COG Loop Engineering

TL;DR: Some COG skills are not one-shot prompts. They are loops: act, observe, verify, decide whether to continue. This skill is the shared vocabulary those skills use. The iron rule: trust deterministic checks, never the agent's own "looks done" self-report. Every loop must declare its verifier, its stopping conditions, and which pattern it follows.

This is a reference and design aid, not a content-generating workflow. Skills that loop (daily-brief, knowledge-consolidation, url-dump, weekly-checkin, and research/triage skills like auto-research and scout) link here instead of restating the rules. Invoke it directly when you are building or fixing an iterative skill.

Why loops

A chain runs fixed steps: A then B then C. A loop is dynamic: the agent takes an action, reads real feedback (a fetched page, a date stamp, a file count), reasons about it, and repeats until a goal is met or a stop condition fires. Most knowledge-work that "keeps going until good enough" is a loop, and COG benefits from naming the loop explicitly rather than hoping a single prompt nails it.

The COG loop

   ┌──────────────────────────────────────────────┐
   │  1. Gather    pull context (vault + sources)   │
   │  2. Act       one step: search / fetch / scan  │
   │  3. Observe   read the real result             │
   │  4. Verify    run the deterministic check      │
   │  5. Update    write progress to a vault file   │
   │  6. Decide    continue?  → loop                │
   │               stop?      → finish + report     │
   └──────────────────────────────────────────────┘

Step 4 is the load-bearing one. A loop without a verifier is just a chain that repeats.

Termination conditions (use layers, never one)

A robust loop needs several exits so it always halts:

Exit	What it is	Example
Deterministic verifier	A mechanical pass/fail that confirms the goal	"Publication date is within 7 days"
Hard iteration cap	Max passes, no matter what	"Stop after 5 searches per topic"
Budget guard	Max time / tool calls / tokens	"Stop after 20 fetches total"
No-progress detection	Recent passes changed nothing	"2 searches in a row found nothing new"
Human escalation	Hand a stuck loop back to the user	"Asked twice, still unclear: ask the user"

Pick the verifier plus at least one safety exit (cap or budget) for every loop. No-progress detection is what stops the quiet infinite loops that a cap alone misses.

Verification first (COG's rule, applied to loops)

COG is verification-first: no hallucinations, sources required. Inside a loop that means:

• Prefer mechanical checks. A date comparison, a source count, a "required field is non-empty", a "file marked consolidated" check cannot be gamed and cannot be hallucinated.
• Reserve judgment-based checks for the genuinely unquantifiable (is this theme actually new? is this summary faithful?). When you must use judgment, state confidence and link evidence.
• Never accept the agent's own "I think this is complete." That is the single most common way loops produce confident garbage.

In-loop context management

Long loops fill the window with old tool output and start to drift ("context rot"). Counter it:

• Externalize state to the vault. Write progress to the output file as you go. The vault file is the memory; the conversation is scratch.
• Compact and prune. Summarize finished passes into a line or two. Drop raw page text once you have extracted what you need.
• Isolate sub-agents. In agent_mode: team, give each worker only the slice it needs and take back only its conclusion, so one subtask runs in a clean window. Never paste one worker's raw output into the next worker's prompt.

Named patterns

Pattern	Shape	Where COG uses it
Act-observe (ReAct)	reason → act → observe → repeat	base of every COG loop
Reflect-retry (Reflexion)	on failure, write the lesson, retry differently	url-dump / scout fetch retries, daily-brief re-search
Plan-execute-verify	plan steps, run them, verify each	knowledge-consolidation passes
Evaluator-optimizer	generate, score against criteria, repeat until it passes	daily-brief item verify, url-dump quality gate
Orchestrator-workers	split into subtasks, run in fresh windows, synthesize	team-mode scans, auto-research threads, team-brief
Loop-until-dry	keep going until K passes in a row surface nothing new	knowledge-consolidation theme extraction
Human-in-the-loop	escalate or ask when the loop is stuck or the call is the user's	weekly-checkin reflection, onboarding

Failure modes and fixes

Failure	Fix
Context overflow / drift	compact, prune, externalize to vault, isolate sub-agents
Silent infinite loop	no-progress detection plus a hard cap
Hallucinated success	trust the deterministic verifier, never self-report
Compounding errors	verify early and every pass, not only at the end
Cost blowup	budget guard, and stop at "good enough", not "perfect"
Goal drift	keep the goal and stop conditions written at the top of the loop's state

How skills use this

A skill's ## Loop Engineering section should be short and concrete. It names:

1. The loop in one or two lines (what repeats).
2. The verifier (the mechanical pass/fail).
3. The termination conditions (verifier plus safety exits).
4. The pattern(s) from the table above.

It does not restate this skill. It points here.