Choosing a broker API for algo trading in India: start with the job

The criteria used in this decision guide

• Required function

  Specify the archive, order function or chain response. A documented endpoint matters more than a general automation headline.

• Data identity and limits

  Name the instrument, interval and expiry, and distinguish a request cap from the available archive. This matters even when the subscription is free.

• Access and operating routine

  Check the login flow, session boundary, permitted hosting and network requirements. Compare the actual interface you will run.

• Cost at the intended activity

  Count executed orders separately from data requests. State the subscription tier, tax basis, billing cycle and offer expiry.

• Evidence and recovery

  Look for enough documentation to reconcile submitted orders, returned status and the account record. We grade no broker's reliability because no controlled execution test was performed.

Follow the branch that matches the program's main task

1. 1

   Archive first: a data-heavy backtester

   Check the required dates, candle interval and expired-contract identity before the order API. Upstox v3, for example, documents minute/hour history from January 2022 and daily/week/month history from January 2000. Those different starts matter to a research specification; they do not establish complete observations for every instrument. Use the historical-data guide for the full archive comparison.

2. 2

   Orders first: an occasional executor

   If the program already has an appropriate data source, examine the trading-only tier and login/network requirements. Kite Personal is free for account/order functions and excludes live/history data. Paying for Connect solves a data-access requirement; it does not improve a rule merely because money was spent. Keep the chosen data source's permitted-use conditions in the specification.

3. 3

   Chain first: an options-data reader

   Ask for expiry selection, open interest, implied volatility and the fields actually returned. Dhan's chain docs list these fields and throttle the same unique request to one every three seconds, while allowing different underlying/expiry requests concurrently. That is a request condition, not measured refresh delay. A quote stream and a whole-chain response are different interfaces.

4. 4

   Platform first: a webhook or hosted workflow

   Identify who runs the logic, receives the instruction and sends the order. Then check the broker's supported arrangement and the relevant registration/hosting requirements. A webhook's arrival alone does not establish that the broker accepted or executed an order. Do not give a platform account rights merely because its website displays a broker logo.

Cost components at 0, 50 and 500 executed option orders

Checked 14 October 2026. Assumed existing resident retail account; one charged subscription cycle. Brokerage figures are before GST. Data quotes retain their stated tax basis. No final tax-inclusive trading bill or activity recommendation is implied.

Brokerage = assumed executed orders × stated option rate: ₹20 gives ₹0/₹1,000/₹10,000; ₹10 gives ₹0/₹500/₹5,000; ₹5 gives ₹0/₹250/₹2,500. Data/API fees are sourced separately from brokerage. Excludes transaction taxes, clearing/account/RMS/dealer fees, server/static-IP costs and paid platform fees. Dhan's 30-day cycle is not a promise of one debit in every calendar month. No lot sizes, premiums or traded quantities are assumed.

Operating details that can change a shortlist

Primary documentation checked 14 October 2026. Selected details, not a full implementation or regulatory matrix; no authentication or order-placement test.

Token lifetime is from Kite's user docs, network scope from Zerodha support. Other rows use each provider's own authentication/notice/prerequisite documentation. The regulatory workflow is linked below instead of reconstructing the full rules here.

An acceptance checklist for the shortlisted interface

• One representative data requirement

  Specify an instrument, date range, interval and expiry without choosing it for expected profit. Verify the entitlement and returned identity. Shoonya's cited history page documents daily end-of-day candles; it does not establish a deep intraday archive.

• Request units and conflicts

  Dhan's v2 order table gives 10 requests per second and 7,000 daily, while its product page lists 25 orders per second and 5,000 daily. Preserve that conflict and obtain the applicable limit; do not assign the larger figures a performance score.

• Recovery after an uncertain result

  Define how submitted instructions will be matched to broker order status and the final trade record. A timeout does not tell the trader whether an order exists. Test only within an authorised setup and document the recovery outcome.

• A dated cost record

  Keep the actual subscription debit, invoice, offer conditions and executed-order count together. The illustrative table is a starting specification, rather than a replacement for the account's bills.