Autonomous Loop Patterns

Core Principle: Reviewer Never Authored

The agent that reviews work must never be the agent that authored it.

This is the single most important principle for autonomous quality. Self-review is unreliable -- the same blind spots that caused the error will miss it during review.

Implementation:

• Use a separate agent instance (different subagent_type or name) for review
• The reviewer receives only the output + acceptance criteria, not the generation prompt
• Reviewer can request changes but never edits directly -- sends feedback to the author

Pattern 1: Generate -> Validate -> Fix

The most common autonomous loop. Generate output, validate against criteria, fix if needed.

+----------+     +----------+     +----------+
| Generate |---->| Validate |---->|   Fix    |--+
|          |     |          |     |          |  |
+----------+     +----+-----+     +----------+  |
                      | Pass                     |
                      v                          |
                 +----------+                    |
                 |  Accept  |<-------------------+
                 +----------+     (max 3 iterations)

When to use: Code generation, document creation, configuration authoring

MAX_ITERATIONS = 3

for iteration in range(MAX_ITERATIONS):
    if iteration == 0:
        output = generate(prompt, context)
    else:
        output = fix(output, validation_errors, context)

    is_valid, errors = validate(output, acceptance_criteria)

    if is_valid:
        return accept(output)

return escalate_to_human(output, errors)

Guard rails:

• Hard cap on iterations (3 is typical, never exceed 5)
• Each iteration must reduce error count -- if errors increase, break
• Track token cost per iteration -- escalate if cost exceeds threshold

Pattern 2: Explore -> Hypothesize -> Test

For debugging and investigation. Gather evidence, form theory, validate.

+----------+     +-------------+     +----------+
| Explore  |---->| Hypothesize |---->|   Test   |--+
| (gather  |     | (form       |     | (verify  |  |
|  evidence)|    |  theory)    |     |  theory) |  |
+----------+     +-------------+     +----+-----+  |
                                          | Fail   |
                                          v        |
                                     +----------+  |
                                     | Refine   |--+
                                     | hypothesis|
                                     +----------+

When to use: Bug investigation, root cause analysis, codebase exploration

Guard rails:

• Track hypotheses tested to avoid circular reasoning
• Max 5 hypotheses before requesting human input
• Evidence must be concrete (file:line references, error messages)

Pattern 3: Plan -> Execute -> Verify -> Adjust

For multi-step implementation tasks.

+----------+     +----------+     +----------+     +----------+
|   Plan   |---->| Execute  |---->|  Verify  |---->|  Adjust  |--+
| (steps)  |     | (step N) |     | (tests)  |     | (plan)   |  |
+----------+     +----------+     +----------+     +----------+  |
     ^                                                            |
     +------------------------------------------------------------+

When to use: Feature implementation, refactoring, migration tasks

Guard rails:

• Plan must be approved before execution starts
• Verify after EACH step, not just at the end
• Adjustment can only modify future steps, never rewrite completed ones
• If >50% of plan needs adjustment, re-plan from scratch

Pattern 4: Diverge -> Converge -> Select

For creative or design tasks where multiple approaches are valid.

+------------+     +------------+     +----------+
|  Diverge   |---->|  Converge  |---->|  Select  |
| (generate  |     | (evaluate  |     | (pick    |
|  N options)|     |  trade-offs)|    |  best)   |
+------------+     +------------+     +----------+

When to use: Architecture decisions, API design, UI alternatives

Guard rails:

• Generate minimum 3 options (avoids false dichotomies)
• Evaluation criteria defined BEFORE divergence (prevents bias)
• Selection must reference criteria -- no "gut feeling"

Pattern 5: Seed -> Expand -> Prune

For building up content or code incrementally.

+----------+     +----------+     +----------+
|   Seed   |---->|  Expand  |---->|  Prune   |--+
| (minimal |     | (add     |     | (remove  |  |
|  version)|     |  features)|    |  bloat)  |  |
+----------+     +----------+     +----------+  |
                      ^                          |
                      +--------------------------+
                      (until scope complete)

When to use: MVP development, documentation, test suite building

Guard rails:

• Seed must be complete and working before expansion
• Each expansion adds ONE feature/section
• Prune after every 3 expansions
• Prune agent is separate from expand agent (reviewer-never-authored)

Pattern 6: Observe -> Orient -> Decide -> Act (OODA)

For reactive, event-driven agent workflows.

+----------+     +----------+     +----------+     +----------+
| Observe  |---->|  Orient  |---->|  Decide  |---->|   Act    |
| (monitor |     | (analyze |     | (choose  |     | (execute |
|  events) |     |  context)|     |  action) |     |  action) |
+----------+     +----------+     +----------+     +----------+
     ^                                                    |
     +----------------------------------------------------+

When to use: Monitoring, incident response, CI/CD automation

Guard rails:

• Observation must be fresh (re-check state before acting)
• Orientation must include context from previous loops
• Decision must be logged for audit trail
• Action must be reversible or confirmed

Applying Patterns

Choosing the Right Pattern

Task Type	Recommended Pattern
Code generation / editing	Generate -> Validate -> Fix
Bug investigation	Explore -> Hypothesize -> Test
Feature implementation	Plan -> Execute -> Verify -> Adjust
Architecture / design	Diverge -> Converge -> Select
Incremental building	Seed -> Expand -> Prune
Monitoring / ops	OODA

Combining Patterns

Patterns can be nested. For example:

• Plan -> Execute where each Execute step uses Generate -> Validate -> Fix
• Diverge -> Converge where each option is built with Seed -> Expand -> Prune
• OODA where the Act phase uses Plan -> Execute -> Verify -> Adjust

Universal Guard Rails

Apply these to ALL patterns:

1. Max iterations: Every loop has a hard cap (typically 3-5)
2. Cost tracking: Monitor token spend per iteration
3. Progress check: Each iteration must demonstrably advance toward the goal
4. Escalation path: Clear handoff to human when loop exhausts iterations
5. Audit trail: Log each iteration's input, output, and decision