Sağlama — Source-Linked Participation-Finance Ratios
Live at saglama.com since July 2026: free, source-linked participation-finance ratios for companies listed on Borsa İstanbul. Each company record recomputes three ratios from the company's own financial statements and notes, and shows the numerator, denominator, threshold, date, method version and source document.
Inside Sağlama
Screens from the live Turkish site, captured in October 2026. Select any screen to open it at full size.
The Problem
Participation finance is Türkiye's name for Islamic finance. Investors who follow it need to know where a listed company stands, and how that was worked out.
Lists Lag Balance Sheets
The official participation list is updated at the start of each period, while company balance sheets change every quarter. A change between two updates reaches the official list only in the next period.
Numbers Need a Trail
A ratio is only useful if it can be checked: the numerator, the denominator, the threshold, the date, the method version and the document it came from.
More Than One Rulebook
The TKBB and Borsa İstanbul participation standard is the one in force. AAOIFI Shari'ah Standard No. 21 is calculated in parallel, so both have to be kept as exact, versioned rules.
What Was Built
A public site, a ratio engine and a data API, built solo and end to end.
Company Records
Three ratios per company (interest-bearing debt, interest-bearing assets and non-compliant income), recomputed from the company's own financial statements and notes. Each shows its numerator, denominator, threshold, date, method version and source document.
Rulebooks as Data
Rulebooks are kept as versioned data with quoted clauses: the TKBB and Borsa İstanbul participation standard in force, with AAOIFI Shari'ah Standard No. 21 calculated in parallel.
Index-Review Forecast
Published ahead of the October 2026 index review, then frozen and archived on 28 Sep 2026 for all 241 members. The list effective 1 Oct 2026 matched 238 of the 241 calls, and each miss is explained on the page.
Public Correction Log
Errors are fixed with a dated entry, never silently.
Beyond Single Stocks
Point-in-time history, a list of companies where the official index and the independent calculation disagree, pages for participation funds, sukuk, gold products and participation accounts, and a purification calculator.
Read-Only JSON API
In open preview. Every response carries the source, date and method version. Free for individual investors; institutions get API and bulk access.
Figures are as of October 2026 and come from the live site.
Engineering Highlights
Every figure has to survive a check against its source document.
- Provenance on every file — the Python data pipeline records a SHA-256 hash for every file it fetches.
- PDF statement parsing — figures are read from the companies' published financial statements and notes.
- Automatic recalculation — when a company publishes a new financial statement, its three ratios are recalculated.
- Measurements as ranges — a lower bound proven from the statements and notes, and a cautious upper bound.
- Rules generated from the engine's own files — the methodology page shows the threshold, formula, quoted clause, article and page the engine actually uses, with a version number.
- Point-in-time history — corrections are never deleted; they are published in a dated log.
- Frozen, archived forecasts — the October 2026 forecast was archived on the Internet Archive on 28 Sep 2026, before the result, and the graded result on 1 Oct 2026.
System Flow
+-----------------------------+
| Financial statements and |
| notes (PDF) |
+--------------+--------------+
| fetch + SHA-256
v
+-----------------------------+
| Python pipeline |
| - PDF parsing |
| - ratio engine |
| - versioned rulebooks |
+--------------+--------------+
|
v
+-----------------------------+
| PostgreSQL |
+--------------+--------------+
|
v
+-----------------------------+
| saglama.com |
| - public site (Next.js) |
| - read-only JSON API |
+-----------------------------+
Source, date and method version travel with every number
Technology Stack
Status
- July 2026 — work starts; saglama.com goes live on 17 Jul 2026 as a free public site.
- September 2026 — the site is indexed by Google; the October forecast is frozen and archived on 28 Sep 2026.
- 1 October 2026 — the new index list matches 238 of the 241 calls.
- Today — live; the institutional API is in open preview. Sağlama is a working name, and company formation is in progress.
Role: founder and sole developer. Savaş Tutumlu defined the method and publication rules, built the data pipeline, ratio engine, website, API and e-mail system, keeps the public correction log, and runs outreach to institutions.
Sağlama measures; it does not rule. It is not investment advice and not a religious ruling, and it has no affiliation with TKBB, AAOIFI, Borsa İstanbul or KAP.
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