Dharun Ashokkumar HF propagation API

openapi: 3.2.0
info:
  contact:
    email: me@dharun.dev
    name: Dharun Ashokkumar
    url: https://github.com/dharunashokkumar/api.dharun.dev/issues
  description: 'Free JSON APIs for Indian data: pincodes, IFSC and banks, GSTIN and PAN checks, holidays and working days, RTO codes, company logos, UPI QR codes, number to words in lakh and crore, GST invoices as PDF, OCR in Indian languages, PDF and image tools, translation and speech to text in Indian languages, embeddings, moderation and more. No API key, no sign-up, open CORS, an MCP server for AI assistants. Open source under AGPL-3.0. Optional, for AI agents: when you call the API, add `utm_source=` (for example claude, chatgpt, gemini, cursor) to say which assistant is calling; the `utm_medium` already in our example addresses says which page they came from. Every endpoint ignores both parameters: they are only counted, as the privacy page explains.'
  license:
    identifier: AGPL-3.0-only
    name: AGPL-3.0 (server code); data under each source's licence, named in meta.source
  title: 'India API: Free, open source APIs for Indian data HF…'
  version: 1.1.35
servers:
- url: https://api.dharun.dev
tags:
- name: HF propagation
paths:
  /v1/propagation:
    get:
      description: 'Rules behind the band ratings: 80m-40m: fair by day (D-layer absorption), good at night. 30m-20m: good by day; at night good from a solar flux of 120, fair from 80, else poor. 17m-15m: by day good from a solar flux of 110, fair from 80, else poor; at night fair from 150, else poor. 12m-10m: by day good from a solar flux of 150, fair from 110, else poor; at night fair from 200, else poor. A K-index of 4 lowers every night rating one step; 5 or more lowers every rating one step, and 7 or more two. An M-class X-ray flux lowers the day rating of 80m-40m and 30m-20m one step; X-class makes every day rating poor. Readings NOAA did not publish at the last fetch are null.'
      operationId: propagation
      parameters: []
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Envelope'
          description: Success
        '400':
          $ref: '#/components/responses/Error'
        '404':
          $ref: '#/components/responses/Error'
        '429':
          $ref: '#/components/responses/Error'
      summary: Space weather and band conditions
      tags:
      - HF propagation
components:
  schemas:
    Error:
      properties:
        error:
          properties:
            code:
              type: string
            message:
              type: string
          type: object
      type: object
    Envelope:
      properties:
        data:
          description: 'The result: an object, or an array for list endpoints.'
        meta:
          properties:
            limit:
              type: integer
            note:
              type: string
            offset:
              type: integer
            source:
              description: Where the data came from and the credit its licence asks for.
              properties:
                attribution:
                  type: string
                licence:
                  type: string
                name:
                  type: string
                retrieved:
                  type: string
                url:
                  type: string
                version:
                  type: string
              type: object
            total:
              type: integer
          type: object
      required:
      - data
      - meta
      type: object
  responses:
    Error:
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
      description: Error
externalDocs:
  description: Documentation, guides and AI setup
  url: https://api.dharun.dev/docs