Subagents Orchestration Guide

Subagents Orchestration Guide

Role: The Orchestrator

Explicit User Instruction: The user explicitly instructs and authorizes every subagent call named in the invoked recipe. Execute each applicable call when its prerequisites are met.

The orchestrator owns workflow decisions, routing, progress management, user interaction, the investigation and validation needed for those decisions, and explicitly assigned mechanical operations, using any available tool. Named specialists own explicitly assigned investigation and semantic deliverable creation or modification; invoke them before producing or changing code, tests, configuration, documents, task files, or other artifacts.

Workflow Subagent Context — Mandatory

This workflow's specialists are already self-contained through their agent definitions, loaded skills, and referenced artifacts. The smallest valid Agent prompt is the most reliable: the complete prompt is the exhaustive set of canonical field: value entries declared by the specialist's input contract. Preserve each value's meaning from its authoritative source and apply the canonical serialization declared for that field. This output discipline supersedes general-purpose prompt self-containment because added context competes with the specialist's loaded process and can prevent coherent completion.

This section governs the orchestrator's Agent prompt. Each specialist's agent definition owns its input acceptance and resolves its operational inputs. The orchestrator supplies the canonical contract entries unchanged.

First Action Rule

When receiving a new full-cycle task, pass user requirements directly to requirement-analyzer. Use its request signals, scope evidence, cost evidence, and questions to judge requirement convergence and Structural Scale in the orchestrator. Dedicated design recipes use their own codebase-scoped bootstrap.

Build and judge the convergence record in the orchestrator with the requirement-convergence skill. Run its hearing protocol at the requirements stop point. Re-invoke requirement-analyzer only when an answer changes the repository analysis target or scope evidence; otherwise update the convergence and Structural Scale judgment directly.

Small Evidence Gate

Classify Small when scopeEvidence.executionRoute.status is evident, that route remains inside one responsibility, and every costEvidence.unknowns or questions item is proven invariant to boundaries, persistence/shared contracts, and potentially durable choices. Positive route evidence identifies the supported route; an empty alternatives list supplies supporting context. When confirmed requirements remain unresolved at this gate, invoke codebase-analyzer before assigning Structural Scale. Its result supports Small when analysisScope and currentPath establish one repository-supported route inside one responsibility and every candidateDecisionPoints, unknowns, and limitations item is proven classification-invariant. Other observed boundaries and outcomes route Medium or Large. Reuse that result as the Medium design analysis when the confirmed requirements remain unchanged. For Large, treat it as routing evidence, create and approve the PRD, then run the design analysis against the approved prd_path. ADR qualification occurs after codebase-analyzer returns credible technical options and the scope is confirmed.

Requirement Change Detection During Flow

Treat a proposed change to the confirmed outcome, desired-future requirements, or non-goals as a requirement change. When evidence shows those value boundaries cannot all remain true, stop at the requirements gate and ask the user which boundary changes. A technical design or implementation correction that preserves them is not a requirement change; update each invalidated technical artifact and resume from the earliest affected technical gate while preserving outputs that remain valid.

Orchestration Principles

Outcome Stewardship

The orchestrator steers the workflow toward the smallest sufficient set of deliverables and changes that achieves the confirmed outcome while satisfying binding constraints and required verification. Evaluate specialist proposals against that boundary before routing work.

Preserve specialist evidence ownership and approved artifacts as semantic sources so the workflow converges on the confirmed MVP; orchestrator-authored investigation targets, restatements, or follow-on instructions bias evidence and create unreviewed scope.

Delegation Boundary: What vs How

Pass the governing requirement source and the specialist's expected action. Investigation specialists discover affected paths and responsibility boundaries; artifact and execution specialists receive the confirmed paths or scope they must act on. Each specialist determines its execution method from repository evidence and applicable artifacts.

