v0.1.0 — Initial Release

Changelog

All notable changes to nsefetch will be documented in this file.

The format follows Keep a Changelog.
This project adheres to Semantic Versioning.

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0.1.0 — 2026-05-15

Initial public release. 🎉

Added

Core Data Engine

• MarketService and AsyncMarketService — sync and async service facades with matching method signatures
• create_market_service(), create_cached_market_service(), create_production_market_service() — convenience constructors for all three runtime modes
• Equivalent async constructors: create_async_market_service(), create_async_cached_market_service(), create_async_production_market_service()

Market Data Methods (all 10 endpoints)

• get_nifty50() — NIFTY 50 index snapshot
• get_index(index_name) — any supported NSE index snapshot
• get_stock(symbol) — single-symbol equity quote
• get_bulk_stocks(symbols) — multi-symbol equity quotes with registry-guided batching
• get_option_chain(symbol, expiry=None) — option chain with nearest-expiry default
• get_option_chain_expiries(symbol) — discover all available expiry dates
• get_futures_data(symbol) — F&O futures snapshot
• get_delivery_data(symbol) — delivery / DPIIT data
• get_market_depth(symbol) — level-2 order book (optional data)
• get_sector_data() — all sector snapshots

Response Envelope

• ResponseEnvelope[T] — stable transport-agnostic metadata on every response: success, provider, request_id, fetched_at, stale, cache_hit, degraded, degraded_reason, warnings, data

Reliability Infrastructure

• Circuit breaker with configurable failure threshold and recovery window
• GCRA (Generic Cell Rate Algorithm) rate limiter — Redis-backed or in-memory
• Cache layer — Redis-backed or in-memory with per-operation TTLs
• Stale cache fallback — serves cached data on live fetch failure within degraded stale window
• In-flight request coalescing — deduplicates concurrent identical requests within a process
• Degraded state propagation — Redis / rate-limiter failures surfaced in response envelope

HTTP Transport

• NSEHttpClient / AsyncNSEHttpClient — curl_cffi-based browser-impersonating session with automatic cookie bootstrap
• Swappable transport boundary — pluggable live/test transport
• RetryPolicy — bounded exponential-backoff retries on transient failures

Tooling

• Live connectivity probe: python -m nsefetch.live_probe (transport-level)
• Service-level probe: python -m nsefetch.live_probe --service
• Combined: python -m nsefetch.live_probe --all
• Probe gated behind NSEFETCH_LIVE_PROBE_ENABLED=1 — safe to run in CI

Configuration

• Settings via pydantic-settings — all parameters configurable via environment variables with NSEFETCH_ prefix

Developer Experience

• 131 unit tests across 14 test modules (zero live-network calls in normal runs)
• Full Pydantic v2 typed schemas for all response data
• Context-manager support: with MarketService() as svc: / async with AsyncMarketService() as svc:
• Python 3.12+ with full type annotations

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