What house systems does the rectification engine support?

All house systems our platform supports: Placidus (default), Whole Sign, Koch, Regiomontanus, Campanus, Equal, Morinus, Porphyry, and KP (Krishnamurti). This means you can run rectification for both Western and Vedic/KP-based astrology. House rulers used by evaluators adapt to the chosen system.

What is the twin_window flag?

When gap_ratio drops below 0.005 (top-2 candidates within 0.5% of each other), twin_window becomes true. This means the engine cannot meaningfully distinguish the top candidates at minute-level precision. Present these results as 'sub-minute uncertainty' rather than a single definitive peak. Common when events lack angular signatures.

Can I use partial event dates (month or year only)?

Yes. Each event accepts date_precision: 'exact' (YYYY-MM-DD, full weight), 'month' (YYYY-MM, 0.7x weight using 15th as midpoint), or 'year' (YYYY, 0.4x weight using July 1). The format must match precision. Partial dates still contribute to scoring but with reduced influence, reflecting the inherent uncertainty.

Birth Time Rectification

Rectify Birth Time in Under 60 Seconds. With Evidence.

First REST API for automated birth time rectification.

18 evaluators across transit, secondary progression, and solar arc. Schmidt sect doctrine, eclipse-on-angle anchoring (Brady), Saros-family resonance. Submit life events, get ranked candidate times with full scoring evidence. No other API does this.

View Documentation

Factor Evaluators

Scoring Techniques

Event Categories

Languages

First rectification REST API

Swiss Ephemeris precision

MCP-ready for AI agents

Professional astrologers charge $200-$500 per rectification, spending 2-6 hours on a single chart
Desktop software (Solar Fire, Janus) requires manual checking of transits for each candidate time
No existing API offers automated rectification scoring of any kind
Online calculators give vague results without showing their work or methodology
Building your own engine requires deep knowledge of Hellenistic sect, solar arc, progressions, and eclipses

Transform with

18 evaluators score every candidate minute against your life events automatically
Three classical techniques combined: transit, secondary progression, solar arc direction
Schmidt sect doctrine with twilight smoothing, not just day/night binary
Eclipse-on-angle anchoring per Brady as tie-breaker for close scores
Transparent scoring with per-check evidence, confidence level, and quality advisory

Rectification Engine Performance

Built for production, validated against published case studies

Factor Evaluators

Techniques Combined

Event Categories

<1s

Single Candidate

282 tests

Test Coverage

13 languages

Localized Output

Complete Rectification Engine Features

18 evaluators, 3 techniques, Schmidt sect, eclipse anchoring

Transit Evaluators (8 checks)

Progression Evaluators (5 checks)

Solar Arc Evaluators (3 checks)

Scoring Intelligence

Response & Diagnostics

What Is Birth Time Rectification API? Complete Developer Guide

The first REST endpoint for automated astrological birth time correction

What is birth time rectification? It is the process of finding someone's exact birth time when only an approximate time is known. A 4-minute error shifts the Ascendant by about 1 degree, which changes house cusps and throws off every timing technique built on angular positions. Professional astrologers solve this by correlating known life events (marriage, career change, accident) with chart signatures that should have been active at those times. The candidate time whose chart best explains all the events wins. Our Birth Time Rectification API automates this entire process. You send a birth date, approximate time window, and a list of life events. The engine generates candidate times at configurable intervals (down to 1-minute steps), computes natal + transit + progressed + solar-arc charts for each candidate against each event, runs 18 factor evaluators with Schmidt sect doctrine and eclipse anchoring, then returns ranked results with full scoring evidence. No other API does automated rectification. We checked every provider: AstrologyAPI.com, Prokerala, KundliAPI, VedicRishi. Confirmed empty market.

How does the Rectification API work?

One endpoint powers everything: POST /api/v3/rectification/search.

You send a subject (birth date + approximate time), a time_search window (either delta_minutes around the anchor, or explicit start/end range), and a list of life events with dates and categories.

The engine generates candidate birth times at your chosen step size (default 4 minutes, roughly 1 degree of ASC rotation at mid-latitudes).

For each candidate, it computes a full natal chart, then for each event it computes the transit chart, secondary progressed chart, and solar-arc directed chart at the event date.

All 18 evaluators fire against each (candidate, event) pair.

Results pass through sect multiplier, event-affinity boost, and normalization against a theoretical maximum.

You get back ranked candidates with aggregate scores, per-event breakdowns, confidence assessment, and optional density data for histogram rendering.

One endpoint, 18 evaluators, 3 techniques per candidate per event

1 min read

What techniques does the rectification engine use?

Three classical predictive techniques, each contributing distinct evaluators.

Transit evaluators (8 checks): outer planet conjunctions to angles, hard aspects to angles, conjunctions to house rulers, Mars/Jupiter to angles, eclipse-on-angle (with Saros-family resonance), and lunar nodes on angles.

Progression evaluators (5 checks): progressed angle conjunct natal planet, progressed Moon in relevant house, progressed Moon aspecting angles, progressed Sun sign change near event, and progressed New/Full Moon.

