Mutual fund portfolio API: AMFI holdings as JSON

A mutual fund portfolio API turns the monthly scheme portfolio files that every Indian AMC publishes into structured data you can query, rather than a folder of spreadsheets you have to open one by one. The disclosure itself is public and free, published on the AMC's website and on AMFI's. What an API adds is identity resolution across schemes and securities, history you can query as a time series, and the period end date carried on every row so staleness travels with the data. This page sets out what such an API should return and what it cannot. It is not investment advice.

What should a mutual fund portfolio API return?

The prescribed source format has four columns: name of the instrument, quantity, market value in lakhs of rupees, and percentage to NAV, with a rating line inside the debt sub groups. A usable API carries those, plus the things the source file expresses structurally rather than as columns:

• Scheme identity, since each file is published per scheme and the scheme is the record's subject.
• ISIN, required by Paragraph 6.1.1 as part of the disclosure but not a column of the prescribed format, which is exactly why it needs to be normalised rather than assumed.
• Instrument sub group, because equity listed, equity unlisted, debt listed, privately placed debt, securitized debt, money market and interest rate derivatives are conveyed by headings in the file.
• Market value with an explicit unit, since the source column is in lakhs of rupees.
• The marks, since an asterisk can mean a weight below 0.01 percent of NAV, a debt instrument below investment grade or in default, or an illiquid security, and a double asterisk means thinly traded, non traded or illiquid.
• The period end date and the cadence, monthly or fortnightly, so a fortnight end row is never read as a month end one.

Why parsing is the hard part

Because the meaning of a row is not in the row. It is in the heading above it, the mark beside it and the footnote below it.

Scale. Reading the market value column as rupees rather than lakhs of rupees overstates every holding by a factor of one hundred thousand. This is the single most consequential parsing error in the dataset, and it is silent: the numbers still look plausible in relative terms.

Sub group. Two rows with identical columns mean different things depending on whether they sit under equity listed or equity unlisted. An unlisted holding has no exchange price behind it and no company side counterpart to cross check against.

Order. The entire portfolio is disclosed in descending order of weightage within each sub group, so the ordering resets at every heading. A naive top N taken across the whole file is not the scheme's largest holdings.

Footnotes. Portfolio turnover ratio for equity schemes, average maturity for debt schemes, NAV at the beginning and end of the month, total illiquid equity, total derivative exposure, total foreign securities, and the count of valuation deviations with a link. These are real fields living outside the table. The full walkthrough is in how to read a mutual fund portfolio statement.

What an API over this data cannot do

It cannot make the data live. Every figure is a period end position published after the period closed, under Paragraph 6.1.1's 10 calendar day monthly deadline or the 5 calendar day fortnightly deadline for debt schemes. A scheme may have traded on the day after the period end and nothing in the file will show it.

It cannot reconcile row for row against company side ownership records either. Those run quarterly, in percentages of total shares, filed by the company rather than the AMC. That difference is worked through in AMFI portfolio data vs shareholding pattern.

And it cannot tell you what a holding means. The record is what was held, in what quantity, at what weight, on a stated date.

How Flock exposes it

Flock ingests Indian mutual fund scheme holdings alongside company side shareholding pattern data and US 13F filings, resolves securities to a stable identity across sources, and keeps the filing or period end date on every row so staleness is queryable rather than assumed. The same holdings power the fund views described in mutual fund portfolio tracker India.

If you want the underlying obligation rather than the API shape, start with what is a monthly portfolio disclosure.