SLOs on Public APIs

Public APIs: must publish SLA matching SLO.

Publish

The moment an API is exposed to external consumers (paying customers, partner integrations, public developer docs), the SLO stops being an internal engineering tool and becomes a public commitment. The only question is whether you publish it deliberately or whether your customers reverse-engineer it from your incident pattern. Deliberate is better.

What "published" actually means:

• SLA on the public docs.: A page customers can find without an account, written in plain language, that says exactly what reliability the API commits to. Availability target, latency target, the measurement window, and the credit policy if you miss. Vague phrasing here invites lawsuits later.
• Live status page.: A separate, always-up surface (status.yourcompany.com is the convention) showing current availability, ongoing incidents, and the rolling SLO performance. Hosted on infrastructure separate from the API itself so it stays up when the API does not.
• Contract terms in the customer agreement.: The SLA referenced in the docs is incorporated by reference into the master service agreement. Legal will need to be in this conversation. Do not negotiate SLA language at the engineering layer alone.
• Version-pinned commitments.: The SLA covers specific API versions. v1 has a different commitment than v2-beta. The status page distinguishes them. Customers integrating against beta endpoints know they are doing so without the production SLA.

Publishing the SLO is not a marketing decision. It is the contract that tells procurement and security teams whether they can buy the API at all. Most enterprise sales cycles fail or accelerate based on what is on this page.

Track public

Once the SLA is public, the measurement of it must be too. The mechanism that prevents this from being marketing-driven theater is honest, public reporting against the published target.

• Quarterly performance report.: Every quarter, publish the actual SLO achievement against the published target. "Q3 2026: 99.94% availability against a 99.9% target" or "Q3 2026: 99.86% against a 99.9% target, missed by 0.04 percentage points, see incident summary." Both formats are required reading.
• Incident-level disclosure.: Every customer-impacting incident gets a public RFO (reason for outage) on the status page within 5 business days. Duration, scope, root cause, what changed to prevent recurrence. Specific. Concrete. Timely.
• Methodology disclosure.: Customers should be able to compute the SLO themselves from the published metric definitions and time windows. If your "availability" is calculated using a methodology nobody else can reproduce, the number is not trustworthy.
• Don't game the window.: The temptation when a quarter is going badly is to redefine the SLO at the last minute, exclude an incident as "out of scope," or move to a longer averaging window that hides the bad month. Resist it. Customers will notice and the trust hit is permanent.

Public tracking is what separates a published SLA from a published wish. The teams that do this well treat the report as a regular product release, not a compliance exercise.

Brand

The compounding return on a serious public SLO practice is not technical. It is reputational. Reliable APIs become the API category leader, sometimes regardless of features.

• Reliability is the moat in commodity API markets.: Once an API category has more than two viable vendors, the technical features converge. The vendor that consistently posts higher real availability over multi-year windows wins enterprise sales because procurement decisions are made on uptime evidence, not feature parity.
• Customers stop second-guessing the dependency.: When your published SLA has been hit for 11 of 12 trailing months, customer architects stop building elaborate fallback paths around your API. They trust it, which lets them build more on it, which makes the relationship stickier.
• Engineering recruiting follows.: Senior engineers actively pick employers based on operational rigor signals. A public SLA with honest tracking is one of the strongest such signals. Talented operators want to work on systems that are taken seriously.
• Negative compounding goes the other way.: A vendor with three bad quarters in a row, blamed on increasingly specific external causes, loses trust permanently. The brand damage from public SLO failures is much harder to recover from than the same outages would be if they were never advertised against a target.

A public API SLO is the highest-leverage operational commitment a company can make. It costs nothing to publish and it pays for itself for years if you keep it. Nova AI Ops produces the per-quarter SLO performance numbers, the rolling status page feed, and the incident-level RFO drafts, so the operational work of running the SLA is automated and the storytelling work of publishing it is the only piece left for humans.