→ Spearhead APIPrivate-market valuation dataIllustrative / backtest

Calibrated marks with clear provenance
for API consumers

Every response is a read-only JSON record: latest mark, interval, source references, and a complete meta envelope so downstream systems can validate what they receive.

Base path

/v1

Auth

X-API-Key

Universe

33 names

Intervals

80% / 95%

Methodology

v0.2.0

Data mode

illustrative / backtest

Names covered

80 / 95%

Intervals

80.8%

Interval coverage

IPO validations

Audit

Provenance per payload

DATA: FIXTURE | BACKTEST

00 / Why this API

Why this API is different

Most valuation feeds are numbers. Spearhead provides numbers with evidence and versioned behavior.

Model outputs include uncertainty

We return both point estimate and interval so teams can decide if a mark is decision-ready for the context it is used in.

Accuracy is tracked in public

Reliability, coverage, and misses are published in scorecards. It is not a one-way signal.

Provenance is first-class

The meta block on every payload includes methodology, dataset, timestamp, and backtest vs live labels. You can gate usage by those fields.

Market comparison posture

In the latest competitive sweep (18 vendors), only 0 publish walk-forward backtests and 0 publish calibration disclosure. Spearhead keeps both visible in product routes.

01 / Quickstart

Start in 3 simple steps

Get a key

Start a free checkout at /api/checkout?tier=research, then use the issued API key.

Call the API

Use any endpoint under /v1. The free tier includes the top-10 list and latest mark path.

Read the envelope

Before using any value, verify meta.data_mode and meta.provenance on each response.

Request examplecurl

export SPEARHEAD_API_KEY=sph_test_example_key

curl -sS "https://api.pegasusthreesixty.com/v1/companies/coreweave?coverage=80" \
  -H "X-API-Key: $SPEARHEAD_API_KEY"

Response example200 OK

{
  "meta": {
    "data_mode": "illustrative",
    "provenance": "backtest",
    "methodology_version": "v0.2.0",
    "dataset_version": "2026-06-14",
    "as_of": "2026-06-10",
    "disclaimer": "Illustrative backtest derived from public events."
  },
  "slug": "coreweave",
  "name": "CoreWeave",
  "sector": "AI Cloud Infrastructure",
  "latest_mark": {
    "as_of_date": "2025-03-27",
    "value_usd": 22062735430,
    "lower_usd": 10903281498,
    "upper_usd": 44643834494,
    "confidence": 0.791
  }
}

02 / Endpoints

Endpoint overview

All endpoints are read-only and versioned under /v1.

GET/v1/companiesCoverage universe and status filtering.

GET/v1/companies/{slug}Profile, latest mark, observations.

GET/v1/companies/{slug}/marksHistorical marks with 80 or 95 conformal bands.

GET/v1/companies/{slug}/eventsAppend-only event log with revisions.

GET/v1/companies/{slug}/resolutionEnterprise: signed resolution record and audit payload.

GET/v1/usageCurrent key's rate limits and entitlement.

03 / FAQ

Implementation notes

What does the API return?

Each endpoint returns a read-only JSON payload for one company or list. Every response includes metadata (data_mode, provenance, methodology_version, dataset_version, as_of) so downstream systems can validate assumptions before using values. All figures are illustrative / backtest and are not investment advice.

How do I get started?

Start the free Research tier, complete checkout, and then use the issued key in the X-API-Key header. You get access to the company list and latest mark endpoints. All figures are illustrative / backtest and are not investment advice.

Are values live?

Not yet. Every payload is explicitly marked with data_mode=illustrative and provenance=backtest, and live values are not published in this release. All figures are illustrative / backtest and are not investment advice.

How is accuracy measured?

A public scorecard publishes quarterly reliability, Brier score, and interval coverage, and includes known misses and model caveats.

04 / Contracts

Contract stability

Cloud-friendly stability

Contract fields under /v1 are additive. Breaking changes are reserved for explicit version increments and published migration windows.

Read the full /v1 contract, including pagination, rate limits, and error codes.

05 / Honesty

What this service can and cannot do

Illustrative / backtest - not live marks. Indicative valuations, not transactable prices. Underlying assets are illiquid; inputs are limited to publicly reported events with source attribution. Pegasus Three Sixty and SpearHead are an information-only valuation product, do not hold client balances, and do not provide investment recommendations.