Solar arc evaluators (3 checks): SA-directed planet to angle, SA-directed angle to natal planet, and SA planet to house ruler.

Modern co-rulers (Pluto for Scorpio, Uranus for Aquarius, Neptune for Pisces) are tested alongside traditional rulers at a reduced weight.

8 transit + 5 progression + 3 solar arc + 2 eclipse evaluators

1 min read

How does Schmidt sect doctrine improve scoring?

Most rectification software treats all planets equally.

Ours implements the full Schmidt 5-cell differentiation from Hellenistic Astrology.

The sect light (Sun in day charts, Moon in night charts) gets a 1.20x boost always.

The sect benefic (Jupiter by day, Venus by night) gets 1.10x in positive events.

The sect malefic (Saturn by day, Mars by night) is 'tame' (0.95x in positive events, 1.05x in acute events like surgery or accidents).

The out-of-sect malefic (Mars by day, Saturn by night) is 'wild' (1.20x in acute events, 0.85x demotion in positive ones).

Near the horizon (within 5 degrees), sect is ambiguous, so multipliers interpolate linearly toward neutral 1.0.

This twilight smoothing prevents hard jumps at the exact horizon crossing.

5-cell sect doctrine with twilight smoothing, not binary day/night

1 min read

What is eclipse-on-angle anchoring and Saros resonance?

Per Bernadette Brady (The Eagle and the Lark), an eclipse hitting a natal angle within 1 degree for a Tier-1 life event (death, marriage, birth, accident, surgery, divorce) is the single most diagnostic rectification signal.

Our engine flags candidates with this signature as anchor_grade=true, providing anchor_evidence with eclipse type, angle, orb, and event details.

When aggregate scores are close between candidates, anchor-grade candidates get priority.

On top of this, Saros-family resonance boosts eclipse evaluators by 1.25x when the event eclipse belongs to the same Saros family as the native's prenatal lunation eclipse.

This follows Brady's strict doctrine: one Saros family per native, determined by whether the prenatal lunation was itself an eclipse.

Eclipse anchoring as tie-breaker + Saros-family 1.25x resonance boost

1 min read

How do I integrate the Rectification API?

Standard REST.

POST to /api/v3/rectification/search with your payload.

The subject uses our canonical Subject schema (name, birth_data with year/month/day/hour/minute/city/country_code).

time_search accepts either delta_minutes (plus-minus N minutes around the anchor) or explicit start/end HH:MM range with configurable step_minutes.

Events are an array of objects with date (ISO format, supporting partial YYYY-MM and YYYY), category (one of 18 options), optional weight override (1-10), and date_precision flag.

Response includes ranked candidates with full chart data, per-event scoring with individual checks, density data for histograms, and a summary with confidence level, peak_time, score statistics, and quality advisory.

Optional flags: include_interpretations for localized narrative text, include_evaluator_traces for per-evaluator firing details, ascendant_sign to flag candidates outside a suspected sign.

One POST endpoint, 15 credits, full evidence in response

1 min read

Who uses the Birth Time Rectification API?

Four segments.

(1) Astrology app developers building rectification wizards.

The response includes density data for rendering time-vs-score histograms, ranked candidates for list views, and per-event breakdowns for detail panels.

(2) AI chatbot builders using MCP integration.

The rectification_search tool works with Claude, ChatGPT, and custom agents.

Chat projection returns compact top-3 results with key evidence.

(3) Professional astrologers scaling their practice.

Instead of 2-6 hours per rectification, they get instant scored results with evaluator traces to review.

The transparency (applied_multipliers, check descriptions, orb values) lets them verify and override.

(4) Astrology SaaS platforms offering premium 'unknown birth time' features.

The confidence assessment and quality advisory provide guardrails for automated UX flows.

App builders, AI agents, professional astrologers, SaaS platforms

1 min read

Use Cases

Astrology App Rectification Wizard

Build step-by-step UIs: collect events, show time-score histogram from density data, present ranked candidates with evidence.

AI Agent / MCP Integration

rectification_search MCP tool for Claude, ChatGPT, custom agents. Chat projection returns compact top-3 with key evidence.

Professional Astrologer Dashboard

Evaluator traces let astrologers see exactly which checks fired and why. Override or confirm with full transparency.

Unknown Birth Time Feature

SaaS platforms offer premium rectification to users with approximate times. Confidence assessment provides UX guardrails.

Vedic + Western Comparison

Run rectification with different house systems (Placidus, Whole Sign, KP). Compare results across traditions.

Research & Validation

Test rectification hypotheses programmatically. Include_evaluator_traces shows all 18 checks per candidate for analysis.

