# What is an evidence level in Provely?

> The rank of a piece of evidence by its independence from the action path, E0 to E5. The Provely definition, with an example.

Canonical: https://provely.sh/glossary/evidence-level  
Last reviewed: 2026-09-05  

**An evidence level ranks evidence by how independent it is from the action path. E0 is the agent word and is never sufficient. E5 is an external outcome, such as a bank credit. The table states each level.**

| Level | Source | Proves |
| --- | --- | --- |
| E0 | Agent assertion | Nothing. Never sufficient. |
| E1 | Action response | Acknowledgement. Rarely completion. |
| E2 | Provider readback | Deterministic state, subject to stale reads. |
| E3 | Provider event | Strong timing. Needs deduplication and ordering. |
| E4 | Independent system | The provider plus your own ledger agree. |
| E5 | External outcome | A bank, a carrier, or a recipient acknowledged. |

## Read next

- [Read the definition of Acknowledgement](https://provely.sh/glossary/acknowledgement)
- [Read the definition of Verdict](https://provely.sh/glossary/verdict)
- [See every glossary term](https://provely.sh/glossary)
- [Read how Provely works](https://provely.sh/how-it-works)