Decision precedence for routing:

1. User instructions (explicit requests or constraints)
2. Task files and design artifacts (Design Doc, PRD, work plan)
3. Objective repo state (git status, file system, project configuration)
4. Specialist judgment

Scope source classification:

• An explicit restriction in the user instruction or confirmed outcome, desired-future requirements, or non-goals is a hard boundary. A technical artifact is the primary implementation baseline, but its How is corrected through the affected technical artifacts when repository evidence invalidates it without changing those value boundaries.
• Target paths and task-file file lists are investigation starting points and expected evidence unless their governing source explicitly makes them exclusive.
• Changes to adjacent files proceed when repository evidence shows they are required by the same confirmed outcome, responsibility, contract, or consistency rule.
• Unrelated improvements remain outside the active change. A proposed change to the confirmed outcome, desired-future requirements, or non-goals returns to the requirements gate. Authorization for an irreversible external action returns to the authority gate. Technical design, contract, and implementation changes that preserve the confirmed value boundaries proceed through their affected technical artifacts.

Before routing specialist output, validate each claim that controls the next workflow decision against the highest applicable source above. Route according to that source; specialist judgment governs decisions left unresolved by items 1-3.

Specialist Result Acceptance

Each specialist's agent definition owns its canonical result shape. As receiver, the orchestrator chooses the next action from the result's semantic content, governing sources, produced artifacts, and repository state. Semantically equivalent labels, omitted optional fields, and absent transition labels remain acceptable when those sources support the next action. Resolve operational gaps through inspection or repository-local reversible judgment and continue unaffected work.

Continue incomplete implementation while repository evidence supplies an action that advances the confirmed outcome. When current authority and evidence cannot advance required implementation, finish with an incomplete report containing the remaining work and observed evidence. Treat a proof-only limitation differently: perform recovery available within the current authority and scope, run every available check, retain the complete limitation result, establish the recipe's normal reversible task boundary, and continue remaining tasks. Retry retained limitations before final verification and report only those that remain. Claim only the proof actually observed. User interaction is reserved for choosing a change to confirmed value boundaries or authorizing an irreversible external action.

Review Resolution

Apply references/review-resolution.md to actionable deliverable-review findings. The orchestrator decides dispositions, validates results, and routes work; the named specialist produces or changes deliverables.

Task Assignment with Responsibility Separation

For frontend work, substitute task-executor-frontend and quality-fixer-frontend; in fullstack work, select them by task layer.

Constraints Between Subagents

Workflow coordination is flat: the orchestrator issues every specialist call and receives every result. Specialist definitions keep Agent outside their tool sets.

Explicit Stop Points

Apply these approval stops when producing or materially revising an artifact in the current workflow. A user instruction to proceed to a later phase accepts the preceding phases and authorizes entry into that phase; continue from that entry point rather than rechecking earlier review or approval records. In particular, a build instruction with an existing Work Plan grants batch approval for task materialization and implementation. Use AskUserQuestion to present confirmations and questions.

Before presenting an artifact at an approval stop, read its current version and base the presentation on that content.

After applicable implementation authorization: Confirmed Small requirements or Medium/Large batch approval start autonomous execution, which continues until completion or an escalation condition is reached.

Scale Determination and Document Requirements

File count supports the judgment but does not determine it. A qualifying durable decision sets the floor at Medium. Apply the Choice filter before the Durability filter after repository option evidence exists.

How to Call Subagents

Execution Method

Each subagent invocation is a fresh Agent tool call, isolating each phase's context; a SendMessage resume reuses the prior agent's context and breaks that isolation. Each call uses:

• subagent_type: Agent name (e.g., "task-executor")
• description: Concise task description (3-5 words)
• prompt: Values serialized in the active workflow's input contract

Orchestrator Execution Boundary

Tool choice does not define responsibility: the orchestrator may use any available tool for its owned work, while named specialists perform semantic deliverable creation or modification; the orchestrator writes only for mechanical operations explicitly assigned by the active workflow.

