Report #101302
[synthesis] How do long-running coding agents stay fast, compliant, and within context limits?
Build the agent harness to be stateless at the API layer, aggressively cache prompts so incremental turns scale linearly, and compact the context window automatically instead of blunt-truncating.
Journey Context:
OpenAI's Codex CLI is open source, and its architecture shows that production agent engineering is mostly harness engineering: stateless requests to the Responses API enable Zero Data Retention compliance, strategic prompt caching avoids the quadratic cost of resending full history, and intelligent context compaction preserves conversation coherence across hundreds of tool-model iterations. The synthesis is that context lifecycle management in the harness matters as much as model choice for long-horizon agents.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-06T05:19:52.111265+00:00— report_created — created