The way market data reaches traders, analysts and apps in India has changed a lot in the last decade. What started as raw exchange feeds and file dumps has become a rich set of APIs that power mobile apps, algorithmic strategies, back-office systems and retail investor dashboards. This article explains that evolution in simple terms and what it means for firms and developers in India.
Early days: files, sockets and proprietary feeds
In the past, market data was often delivered as end-of-day files or proprietary binary streams. Many brokers and trading firms used direct exchange feeds from NSE, BSE or MCX. These feeds were high volume and required specialised infrastructure to parse, store and distribute. Small teams needed expensive hardware and low-latency networks to keep up. Access costs could be high and distribution rules from exchanges and SEBI added complexity.
REST and the arrival of simple APIs
As web technologies matured, RESTful APIs became popular. REST APIs provided easy snapshot requests for prices, historical candles and basic market information. Startups could now request data over HTTPS from cloud vendors and integrate it into dashboards without custom parsing code. For Indian fintechs, this lowered the barrier to entry: retail apps, advisory platforms and new brokerages could build products faster.
Streaming and real-time needs
Real-time trading and algorithmic strategies demanded streaming APIs. WebSocket and server-sent events allowed continuous price updates suitable for trader screens and live charts. For low-latency trading, vendors offered specialised sockets, multicast feeds or FIX-based market data. The result: firms could choose the right level of latency and reliability for their use case, from retail apps to HFT desks.
Modern protocols and standardisation
Newer protocols like gRPC and binary transports improved efficiency for high-throughput needs. Vendors and data platforms began normalising data formats so the same API could serve equities, derivatives and commodity feeds. Standard schemas reduce integration time — a single API call can return exchange-agnostic price, volume and instrument metadata rather than different shapes for each exchange.
Cloud-native delivery and pay-as-you-use pricing
Market data moved to the cloud, making scaling easier and costs more predictable. Instead of upfront hardware investment, teams can subscribe to cloud APIs and scale usage. This helped Indian startups because they could start with smaller monthly spend and grow. Pricing models now include per-call billing, tiered subscriptions and enterprise contracts, allowing both small advisors and large brokers to pick what suits them.
Data as a product: enrichment and analytics
APIs no longer just deliver raw ticks. Many providers add derived data: computed indicators, adjusted historicals, corporate action handling and sentiment tags. These enriched APIs save developers from reprocessing raw data and make product development faster. For retail apps in India, this means built-in support for things like split-adjusted price history and index composition updates.
Regulatory and compliance considerations
In India, distribution of exchange data must follow SEBI and exchange licensing rules. API users need to be aware of redistribution limits, display obligations and audit trails. Mature API vendors provide compliance tools, logging and contract-friendly licenses so businesses can operate without breaching rules.
Where to choose between REST, WebSocket, FIX or vendor SDKs
Best practices for Indian teams
Note on costs and access
Smaller firms can start with affordable API tiers and scale as their user base grows. Large trading desks still invest in direct feeds and co-location for the lowest possible latency, while many retail-facing companies use cloud APIs to balance cost and reliability.
In short, the evolution from files and proprietary streams to modern, cloud-native APIs has made market data easier to use and integrate. Choosing the right API type, understanding compliance, and using enrichment wisely are the keys to building successful market data products in the Indian context.
Early days: files, sockets and proprietary feeds
In the past, market data was often delivered as end-of-day files or proprietary binary streams. Many brokers and trading firms used direct exchange feeds from NSE, BSE or MCX. These feeds were high volume and required specialised infrastructure to parse, store and distribute. Small teams needed expensive hardware and low-latency networks to keep up. Access costs could be high and distribution rules from exchanges and SEBI added complexity.
REST and the arrival of simple APIs
As web technologies matured, RESTful APIs became popular. REST APIs provided easy snapshot requests for prices, historical candles and basic market information. Startups could now request data over HTTPS from cloud vendors and integrate it into dashboards without custom parsing code. For Indian fintechs, this lowered the barrier to entry: retail apps, advisory platforms and new brokerages could build products faster.
Streaming and real-time needs
Real-time trading and algorithmic strategies demanded streaming APIs. WebSocket and server-sent events allowed continuous price updates suitable for trader screens and live charts. For low-latency trading, vendors offered specialised sockets, multicast feeds or FIX-based market data. The result: firms could choose the right level of latency and reliability for their use case, from retail apps to HFT desks.
Modern protocols and standardisation
Newer protocols like gRPC and binary transports improved efficiency for high-throughput needs. Vendors and data platforms began normalising data formats so the same API could serve equities, derivatives and commodity feeds. Standard schemas reduce integration time — a single API call can return exchange-agnostic price, volume and instrument metadata rather than different shapes for each exchange.
Cloud-native delivery and pay-as-you-use pricing
Market data moved to the cloud, making scaling easier and costs more predictable. Instead of upfront hardware investment, teams can subscribe to cloud APIs and scale usage. This helped Indian startups because they could start with smaller monthly spend and grow. Pricing models now include per-call billing, tiered subscriptions and enterprise contracts, allowing both small advisors and large brokers to pick what suits them.
Data as a product: enrichment and analytics
APIs no longer just deliver raw ticks. Many providers add derived data: computed indicators, adjusted historicals, corporate action handling and sentiment tags. These enriched APIs save developers from reprocessing raw data and make product development faster. For retail apps in India, this means built-in support for things like split-adjusted price history and index composition updates.
Regulatory and compliance considerations
In India, distribution of exchange data must follow SEBI and exchange licensing rules. API users need to be aware of redistribution limits, display obligations and audit trails. Mature API vendors provide compliance tools, logging and contract-friendly licenses so businesses can operate without breaching rules.
Where to choose between REST, WebSocket, FIX or vendor SDKs
- REST — best for snapshots, historical data and simple APIs that work over HTTPS.
- WebSocket — suited for live updates on prices and order book changes for trading screens and mobile apps.
- FIX / proprietary sockets — used by low-latency trading firms and brokers needing reliable order routing and market data.
- gRPC/Streaming binary — useful for high-throughput systems where efficiency and schema contracts matter.
Best practices for Indian teams
- Cache frequently requested data to reduce costs and improve responsiveness.
- Use normalised schemas to keep multi-exchange integration simple.
- Plan for compliance: track subscriptions, logs and redistribution terms.
- Test latency and resilience — simulate market bursts to see how APIs behave during volatility.
Note on costs and access
Smaller firms can start with affordable API tiers and scale as their user base grows. Large trading desks still invest in direct feeds and co-location for the lowest possible latency, while many retail-facing companies use cloud APIs to balance cost and reliability.
In short, the evolution from files and proprietary streams to modern, cloud-native APIs has made market data easier to use and integrate. Choosing the right API type, understanding compliance, and using enrichment wisely are the keys to building successful market data products in the Indian context.