Where our numbers come from
Every source we use, what it feeds, and — just as important — what we deliberately do not use.
Last updated 25 July 2026
A tool that tells you what to do with your money owes you a straight answer about where its numbers came from. This page is that answer. It also lists sources we evaluated and rejected, because “we could have used this but chose not to” is information too.
Feeds: Bond prospectuses, auction results, T-bill rates, exchange rates, reserves, and the full Central Bank Rate history since 2008
The primary authority for everything we compute. Published as public PDFs and tables. Every rate decision we chart links back to the MPC press release it came from, so you can check us against the original.
Feeds: Monthly CPI / inflation
Needed to state real (after-inflation) yields rather than nominal ones.
Feeds: GDP growth and structural indicators
Free, keyless, versioned JSON API under CC BY 4.0 — the only major source on our list we may lawfully redistribute.
Feeds: Public debt stock and debt-to-GDP
The debt burden is the single best indicator of whether yields stay high — and whether they are sustainable.
Feeds: Linked only — we are not permitted to republish it
Two separate blocks, verified July 2026. The free Daily Bond Price List is published as scanned images with no text layer, so software cannot read it, and we will not OCR it — a misread digit in a bond price is a wrong number stated with full confidence. More decisively, the NSE Data Services terms state their data is proprietary, may not be copied, stored or distributed, and may not be used to develop a product, except for your own personal use. We respect that. Look up a price there yourself and enter it in our calculator — that is personal use, and it stays on your device.
Feeds: Debt sustainability analysis, Article IV projections
Cited for context in our figures; the reports themselves are worth reading in full at source.
Feeds: Cross-checking our figures during development
Copyrighted research. We read it, we do not republish it, and we do not present anyone else’s analysis as ours.
Feeds: Auction results before the official PDF is indexed
Useful for timeliness, always superseded by the CBK original once available.
Feeds: Background reading on Kenyan public finance
Kenya’s public-policy research institute publishes genuinely useful analysis — the Kenya Economic Report and similar. It is prose and PDFs rather than structured data, and it is all rights reserved, so we cite and link rather than ingest.
The API requires a key, and this app ships as static files with no server to hold one. Redistribution also sits outside their terms.
Unofficial or scraping-restricted endpoints. We will not build a money tool on an interface that can vanish or that we are not permitted to use.
A paid subscription service. Their Kenya page did not resolve when probed, and even if it had, redistributing licensed bond data in a free public app is not something a subscription permits.
Returns HTTP 403 to automated requests, and its focus is listed-company financial statements rather than government bond pricing. Neither permitted nor particularly relevant to what we compute.
Blocks automated access and licenses its market data commercially at terminal prices. Excellent journalism, entirely unavailable to a free app — and republishing it would be straightforwardly unlawful.
Data is available to market participants only. Your holdings stay between you and your CSD account.
Why so much is “linked, not copied”
Mwangaza Yield is a static application: it has no server, so it can hold no API keys and run no private queries. That rules out every paid or authenticated feed. It also means we cannot lawfully mirror licensed market data or copyrighted research. Rather than pretend otherwise, we compute everything we can from public primary sources and send you to the original for the rest.
The upside of that constraint is real: no key means no server, no server means no account, and no account means your portfolio never leaves your device.
Freshness and honesty
- Auction results and rates carry the date of the auction they came from.
- The rate-cycle chart compares today against the level the current cycle started from, not the 2011 record high. Measuring against the record would show a fall that never happened as a single move.
- Coupon dates are estimated from issue schedules and are labelled as estimates wherever they appear.
- Yields without a published auction print are interpolated from the prevailing curve, and say so.
- When the app is offline it shows a badge, so a cached figure is never mistaken for a live one.
Spotted a figure that disagrees with the official source? That is the most valuable bug you can report — see Support.
Attribution
World Bank Open Data is used under CC BY 4.0 . CBK, KNBS, National Treasury and NSE materials remain the property of their publishers and are used for information with attribution.