Environment & Operations › Disciplines & the boundary
Disciplines & the boundary
Business-blind, model-agnostic, future-proofed, self-optimizing. The acceptance test: if the person operating this
layer has to ask “what does PE mean?”, the layering has failed. In the seven-layer model, Intelligence (L4), Integration (L5) and Data & Documents (L6) are drawn as their own layers but their machinery, including BOTH MCP boundaries (north platform gateway, south tool servers), is operated from here: Intelligence and Integration by harness engineering, Data by platform engineering.
Full spec: pe-solution-layer/docs/ENVIRONMENT_LAYER.md.
The two disciplines & the boundary
H Harness engineering
Everything that executes per agent run: the agent loop and run-contract enforcement, tool dispatch and MCP machinery, model routing, context assembly and compaction, memory, sandboxing, guardrail enforcement, verification runners, trace and eval infrastructure.
P Platform engineering
Everything that exists before and around runs: cloud accounts and networking, identity and tenancy provisioning, CI/CD and repo scaffolding, secrets and keys, data-pipeline plumbing, storage lifecycle, SRE operations, release mechanics.
Boundary rules:
- The dividing line is the agent run. Anything that executes during a run belongs to harness engineering; anything provisioned or operated around runs belongs to platform engineering.
- The environment builds configuration slots and never fills them. Which tools an agent sees comes from the plane; context-pack contents come from Knowledge; loop end states come from run contracts; gates and approvers come from the plane.
- Both halves stay business-blind. The business-blindness linter in CI enforces this on every commit.
- Five things that look like environment work but belong elsewhere. Eval rubrics and golden exemplars belong to Knowledge; the glossary belongs to the Knowledge docs; gate definitions belong to the plane; the authority ranking belongs to Knowledge; context-pack contents belong to Knowledge.