Where do I get data for a fund due-diligence or fund selection tool?

What a fund due-diligence or selection tool needs from a data source

• Peer tables: the same metrics for every candidate, including active funds from smaller houses.
• Concentration, exposures and style facets to check a fund does what it says.
• Performance versus the stated benchmark, not versus a generic index.
• Costs at KID level, with reduction in yield.
• Change tracking between review cycles.

Why FundFacts API fits

profile.concentration, profile.valuation, profile.creditQuality and profile.rateSensitivity are derived with published thresholds, so "concentrated growth" means the same thing for every candidate. benchmarkName and the benchmark columns in every performance block make tracking-difference checks straightforward. investmentObjective is the KID text, quotable in the report. The Scale plan's GET /changes lists TER, risk-indicator, manager, benchmark, objective and top-five-holdings moves since any date, which is the review checklist itself.

What it does not do

• No qualitative research, ratings or manager interviews; those are the analyst's work or a vendor's.
• Holdings depth follows the fund house: full files for most ETFs, top ten for many active funds.

Start in ten minutes

1. Get a key at fundfactsapi.com/signup (Free plan, 15 lookups a month, no card).
2. Look up one fund and read the shape:

python
# pip install fundfacts   (or call https://fundfactsapi.com/api/v1/funds/{isin} with any HTTP client)
from fundfacts import FundFacts
​
ff = FundFacts()  # reads FUNDFACTS_API_KEY; free key at https://fundfactsapi.com/signup
fund = ff.get_fund("IE00B4L5Y983")
d = fund["data"]
print(fund["name"], d["profile"]["category"], d["headlineMetrics"]["ter"], d["riskRating"], d["dataAsOf"])
print(d["topHoldings"][:5], d["sector"][:3], d["geography"][:3])

1. Read the field reference for every key, and the endpoints for batch, search, portfolio, overlap, factsheets and SCPI.
2. If a coding agent is building it, point it at /llms-full.txt, the complete AGENTS.md for the API.

What it costs

A watchlist of 300 share classes refreshed daily is about 9,000 requests a month: Pro ($49), or Scale ($249) for the change feed. One request is counted per ISIN answered; search is free. Plans are on the pricing page.

Alternatives worth knowing

• Morningstar Direct or LSEG Lipper when ratings, analyst research and long histories are central to the process.
• Requesting data directly from managers via due-diligence questionnaires for private or non-public funds.

The provider comparison and the compare pages go into each in more depth.