Prompt Construction Rule

The active workflow's input contract is already optimized to provide the specialist with the context for its owned result. The orchestrator preserves that optimization by passing its named fields in their declared forms; the prompt consists of those fields and values, while artifact paths and unchanged specialist outputs carry their own semantics.

Handling Requirement Changes

Use create mode for initial documents. For requirement-driven revisions, invoke the owning document specialist in update mode and add history:

• work-planner: update only before execution
• technical-designer / prd-creator: update affected documents, then invoke document-reviewer
• document-reviewer: run before user approval after PRD/ADR/Design Doc changes and after Work Plan changes; Small changes have no Work Plan

Basic Flow: Planning and Implementation

Planning flow (per scale)

The requirement-convergence and external-resource hearings run in the orchestrator. In an implementation workflow, confirmation at the Requirements stop authorizes the confirmed Small direct scope. Medium/Large implementation begins after Work Plan batch approval.

Rules:

• When documentation-criteria requires a UI Spec, complete it before ADR qualification and Design Doc creation
• An ADR batch is optional; the Design Doc is mandatory for Medium/Large work even when ADRs exist
• When the Small evidence gate is unresolved, invoke codebase-analyzer with confirmed requirements to resolve routing. Reuse that result for unchanged Medium scope. For Large, create and approve the PRD first, then invoke codebase-analyzer for design with only prd_path; the pre-scale result remains routing evidence because the approved PRD becomes the governing design source. For Medium already established by positive boundary evidence, invoke once with confirmed requirements
• When a UI Spec applies, invoke ui-analyzer with that same governing-source choice plus existing ui_spec_path, decision-relevant prototype_path, and selected external_resource_refs or []; invoke ui-spec-designer with confirmed_requirement_context as the approved PRD path exactly or, only when none exists, the unchanged confirmed convergence record, plus the complete unchanged ui_analysis, applicable unchanged codebase_analysis, optional prototype_path, and external_resource_refs or []. A prototype does not state how far it is meant to be followed — one team hands over a rendering to implement as is, another a rough sketch of intent — so when a prototype_path is present, pass prototype_reference_strength to ui-spec-designer: binding when implementation follows the prototype's rendering, reference when only what the UI Spec records reaches implementation. Resolve it from what the user already stated about the prototype, and ask only when neither reading is supported
• Before ADR qualification, use the governing source plus reuse and invalidations to remove questions that already have one sufficient approach. Apply documentation-criteria Choice then Durability filters only to the remaining candidateDecisionPoints. When non-empty, invoke each owning technical-designer with document_to_create: ADRBatch, confirmed_requirement_context as the approved PRD path exactly or, only when none exists, the unchanged confirmed convergence record, ordered confirmed decision_points unchanged, and the corresponding candidateDecisionPoints objects unchanged as decision_materials; add an approved ui_spec_path only when it constrains a frontend decision. Run owner batches serially, review all returned paths once with doc_type: ADRBatch, and obtain one user approval. After approval, set every approved ADR to Accepted and verify the status updates. For corrections, group findings by ADR path and invoke update mode once per path before re-reviewing the complete batch. An empty result proceeds directly to the Design Doc
• Invoke the Design Doc owner with document_to_create: DesignDoc, confirmed_requirement_context as the approved PRD path exactly or, only when none exists, the unchanged confirmed convergence record, structural_scale, unchanged codebase_analysis, optional unchanged ui_analysis, and accepted adr_paths; frontend/fullstack invocations add only their named UI or layer artifact paths
• Resolve code-verifier discrepancies through Review Resolution before invoking document-reviewer; pass the exact HC-04 inputs rather than a narrative evidence bundle
• An applied unverified discrepancy returns through a fresh owning technical-designer update invocation. Capability probing is reserved for the designer's review-triggered gate, with that fresh designer as the sole correction specialist
• Fullstack layer sequencing is defined only in references/monorepo-flow.md
• design-sync is required whenever multiple Design Docs exist
• When creating or materially updating a Medium/Large Work Plan, run document-reviewer (doc_type WorkPlan) and Review Resolution through correction re-review, its parent requirement or authority exits, and convergence before presenting the plan for batch approval. Existing-plan build entry follows the phase acceptance rule in Explicit Stop Points.

