z:za:ref
zaref / docs / bond-yields-api

South Africa government bond yields API

zaref serves the South African Reserve Bank closing yields on the government benchmark bonds as clean JSON. Two benchmarks are covered: the R2030, an 8 percent coupon maturing in 2030, and the R209, a 6.25 percent coupon maturing in 2036. Together they mark the short and long ends of the domestic yield curve.

Every response carries the coupon rate, maturity year and closing yield to maturity for each benchmark, the SARB timeseries code behind it (MMRD708A and MMRD709A), the reference date the yields closed on and the SARB source URL. Values are swept from the SARB WebIndicators API every South African business day, alongside the repo rate, ZARONIA and FX. If a publication is ever missed the response says so rather than serving a stale number silently.

Series

GET /v1/bond-yields

SARB closing yields on the R2030 and R209 South African government benchmark bonds, key reference points for the domestic yield curve.

$0.005 per call · updates: daily (SA business days) · effective 2026-08-13 · history at /v1/bond-yields/history ($0.01)

Calculators

GET /calc/bond-price

Clean price of a fixed-rate bond from face value, coupon and years to maturity, at a given yield (defaults to the live R2030 benchmark yield).

Parameters: face_value, coupon_percent, years_to_maturity, yield_percent, payments_per_year

$0.01 per call · example: /calc/bond-price?face_value=1000000&coupon_percent=8&years_to_maturity=4

How agents pay

No account, no API key. Paid endpoints reply HTTP 402 with exact payment requirements; an x402 client pays USDC on Base (about two seconds to settle) and retries automatically. Invalid input is rejected free with a 400 before any payment is challenged. See the x402 quickstart.

Questions

Which South African bonds does the API cover?
The R2030 and the R209, the two SARB benchmark bonds used as reference points for the domestic curve. Each returns its coupon percent, maturity year and closing yield percent, with the SARB timeseries code so the figure can be traced to source.
How often do the yields change?
SARB publishes closing yields every South African business day. zaref sweeps daily and stamps both the effective date of the yields and the date it last confirmed them, so a quiet weekend is never mistaken for a broken feed.
Does this mean a home loan bond?
No. In South African usage a bond usually means a mortgage, but this endpoint is government debt securities. For mortgage repayment maths use the bond-repayment calculator, which runs off the live prime rate.
Can I build a full South African rate curve from zaref?
Partly. zaref serves the SARB repo and prime rate, the ZARONIA overnight reference rate and these two benchmark bond yields, which covers the overnight, policy and long ends. It is not a full par curve: only the two SARB benchmarks are published, not every point on the term structure. The API says what it has rather than interpolating the rest.

Related

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