# Callrack

Instructions for agents working with this service.

## Payment
Every endpoint listed below is x402-paid. On HTTP 402, read the PAYMENT-REQUIRED response header (base64 JSON)
for the exact current payment requirement, pay the advertised amount in USDC on Algorand, then retry the same
request with a PAYMENT-SIGNATURE header carrying your payment proof.

## Important rule
Treat the live HTTP 402 payment requirement as authoritative. Never hardcode or assume a price from this file,
from `/llms.txt`, or from any prior response - always read the current 402 challenge before paying.

## Endpoints
- POST /v1/academic/search - Search scholarly literature via OpenAlex (falling back to Crossref) and return normalized works with titles, authors, publication years, DOIs, journals, citation counts, and open-access status. - 0.01 USDC per call.
- POST /v1/academic/work - Retrieve a single scholarly work by DOI via OpenAlex (falling back to Crossref) and return its normalized title, authors, publication year, journal, citation count, and open-access status. - 0.005 USDC per call.
- POST /v1/news/search - Search recent news coverage via GDELT and return normalized articles with titles, URLs, source domains, publish dates, languages, and countries. - 0.01 USDC per call.
- POST /v1/news/trends - Return normalized daily news-coverage volume for a topic, entity, or event via GDELT as a time series of dated volume points. - 0.02 USDC per call.
- POST /v1/crypto/price - Get current price and 24-hour change for one or more cryptocurrency assets in a specified quote currency via CoinGecko. - 0.002 USDC per call.
- POST /v1/crypto/market - Get market capitalization, rank, 24h volume, and circulating/total/max supply for one or more cryptocurrency assets via CoinGecko. - 0.005 USDC per call.
- POST /v1/fx/rates - Get current or historical foreign exchange reference rates for a base currency against one or more target currencies via Frankfurter (ECB data). - 0.002 USDC per call.
- POST /v1/weather - Get current conditions and a multi-day daily forecast (temperature, humidity, wind, precipitation) for a coordinate via Open-Meteo. - 0.003 USDC per call.
- POST /v1/geocode - Forward geocode a place name to coordinates, or reverse geocode coordinates to a place, via Photon, returning normalized address components. - 0.002 USDC per call.
- POST /v1/holidays - Retrieve public holiday dates and names for a specified country and year via Nager.Date, including whether each holiday is observed nationwide. - 0.002 USDC per call.
- POST /v1/knowledge/search - Search Wikidata for entities matching a free-text query and return normalized entity names, descriptions, and reference URLs. - 0.005 USDC per call.
- POST /v1/government/census - Query a constrained subset of US Census Bureau statistical datasets and return the requested variables as normalized rows for the specified geography. - 0.01 USDC per call.
- POST /v1/research - Aggregate information from selected Callrack research capabilities (academic, news, knowledge, and optionally government) and return structured research evidence with per-source status; deterministic composition, not an AI-generated answer. - 0.05 USDC per call.
- POST /v1/verify - Verify a claim against existing Callrack capabilities (academic, news, knowledge) and return a deterministic verdict - supported, contradicted, mixed, or insufficient - with the underlying evidence. Uses explainable lexical term-overlap and negation-cue heuristics, never an LLM or semantic entailment. - 0.05 USDC per call.
- POST /v1/evidence - Return a machine-readable evidence pack for a query - real results from academic, news, and knowledge search with full source provenance and retrieval timestamps, never an AI-generated narrative answer. - 0.05 USDC per call.
- POST /v1/compare - Compare information gathered from academic, news, and knowledge search for a query - distinct subjects, a flattened table of real attribute values, deduplicated sources, and any detected disagreements. Never fabricates a value a provider did not return. - 0.10 USDC per call.

Full request/response schemas: [OpenAPI](https://api.callrack.xyz/openapi.json) · [Interactive docs](https://api.callrack.xyz/docs)

## Notes
- Settlement is handled by the GoPlausible facilitator - you never pay Algorand network fees directly.
- An unpaid or invalidly-paid request never runs the underlying capability; you always get a clean 402 back.