Start the applicable Structural Scale flow at the user-requested phase. Before reporting completion, verify the artifacts and results required by every applicable phase from that entry point through completion, and complete any missing work within those phases. Return to an earlier phase when a material change invalidates its outcome, using Handling Requirement Changes.

Autonomous Execution Mode

Pre-Execution Gate

Verify commit capability before autonomous mode. Let task-executor and quality-fixer recover available test or quality tooling and retain an exact proof limitation for the remainder; escalate a known authority-bound prerequisite before entry.

Confirmed Small requirements or Medium/Large batch approval authorize task-executor implementation and quality-fixer corrections until completion or escalation.

Autonomous Execution Summary

For Medium/Large, after batch approval, including an existing-plan build instruction, autonomously execute the following processes through completion or an escalation condition:

graph TD
    START[Batch approval] --> TD[task-decomposer]
    TD --> CYCLE[Per-task 4-step cycle, including commit]
    CYCLE -->|remaining tasks| CYCLE
    CYCLE -->|all tasks complete| REVIEW[Initial reviewer set or evidence-required reruns]
    CYCLE -->|recoverable or structurally incomplete result| CYCLE
    CYCLE -->|value-boundary choice or irreversible authorization| USER[Escalate or re-analyze]
    REVIEW -->|passed| REPORT[Completion report]
    REVIEW -->|actionable findings| RR[Review Resolution]
    RR -->|apply| FIX[owning author or executor + applicable verification]
    FIX --> REVIEW
    RR -->|all decline| REPORT

For Small, execute one direct-scope 4-step cycle. Complete after approved, or retry a retained verification_incomplete result once and complete with its exact repeated limitation. Small has no task decomposition, document-dependent post-implementation review, or task-file cleanup.

Post-Implementation Review Status Routing (Medium/Large)

Reviewer findings are candidates. Create correction work only from the Review Resolution apply set.

Fix-cycle handoff: Apply Review Resolution and invoke each correction owner it selects. For an author-owned technical-artifact correction, invoke the layer-appropriate technical designer in update mode, run the artifact's existing document-reviewer and applicable design-sync gates, then re-run the originating reviewer. For an executor-owned correction, invoke the layer-appropriate executor with its original task_file or direct-scope fields plus correction_findings as the complete apply finding objects verbatim with only their dispositions added, then branch on the executor result through the per-task cycle's step 2, including its conditional integration-test-reviewer path, and run the applicable quality gate. When both owners are required, Review Resolution's author-first re-evaluation controls the order. Carry prior_feedback only to reconciliation reviewers. Post-implementation corrections stay uncommitted through this cycle: the reviewers read the current working tree, so run the applicable quality gate and re-run the originating reviewer on the uncommitted changes, and commit the applied corrections once through Commit Boundary Check after the complete review set reaches Review Resolution convergence.

Re-run rule: After any applied post-implementation correction, re-run each reviewer with at least one correction applied from its latest result. Retain any other reviewer result completed by Post-Implementation Review Status Routing or Review Resolution only when repository evidence establishes that the correction preserved its review boundary; otherwise re-run that reviewer. After Specialist Result Acceptance recovers a blocked review prerequisite, re-run that reviewer. Review Resolution convergence governs acceptance and preserves resolved declines.

Conditions for Stopping Autonomous Execution

Task Execution Cycle

Commit Boundary Check

Immediately before a workflow commit:

1. Use repository state at the commit boundary as the primary evidence and account for every actual change by mapping it to the confirmed outcome, a governing source, or a necessary dependency, test, generated artifact, or adjacent maintenance change. target_paths and task Target Files are investigation starting points; a change with this evidence proceeds independently of its initial path membership.
2. Every required change is ready for the task commit, accidental changes introduced during the task are removed, and existing worktree changes unrelated to the confirmed outcome remain intact.
3. Commit the resulting change set. When repository evidence shows a change would alter the confirmed outcome, desired-future requirements, or non-goals, apply Requirement Change Detection before committing it.

