Cross-source API correlation connects runtime findings to their code, documentation, and fixes for improved defense against machine-speed attacks.
It's late on a Thursday, and a runtime alert fires on POST /api/v2/payments in production. The finding is clear. What happens next is not. In fact, it creates a host of questions to be answered:
- Which repository defines this endpoint?
- Is the endpoint documented anywhere?
- Is the staging version affected too?
- Who owns it?
Every AppSec team knows this hunt. And every day spent hunting for the right repo and owner is a day the attacker can still exploit a vulnerability.
Machine-speed exploits run through APIs
Finding vulnerabilities has become cheap, and turning them into working exploits is faster than ever. The Forum of Incident Response and Security Teams (FIRST) anticipates that more than 50,000 vulnerabilities will be discovered by the end of this year. AI helps attackers discover weaknesses and chain them together, so the list of findings keeps growing while the time to fix each one keeps shrinking.
Why patching API vulnerabilities takes so much time
Most of the time between an alert and a fix goes to figuring out where to apply that fix. Before patching, a security pro has to:
- Match the runtime finding to the right endpoint in the right codebase
- Find the repository that defines it
- Find who owns that repository and endpoint
- Check whether the API is documented, and whether staging or other environments share the flaw
- Get a ticket in front of the right team
Each step is a search in a different system, and those systems don't agree on what the API is called. And unfortunately, API discovery alone doesn’t solve that problem.
Companies can discover APIs from three sources, and each one was built for a different job:
- Live traffic (eBPF, API gateways, service meshes) shows what's actually running, with real requests, responses, authentication behavior, and runtime risk signals.
- Code repositories show where an API is defined, often before it is deployed or receives any traffic.
- Documentation (OpenAPI specs, Postman collections) shows what the API was designed to do, including the sensitive data it handles.
Each source is valuable, but each produces its own records. The same payments endpoint can show up three times in your inventory, once from code, once from docs, and once from live traffic. Determining that they are the same API is left to the security team that must contend with:
- Disconnected inventory. The same API appears as separate records, with nothing linking them.
- No lifecycle view. Security can't see how an API moves from design to code to staging to production.
- Slow remediation. Runtime findings aren't linked to the code behind them, which drives up mean time to detect and mean time to remediate.
- Blind spots. APIs that exist in code but never appear at runtime, or that run in production with no code or docs behind them, go unnoticed.
Having all of the information isn’t enough, it needs to be unified to simplify and speed patches.
Unified API Inventory: a correlated, single source of truth
Unified API Inventory, now generally available, correlates API discoveries across live traffic, code, and documentation. Discoveries that describe the same API are linked, and each keeps the details from its own source.
- Correlated across every source. Harness links live traffic with code repo, live traffic with documentation, and live traffic across environments. Your production payments API, for example, is linked to its staging twin too. An API doesn't need all three sources to be correlated. Any combination works, and a missing source is marked as not found.
- Code context on runtime APIs. A correlated runtime API shows the repository it comes from. The first question in the hunt "Where does this live?” is answered on the detail page.
- Gaps made visible. APIs found only in code or only in docs still appear in the inventory, labeled by source. Use the Discovery Sources filter to find APIs that are defined in code but not yet seen in traffic, or documented but never observed. These are often undeployed endpoints, or ones that bypass runtime collection.
For the AppSec engineer, that means fewer tabs and fewer Slack threads. For the CISO, it means one connected view of the API attack surface instead of three lists to reconcile. The end goal is simple: when an alert fires, the answer to "Where do I fix this?" is already on the screen. It allows security teams to reduce their time to patch and spend their time on more strategic work.
Harness customers can connect sources immediately
Unified API Inventory is available now as part of the API Posture capability in the Runtime Protection Agent. Connect your code repositories and upload your API specifications, and correlated sources will show up on the All Assets page alongside live traffic. To learn how correlation works and how to review an API's correlated sources, see the Unified API Inventory documentation.
Not a Harness customer yet? Reach out for a demo.
