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name: design-synthesis type: simple depth: extended description: >- Synthesizes research findings into design decisions via codebase investigation. Use when (1) translating research into implementation approaches, (2) selecting between design alternatives, (3) executing after /research or deep-research, or (4) preparing input for /plan phase.

[H1][DESIGN-SYNTHESIS]

Dictum: Design decisions require grounded context before implementation.

Synthesize research findings into design decisions via light codebase investigation.

Workflow:

1. §INGEST — Load research artifact, parse original request
2. §SCAN — Light codebase investigation via parallel-dispatch (3-4 agents)
3. §EXPLORE — Generate 2-3 approaches with trade-offs
4. §SELECT — Commit to best approach with rationale
5. §OUTPUT — Structured design document

Dependencies:

• parallel-dispatch — Agent orchestration for codebase scan
• Research artifact — External findings from deep-research

Input:

• Research: Path to research artifact (research_{slug}.md)
• Request: Original user request/intent

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[1][INGEST]

Dictum: Grounded context prevents speculative design.

Load and parse inputs:

[INDEX]	Source	Extract
[1]	Research file	Findings, confidence levels, key sources
[2]	Request	Intent, scope boundaries, success criteria

Parse research structure:

• ## [1][FINDINGS] → Domain knowledge by category
• ## [2][CONFIDENCE] → High/Medium/Low ratings
• ## [3][SOURCES] → Attribution for decisions

[IMPORTANT]:

• [ALWAYS] Extract high-confidence findings as primary input.
• [ALWAYS] Note low-confidence areas as design risks.
• [NEVER] Proceed without understanding request intent.

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[2][SCAN]

Dictum: Pattern awareness prevents reinvention.

Dispatch 3-4 agents via parallel-dispatch for codebase context.

Agent Assignment:

[INDEX]	[AGENT]	[SCOPE]	[RETURNS]
[1]	Patterns	Similar implementations in codebase	Conventions, reusable patterns, prior art
[2]	Constraints	Project rules, architecture limits	Hard boundaries, style requirements
[3]	Interfaces	Entry/exit points for feature area	Touch points, consumers, integration surface

Agent Prompt Template:

Scope: [Specific investigation area]
Objective: Surface [patterns|constraints|interfaces] relevant to: [request summary]
Output: Bullet list of findings with file paths
Context: Research indicates: [key findings summary]
Exclusions: Do NOT analyze implementation details or specific file contents

[CRITICAL]:

• [ALWAYS] Dispatch ALL agents in ONE message block.
• [ALWAYS] Scope to patterns/constraints/interfaces—NOT implementation.
• [NEVER] Deep-dive into file contents—that's plan's job.

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[3][EXPLORE]

Dictum: Comparison reveals optimal trade-offs.

Generate 2-3 distinct approaches from research + scan findings.

Per Approach:

[INDEX]	Aspect	Content
[1]	Strategy	High-level implementation direction
[2]	Alignment	How it leverages research findings
[3]	Patterns	Which codebase conventions it follows
[4]	Trade-offs	Pros and cons

Approach Generation Criteria:

• Approach A: Most aligned with existing patterns (conservative)
• Approach B: Best leverage of research findings (optimal)
• Approach C: Simplest implementation path (minimal) — optional

[IMPORTANT]:

• [ALWAYS] Ground approaches in scan findings—no speculation.
• [ALWAYS] Include trade-off analysis per approach.
• [ALWAYS] Apply YAGNI—cut unnecessary scope from all approaches.
• [NEVER] Generate approaches without codebase evidence.

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[4][SELECT]

Dictum: Committed direction enables focused planning.

Select best approach via weighted criteria:

[INDEX]	Criterion	Weight	Evaluation
[1]	Pattern alignment	High	Matches existing codebase conventions
[2]	Research support	High	Backed by high-confidence findings
[3]	Simplicity	Medium	Minimal moving parts
[4]	Risk profile	Medium	Low-confidence areas minimized

Selection Output:

• Selected approach name
• Primary rationale (1-2 sentences)
• Key trade-off accepted

[CRITICAL]:

• [ALWAYS] Commit to ONE approach—no hedging.
• [ALWAYS] Document trade-off accepted.
• [NEVER] Defer selection to downstream phases.

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[5][OUTPUT]

Dictum: Downstream consumers require predictable structure.

Produce brainstorm.md with structure:

# [H1][DESIGN]: [Title]
>**Dictum:** *[Build target—refined from request]*

<br>

**Research Summary:** [Key findings relevant to design]

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## [1][APPROACHES]

### [1.1][APPROACH_A]: [Name]

| [INDEX] | [ASPECT]  | [DETAIL]                        |
| :-----: | --------- | ------------------------------- |
|   [1]   | Strategy  | [High-level direction]          |
|   [2]   | Alignment | [Research findings leveraged]   |
|   [3]   | Patterns  | [Codebase conventions followed] |
|   [4]   | Pros      | [Benefits]                      |
|   [5]   | Cons      | [Drawbacks]                     |

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### [1.2][APPROACH_B]: [Name]

| [INDEX] | [ASPECT]  | [DETAIL]                        |
| :-----: | --------- | ------------------------------- |
|   [1]   | Strategy  | [High-level direction]          |
|   [2]   | Alignment | [Research findings leveraged]   |
|   [3]   | Patterns  | [Codebase conventions followed] |
|   [4]   | Pros      | [Benefits]                      |
|   [5]   | Cons      | [Drawbacks]                     |

---
## [2][SELECTED_APPROACH]

| [INDEX] | [KEY]              | [VALUE]                |
| :-----: | ------------------ | ---------------------- |
|   [1]   | Choice             | [Approach name]        |
|   [2]   | Rationale          | [Why this approach]    |
|   [3]   | Trade-off Accepted | [What we're giving up] |

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## [3][DESIGN_CONSTRAINTS]

| [INDEX] | [CONSTRAINT]    | [SOURCE]        |
| :-----: | --------------- | --------------- |
|   [1]   | [Hard boundary] | [Codebase scan] |
|   [2]   | ...             | ...             |

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## [4][KEY_DECISIONS]

| [INDEX] | [DECISION]      | [CHOICE]          | [RATIONALE] |
| :-----: | --------------- | ----------------- | ----------- |
|   [1]   | [Design choice] | [Selected option] | [Why]       |
|   [2]   | [Design choice] | [Selected option] | [Why]       |

[CRITICAL]:

• [ALWAYS] Include all sections—downstream depends on structure.
• [ALWAYS] Table format for approaches and decisions.
• [NEVER] Prose paragraphs—tables and lists only.

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[6][VALIDATION]

Dictum: Incomplete synthesis cascades errors downstream.

[VERIFY]:

• Ingest: Research parsed, request intent extracted
• Scan: 3-4 agents dispatched in ONE message
• Explore: 2-3 approaches with trade-offs generated
• Select: ONE approach committed with rationale
• Output: All sections present, table format used
• YAGNI: Unnecessary scope cut from all approaches