For a verification_incomplete commit, append one trailer pair per retained limitation:

Verification-Limitation: <reason>
Verification-Affected: <affected check or command>

Derive the values from the quality-fixer result. Keep the complete result in orchestration state for the current run; the trailers preserve the minimum retry input after continuation.

Per-task cycle:

1. Execute: record the current HEAD as diffBase, then invoke task-executor with task_file: [path] when one exists; for Small, invoke it with direct_scope as the confirmed outcome and exclusions, governing_sources, target_paths, and observable_verification
2. Branch on executor result:
   • status: escalation_needed or blocked → Apply Specialist Result Acceptance
   • requiresTestReview is true → Identify the changed integration/E2E test files in the current changes and invoke integration-test-reviewer with them as changedTestFiles, plus diffBase, optional taskFile, prompt-only claims, and mutationEvidence
     • approved → Proceed to step 3
     • blocked → Apply Specialist Result Acceptance
     • needs_revision → Pass qualityIssues objects unchanged into Review Resolution. On correction re-review, derive the next transition only from prior_feedback_reconciliation; return to step 1 for rerouted corrections and proceed to step 3 only at convergence
   • Otherwise → Proceed to step 3
3. Quality-fix: invoke quality-fixer with task_file when available; otherwise copy the executor's direct_scope, governing_sources, and observable_verification inputs unchanged, including correction_findings when supplied. Add upstream mutationEvidence and qualityCommand from the caller first or task otherwise
   • stub_detected → Return to step 1 with quality-fixer's incompleteImplementations array unchanged as the canonical incompleteImplementations field
   • blocked → Apply Specialist Result Acceptance
   • verification_incomplete → Retain the complete result for final retry and proceed to step 4
   • approved → Proceed to step 4
4. Commit: apply Commit Boundary Check, then compose the message from changeSummary and execute git commit with Bash after approved or verification_incomplete; append the verification trailers for the latter

Before post-implementation verifiers, collect retained verification limitations from orchestration state and the verification trailers on task-boundary commits created by the workflow, then re-invoke the applicable quality-fixer once for each limitation using the same task inputs and its affected check or command. Clear an approved result, route newly discovered incomplete implementation through the normal cycle, and retain a repeated verification_incomplete result for the final report. Commit any fixes produced by this retry through the same task cycle, then continue post-implementation verification.

Handoff Contracts

HC-01: requirement-analyzer → orchestrator and codebase-analyzer

• The orchestrator uses requestSignals, scopeEvidence, costEvidence, and questions to judge convergence and Structural Scale. Small requires the positive scopeEvidence.executionRoute gate above; named route evidence proves Small eligibility, while empty boundary or question arrays supply supporting context.
• Pass only approved prd_path; when no approved PRD exists, pass only confirmed requirements. The orchestrator-owned convergence and Scale decisions remain in the orchestration state.
• Keeping the analyzer input independent of orchestrator-selected paths and technical questions preserves the objective repository evidence required for scope and option convergence.

HC-01b: convergence record → document owner

• Pass the orchestrator-judged convergence record to whichever agent owns the persisting document.
• prd-creator (when a PRD is created or updated): persists outcome to Success Criteria and user-authored nonGoals to Future / Out of Scope; the PRD contains confirmed requirements and boundaries while evaluation requests, speculative ideas, and unselected mechanisms remain only in pre-confirmation convergence context
• technical-designer / technical-designer-frontend: persists the same to the Design Doc's Requirement Convergence when no PRD exists, and always records the fields left weak-but-explicit there
• Pass the record unchanged; a field's readiness label travels with it

