MF NAV in the Wild. A Review of the API Logs, and How Widely the Mutual Fund NAV Data Is Being Pulled.
Published: September 7, 2026
I run a regular review of the API logs on Tigzig's mutual fund NAV API, covering security, errors and latencies. It is there to keep the service safe and to make it work better for the people using it.... and I was pleasantly surprised to see how widely this is being pulled ..
...from AI agents to spreadsheets to apps. Claude, ChatGPT, Google Sheets and Apps Script, Excel and Power Query, web apps and an iPhone app, crons and automated scripts, Zoho Deluge, n8n....
A fair part of it is plain Python, and also DuckDB querying the published Parquet file where it sits, without downloading it at all.
Many regular callers fill in the user agent that goes with each request...a short line naming the tool, what it is being pulled for, and often a project link or an email address. It's purely voluntary and self declared ... heartening to see that, and it makes the service much easier to run well.
The same review is what tells me what to improve. Several callers kept sending a parameter that did not exist, so I built it. A spreadsheet kept sending dates as plain numbers, so the error now spots that and says how to fix the cell. Memory and concurrency settings get tuned off what the traffic actually does. And so many people were pulling the latest NAV one scheme at a time that I published a single snapshot file carrying the whole scheme master.
Over the past week, more than 130,000 API calls and over 1,600 file downloads.
Docs
- For you: tigzig.com/apis/mf-nav
- For your agent: api.tigzig.com/mf/v1/openapi.json
A quick overview of what you can do with it
Three things. Search the schemes, pull NAV, or download the whole dataset.
- NAV can be pulled one scheme at a time or up to 50 in a single call, and you can ask for the full history, a date range, or just the latest value.
- The search API is how you find a scheme in the first place. Search by name, or filter and browse on the scheme master fields, AMC, category, plan, option, ISIN, active or matured, first and last NAV date.
- Downloads come in two shapes. The full history is 37.3 million rows covering every scheme back to April 2006, in Parquet, CSV, TSV or SQLite. The latest snapshot is one row per scheme, 38,194 of them, carrying the latest NAV along with the whole scheme master and the latest quarterly AUM. That one is 1.1 MB gzipped, so it is a quick way to get every current NAV at once.
One thing to keep in mind. All of it is at scheme level, meaning the plan and option variant. A single fund can have multiple rows, direct and regular, each with growth and IDCW, and sometimes more, so the scheme count runs well above the number of actual funds.
Live app with manual search, download, analytics, Data & API: tigzig.com/mfpro
SIF data
SIF data sits separately for now, at sif.tigzig.com. I am still working out how best to bring it into the main pipeline.
Working on something similar? How I work covers the rates, the availability and what I take on.