This catalog tracks candidate runtime patterns that appear to recur across coding agents. Each pattern page should distinguish observed convergence from proposed standardization.
If this repository had to summarize the emerging pattern in one sentence, it would say this:
The most reusable coding-agent runtime looks like a guarded tool-result loop with explicit completion, recoverable failures, explicit runtime state, and policy boundaries around tool use and stopping.
The patterns that currently look closest to standardization are:
- tool-result loop,
- explicit completion action,
- recoverable tool errors,
- command-output streaming,
- a minimal state model that the UI can read without transcript parsing.
For a prose overview rather than a matrix, read synthesis/standardization-view.md.
| Pattern Or Capability | Roo Code | Cline | Claude Code | Copilot | Cursor | OpenHands | Confidence |
|---|---|---|---|---|---|---|---|
| Tool-result loop | Strong | Strong | Strong | Medium | Medium | Strong | High |
| Explicit completion action | Strong | Strong | Medium | Medium | Medium | Mixed | High |
| Guarded completion | Strong | Strong | Medium | Medium | Medium | Mixed | Medium |
| Recoverable tool errors | Strong | Strong | Strong | Medium | Medium | Strong | High |
| Separate runtime state machine | Strong | Medium | Medium | Strong | Strong | Medium | Medium |
| Context compaction | Medium | Medium | Strong | Medium | Medium | Medium | Medium |
| Resumability | Medium | Medium | Strong | Medium | Medium | Medium | Emerging |
| Bounded subagents | Medium | Strong | Strong | Medium | Medium | Mixed | Medium |
| Hooks and policy injection | Medium | Medium | Strong | Medium | Medium | Medium | Medium |
| Command-output streaming | Strong | Strong | Strong | Strong | Strong | Medium | High |
| Journal and telemetry events | Medium | Medium | Strong | Strong | Strong | Medium | Emerging |
- High-confidence convergence appears strongest around the loop itself, explicit completion semantics, recoverable failure handling, and streaming of tool activity.
- Medium-confidence convergence appears around state modeling, subagent bounds, hook insertion, and compaction behavior, where implementations differ but the need keeps recurring.
- Emerging patterns include explicit journaling contracts, resumability guarantees, and stop-hook validation as a reusable primitive.
- The repo treats these patterns as hypotheses to be refined through system reviews rather than as fixed doctrine.