Context Planes
Context Planes
Section titled “Context Planes”Context planes classify where information originates and how much trust it carries. Every piece of context consumed or produced during a workflow step must be tagged with its plane.
Plane A — Local Verified
Section titled “Plane A — Local Verified”Information that exists inside this repository and has been directly read or verified during the current session.
| Property | Value |
|---|---|
| Trust | High |
| Examples | Source files, test results, CRUMBLOG entries, build output |
| Verification | File read + path confirmed |
| CRUMBLOG tag | PLANE:A |
Rule: Plane A claims require a repo path and line number as evidence.
Plane B — External Referenced
Section titled “Plane B — External Referenced”Information fetched from outside the repo during the session — documentation sites, API specs, MCP server responses, web searches.
| Property | Value |
|---|---|
| Trust | Medium |
| Examples | Library docs, MCP tool output, web search results, Context7 query results |
| Verification | URL or tool invocation logged |
| CRUMBLOG tag | PLANE:B |
Rule: Plane B claims must include the source URL or MCP tool name. If the source is ephemeral (e.g., a web search), note the query and date.
Plane C — Assumed / Inferred
Section titled “Plane C — Assumed / Inferred”Information not directly verified — prior knowledge, assumptions, inferences from partial data.
| Property | Value |
|---|---|
| Trust | Low |
| Examples | ”This library probably supports X”, model knowledge, cross-session memory |
| Verification | None — must be upgraded to A or B before implementation |
| CRUMBLOG tag | PLANE:C |
Rule: Plane C claims must include a RISK: tag. They cannot be used as the sole basis for implementation decisions. They must be verified (promoted to A or B) before code is written.
Plane Promotion Rules
Section titled “Plane Promotion Rules”- C → B: Fetch the external source and confirm. Tag with URL/tool.
- C → A: Find the evidence in the repo. Tag with path:line.
- B → A: Confirm the external claim matches repo state. Tag with path:line.
Conflict Resolution
Section titled “Conflict Resolution”When claims from different planes contradict:
- A beats B beats C — local verified truth wins.
- If two Plane A claims conflict, the more recent file modification wins. Log both in CRUMBLOG with
RISK:conflict. - If a Plane B claim contradicts Plane A, the external source may be outdated. Flag in CRUMBLOG, do not silently adopt the external claim.
Dataflow Classification
Section titled “Dataflow Classification”Any new dataflow (data entering or leaving the system) must be classified before implementation:
| Dataflow | Plane | Action Required |
|---|---|---|
| API request body (validated by Zod) | A (after validation) | Validate per GUARDRAILS |
| WebSocket message from client | A (after validation) | Validate before processing |
| MCP tool response | B | Log tool + query, verify before trusting |
| Web fetch content | B | Log URL + date |
| LLM inference | C | Tag RISK, verify before implementing |
| Cross-session context | C | Re-verify in current session |
| External agent SEMP event | B | Log agent_id + trace_id, validate schema |