Compact System Error Codes (Error Normalization & Token Pruning)

Overview

When a build fails or a test suite errors during an autonomous agent session, injecting a raw 80-line runtime stack trace (showing 40 frames of internal Node.js/Python library internals) burns 1,000+ tokens per failure turn.

Worse, repeating verbose stack traces across 3 retry attempts causes Error Fixation: the model gets trapped in an attention loop analyzing third-party library internals rather than fixing the 1-line root cause in the user's source code.

The Compact Error Code Protocol parses raw exception traces into standardized, single-line error tokens ([ERR_CODE: path/to/file:line - Root Cause Summary]), slashing token usage by 80% and pointing the model directly at the failure line.

80-Line Raw Stack Trace vs. Compact Error Token