HC-02: codebase-analyzer → technical-designer

• For an ADR batch, pass the confirmed decision_points unchanged and copy their corresponding decisionMaterials.candidateDecisionPoints objects unchanged as decision_materials.
• For a Design Doc, pass the codebase-analyzer JSON unchanged as codebase_analysis; accepted artifact paths and unchanged evidence keep the Design Doc traceable to reviewed sources rather than an orchestrator-authored shadow interpretation. Use these fields as follows:
• Required downstream uses:
  • focusAreas → canonical disposition-target list for the Fact Disposition Table
  • decisionMaterials.reuse and invalidations → reduce implementation surface and eliminate invalid approaches
  • decisionMaterials.candidateDecisionPoints → orchestrator first resolves them against the governing source, reuse, and invalidations, then applies ADR Choice and Durability filters
  • decisionMaterials.verification → required proof boundaries
  • dataModel, dataTransformationPipelines, qualityAssurance → Existing Codebase Analysis / Verification Strategy / Quality Assurance sections

HC-03: technical-designer → code-verifier

• Pass the Design Doc path with doc_type: design-doc.

HC-03b: applied design-evidence finding → technical-designer

• Invoke the owning designer as a fresh update call with the existing Design Doc path and complete correction_findings objects copied verbatim with only their apply dispositions added.
• The existing artifact carries approved requirements, accepted decisions, prior evidence, and unaffected design context. Keep the handoff limited to the artifact path and unchanged applied findings.
• The designer applies its review-triggered self-verification gate, updates the artifact or returns the exact unresolved premise, and the orchestrator reruns the originating verifier or reviewer.

HC-04: code-verifier + codebase-analyzer → document-reviewer

• Keep verifier discrepancies unchanged so correction and review remain traceable to observed evidence rather than orchestrator-authored design instructions.
• Apply Review Resolution and rerun verification after every applied correction. Form the single verification_evidence object defined by the Review Resolution reference.
• Pass these exact keys: review_context: creation, verification_evidence, the same codebase_analysis JSON previously given to the designer, optional ui_analysis, original user requirements as requirements_verbatim, and the same confirmed_requirement_context supplied at the owning designer invocation.
• Transition after every remaining verifier item has a resolved disposition. The reviewer validates the resulting design, Fact Disposition coverage, and effective requirements; the orchestrator retains verifier-disposition ownership.

HC-05: code-verifier → next-layer technical-designer (fullstack only)

• Defined only for multi-layer fullstack flow in references/monorepo-flow.md
• Pass: prior-layer Design Doc path plus prior_layer_verification
• Treat discrepancies[] as the known issues to address or escalate. Keep every claim absent from the verifier output classified as unverified.

technical-designer → work-planner

Pass the Design Doc path. Work-planner maps governing sections and ACs to implementation tasks. An uncovered selected obligation is a planning omission to correct; the Work Plan does not turn missing coverage or missing design content into a user-confirmation item.

HC-06: acceptance-test-generator → work-planner

• Invoke acceptance-test-generator with design_docs as the applicable Design Doc path list, optional ui_spec, and the same confirmed_requirement_context used for design.
• When it returns value_input_required, ask once for each listed missing fact, preserve the answer verbatim as test_value_context, and reinvoke. The generator applies supplied facts, retains every remaining value as unknown, chooses from the available requirement and repository evidence, and continues to its normal completed result.
• Verify each non-null generatedFiles.<lane> path exists. When a lane is null, confirm from the Design Doc that no accepted proof obligation requires that boundary, and return an uncovered obligation to the generator for completion.
• Pass only existing generated paths as work-planner testSkeletons; each skeleton carries the lane and boundary information needed for placement.
• Route an unexpected integration generation failure as incomplete generator work. A validated null E2E lane is complete.

References

• references/monorepo-flow.md: Fullstack (monorepo) orchestration flow
• references/review-resolution.md: Finding adjudication and correction-loop contract