navpipe 0.3.0

Unofficial Python SDK for fetching mutual fund NAV history from mfapi.in (Rust backend)

NavPipe

NavPipe is a high-performance, compiled Python SDK for fetching mutual fund NAV history from the unofficial API at:

👉 https://www.mfapi.in

By moving the core logic to Rust, NavPipe now offers massive concurrency with minimal overhead, returning results directly into Polars memory.

Why the Rust rewrite?

• 🦀 Safety: Memory-safe concurrent fetching using the tokio runtime.
• 🚀 Speed: Zero-copy data transfers between Rust and Python via pyo3-polars.
• 📊 Lazy-First: Native support for Polars LazyFrame, allowing you to optimize queries before they run.
• 🧵 True Parallelism: Bypasses the Python Global Interpreter Lock (GIL) for network I/O and data transformation.

---

Installation

pip install navpipe

---

Quick Start

import navpipe
import polars as pl

# Initialize the Rust-backed client
client = navpipe.NavPipe(max_concurrency=10)

# Eager execution: Returns a polars.DataFrame immediately
df = client.nav_history(
    scheme_codes=[119551, 120503],
    start_date="2023-01-01",
    end_date="2023-12-31",
)

print(df)

Output Schema

The Rust engine performs diagonal concatenation to ensure all scheme data is merged efficiently:

Column	Type	Description
scheme_code	Int64	The MFAPI unique identifier
date	Date	The NAV date
nav	Float64	The Net Asset Value

---

Important: Scheme Codes

NavPipe requires scheme codes to be provided manually. You can find these on: 👉 https://www.mfapi.in

Example: https://api.mfapi.in/mf/119551 → 119551 is the code.

---

Public API

NavPipe(max_concurrency: int)

Initializes the engine.

• max_concurrency: Limits the number of simultaneous HTTP requests using a tokio::sync::Semaphore.

nav_history(...) -> pl.DataFrame

Eagerly fetches and collects data into a standard Polars DataFrame.

---