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Cascade

Deep hub — prefer occam for the tool card (verified from code) and why-occam for framing. This page is a topic map + ADR pointer, not a second API.

Hub for the progressive-disclosure read path and how it relates to profiles. Deep contract: ADR-0017. Related: CAPABILITIES · TRUST · acquisition.

Cascade facade (occam)

MCP tool occam runs an ordered ladder and returns a step log (Tools/OccamCascadeTool.cs:15–25, Cascade/CascadeService.cs).

Order Stage (wire) Code Notes
1 playbook_resolve CascadeService.cs:119+ Always attempted; may omit on timeout
2 focus_budget :173+ Skipped when no task / budget
3 http_extract :212–245 HTTP extract
4 browser_fallback :247–296 Only if HTTP produced no body; else skipped (http_succeeded)
5 receipt :298+ Skipped when receipts disabled

Kinds / statuses: Cascade/CascadeModels.cs:4–30 (ok, skipped, omitted, failed, degraded).

flowchart TD
  A[playbook_resolve] --> B[focus_budget]
  B --> C[http_extract]
  C -->|ok body| E[receipt]
  C -->|no body| D[browser_fallback]
  D --> E

Not cascade stages

Concern Where it lives Why separate
Static / rotating proxy Workers/EgressProxyConfig.cs, RoundRobinProxyRotationService.cs Applied on worker spawn, not a CascadeStepKind
External CLI (External CLI, OCR helpers) External/ExternalCli.cs Optional binaries; not fetch ladder steps

Do not draw proxy or external as cascade stages in diagrams or agent prompts.

Cascade vs Router

Path Mechanism Code
Facade tool occam Explicit stages + step log CascadeService.cs
occam_transcode / digest / … with backend_policy=http_then_browser Router HTTP→browser escalate Routing/OccamRouter.cs:33+

Same backends; different surfaces. Prefer occam for progressive disclosure; use occam_transcode when you need the full opt-in parameter set (tools/occam_transcode).

Capability exam → profile (beta)

Exam is a CLI grader (Exam/ExamCliVerbs.cs, ExamGradeCli.cs), not an MCP tool and not an automatic profile switch.

Score Tier Recommended OCCAM_PROFILE Tools
0–1 Weak minimal 1
2–3 Medium basic 3
4 Strong full 16 core

Source: Exam/ExamScoring.cs:33–51, ExamCliVerbs.cs:153–156. Tasks: Canary, BasicCall, FocusBudget, Chain (ExamTasks.cs). ADR: 0016-capability-exam.

Operator applies the result by setting OCCAM_PROFILE. There is no “auto-adaptive MCP” runtime.

Documented profiles for this hub: minimal / basic / reader / full (Transport/OccamToolProfile.cs). Default process profile without exam: reader (11 tools).