Technical Specifications

Endpoint	POST /api/v3/rectification/search
Cost	15 credits per request (flat)
Factor Evaluators	18 (8 transit + 5 progression + 3 solar arc + 2 eclipse)
Event Categories	18 (marriage, death_family, career_change, surgery, etc.)
Scoring Techniques	Transit + Secondary Progression + Solar Arc Direction
Sect Doctrine	Schmidt 5-cell with twilight smoothing (5-degree threshold)
Eclipse Anchoring	Brady eclipse-on-angle for Tier-1 events (1-degree orb)
Saros Resonance	1.25x boost when event eclipse matches prenatal Saros family
Normalization	Theoretical-max denominator per (category, techniques)
Confidence Levels	high / medium / low / n_a with gap_ratio and lift_ratio
Search Window	Up to 720 minutes (12 hours) with 1-60 minute steps
Max Candidates	500 per request
Max Events	50 per request (min 1 enabled)
House Systems	All supported (Placidus default, Whole Sign, Koch, KP, etc.)
Localization	13 languages for interpretations and advisory text

Rectification API vs Manual Methods vs Competitors

Feature	Astrology API	Others
Automation	Fully automated via REST API	Manual (2-6 hours per chart)
Techniques Combined	Transit + Progression + Solar Arc simultaneously	Usually 1 technique at a time
Scoring	Normalized 0-100 with per-check evidence	Subjective judgment
Sect Doctrine	Schmidt 5-cell with twilight smoothing	Rarely applied, or day/night binary only
Eclipse Analysis	Anchor-grade + Saros-family resonance	Manual eclipse lookup
Confidence Assessment	Statistical (gap_ratio, lift_ratio)	Astrologer's gut feel
Output Format	Structured JSON with charts	PDF reports or verbal
Time per Rectification	Under 60 seconds for 30 candidates	2-6 hours manual
API Access	REST endpoint, MCP tool	No API exists anywhere
Price	From $11/month (1,000 requests)	$200-$500 per consultation

Related Astrology APIs

Transit API

Real-time planetary transits powering the transit evaluators

Natal Chart API

Birth chart calculation underlying every candidate

Electional Astrology API

Finding optimal times (opposite direction from rectification)

Predictive API

Progressions and solar arc directions as standalone endpoints

Eclipse API

Eclipse data powering the anchor-grade evaluation

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Questions? Talk to our team

Frequently Asked Questions About Birth Time Rectification API

Technical answers for developers building rectification features

Complete Your Predictive Astrology Stack

Rectification API works with our other timing and calculation tools.

Transit API Natal Chart API Predictive API Electional API Eclipse API

Start Rectifying

First automated birth time rectification REST API. 18 evaluators, 3 techniques, full scoring evidence. No competitor has this.

Start Free View Documentation

50 free requests/month

Swiss Ephemeris precision

No setup fees

Free tier includes all features

Rectify Birth Time in Under 60 Seconds. With Evidence.

Rectification Is Still Manual and Expensive

Fully Automated Rectification Engine via REST API

Rectification Engine Performance

Complete Rectification Engine Features

Transit Evaluators (8 checks)

Progression Evaluators (5 checks)

Solar Arc Evaluators (3 checks)

Scoring Intelligence

Response & Diagnostics

What Is Birth Time Rectification API? Complete Developer Guide

How does the Rectification API work?

What techniques does the rectification engine use?

How does Schmidt sect doctrine improve scoring?

What is eclipse-on-angle anchoring and Saros resonance?

How do I integrate the Rectification API?

Who uses the Birth Time Rectification API?

Use Cases

Astrology App Rectification Wizard

AI Agent / MCP Integration

Professional Astrologer Dashboard

Unknown Birth Time Feature

Vedic + Western Comparison

Research & Validation

Technical Specifications

Rectification API vs Manual Methods vs Competitors

Related Astrology APIs

Transit API

Natal Chart API

Electional Astrology API

Predictive API

Eclipse API

Simple, Transparent Pricing

Always Free

Pro

Pro Plus

Ultra

High Volume Plans

Business

Enterprise

Frequently Asked Questions About Birth Time Rectification API

What is birth time rectification and why does it matter for astrology apps?

How does the Birth Time Rectification API work?

How much does the Rectification API cost?

What life events can I use for rectification?

How many events do I need for accurate rectification?

What is Schmidt sect doctrine and why does it matter?

What is eclipse-on-angle anchoring?

How fast is the rectification search?

How do I specify the search window?

Can I filter candidates by Ascendant sign?

What is the confidence assessment?

What programming languages work with the Rectification API?

Can I use this with AI agents and LLMs?

What is the evaluator traces feature?

How accurate is the rectification engine?

Is there a free tier for the Rectification API?

What house systems does the rectification engine support?

What is the twin_window flag?

Can I use partial event dates (month or year only)?

Complete Your Predictive Astrology Stack

Start Rectifying

Rectification Is Still Manual and Expensive

Fully Automated Rectification Engine via REST API

Rectification Engine Performance

Complete Rectification Engine Features

Transit Evaluators (8 checks)

Progression Evaluators (5 checks)

Solar Arc Evaluators (3 checks)

Scoring Intelligence

Response & Diagnostics

What Is Birth Time Rectification API? Complete Developer Guide

How does the Rectification API work?

What techniques does the rectification engine use?

How does Schmidt sect doctrine improve scoring?

What is eclipse-on-angle anchoring and Saros resonance?

How do I integrate the Rectification API?

Who uses the Birth Time Rectification API?

Use Cases

Astrology App Rectification Wizard