diff --git a/README.md b/README.md
index 4e48754ad..4feb927bd 100644
--- a/README.md
+++ b/README.md
@@ -485,7 +485,8 @@ You're never locked in. The system adapts.
 
 | Command | What it does |
 |---------|--------------|
-| `/gsd:settings` | Toggle workflow agents (research, plan checker, verifier) |
+| `/gsd:settings` | Configure model profile and workflow agents |
+| `/gsd:set-profile <profile>` | Switch model profile (quality/balanced/budget) |
 | `/gsd:add-todo [desc]` | Capture idea for later |
 | `/gsd:check-todos` | List pending todos |
 | `/gsd:debug [desc]` | Systematic debugging with persistent state |
@@ -506,6 +507,23 @@ GSD stores project settings in `.planning/config.json`. Configure during `/gsd:n
 | `mode` | `yolo`, `interactive` | `interactive` | Auto-approve vs confirm at each step |
 | `depth` | `quick`, `standard`, `comprehensive` | `standard` | Planning thoroughness (phases × plans) |
 
+### Model Profiles
+
+Control which Claude model each agent uses. Balance quality vs token spend.
+
+| Profile | Planning | Execution | Verification |
+|---------|----------|-----------|--------------|
+| `quality` | Opus | Opus | Sonnet |
+| `balanced` (default) | Opus | Sonnet | Sonnet |
+| `budget` | Sonnet | Sonnet | Haiku |
+
+Switch profiles:
+```
+/gsd:set-profile budget
+```
+
+Or configure via `/gsd:settings`.
+
 ### Workflow Agents
 
 These spawn additional agents during planning/execution. They improve quality but add tokens and time.
diff --git a/commands/gsd/audit-milestone.md b/commands/gsd/audit-milestone.md
index 9bd0b004e..c2721828c 100644
--- a/commands/gsd/audit-milestone.md
+++ b/commands/gsd/audit-milestone.md
@@ -39,6 +39,24 @@ Glob: .planning/phases/*/*-VERIFICATION.md
 
 <process>
 
+## 0. Resolve Model Profile
+
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-integration-checker | sonnet | sonnet | haiku |
+
+Store resolved model for use in Task call below.
+
 ## 1. Determine Milestone Scope
 
 ```bash
@@ -83,7 +101,8 @@ Phase exports: {from SUMMARYs}
 API routes: {routes created}
 
 Verify cross-phase wiring and E2E user flows.",
-  subagent_type="gsd-integration-checker"
+  subagent_type="gsd-integration-checker",
+  model="{integration_checker_model}"
 )
 ```
 
diff --git a/commands/gsd/debug.md b/commands/gsd/debug.md
index d01e22a68..3c1ed8435 100644
--- a/commands/gsd/debug.md
+++ b/commands/gsd/debug.md
@@ -28,6 +28,24 @@ ls .planning/debug/*.md 2>/dev/null | grep -v resolved | head -5
 
 <process>
 
+## 0. Resolve Model Profile
+
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-debugger | opus | sonnet | sonnet |
+
+Store resolved model for use in Task calls below.
+
 ## 1. Check Active Sessions
 
 If active sessions exist AND no $ARGUMENTS:
@@ -82,6 +100,7 @@ Create: .planning/debug/{slug}.md
 Task(
   prompt=filled_prompt,
   subagent_type="gsd-debugger",
+  model="{debugger_model}",
   description="Debug {slug}"
 )
 ```
@@ -134,6 +153,7 @@ goal: find_and_fix
 Task(
   prompt=continuation_prompt,
   subagent_type="gsd-debugger",
+  model="{debugger_model}",
   description="Continue debug {slug}"
 )
 ```
diff --git a/commands/gsd/execute-phase.md b/commands/gsd/execute-phase.md
index 86dcfed31..21350d26b 100644
--- a/commands/gsd/execute-phase.md
+++ b/commands/gsd/execute-phase.md
@@ -38,6 +38,24 @@ Phase: $ARGUMENTS
 </context>
 
 <process>
+0. **Resolve Model Profile**
+
+   Read model profile for agent spawning:
+   ```bash
+   MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+   ```
+
+   Default to "balanced" if not set.
+
+   **Model lookup table:**
+
+   | Agent | quality | balanced | budget |
+   |-------|---------|----------|--------|
+   | gsd-executor | opus | sonnet | sonnet |
+   | gsd-verifier | sonnet | sonnet | haiku |
+
+   Store resolved models for use in Task calls below.
+
 1. **Validate phase exists**
    - Find phase directory matching argument
    - Count PLAN.md files
@@ -248,9 +266,9 @@ STATE_CONTENT=$(cat .planning/STATE.md)
 Spawn all plans in a wave with a single message containing multiple Task calls, with inlined content:
 
 ```
-Task(prompt="Execute plan at {plan_01_path}\n\nPlan:\n{plan_01_content}\n\nProject state:\n{state_content}", subagent_type="gsd-executor")
-Task(prompt="Execute plan at {plan_02_path}\n\nPlan:\n{plan_02_content}\n\nProject state:\n{state_content}", subagent_type="gsd-executor")
-Task(prompt="Execute plan at {plan_03_path}\n\nPlan:\n{plan_03_content}\n\nProject state:\n{state_content}", subagent_type="gsd-executor")
+Task(prompt="Execute plan at {plan_01_path}\n\nPlan:\n{plan_01_content}\n\nProject state:\n{state_content}", subagent_type="gsd-executor", model="{executor_model}")
+Task(prompt="Execute plan at {plan_02_path}\n\nPlan:\n{plan_02_content}\n\nProject state:\n{state_content}", subagent_type="gsd-executor", model="{executor_model}")
+Task(prompt="Execute plan at {plan_03_path}\n\nPlan:\n{plan_03_content}\n\nProject state:\n{state_content}", subagent_type="gsd-executor", model="{executor_model}")
 ```
 
 All three run in parallel. Task tool blocks until all complete.
diff --git a/commands/gsd/new-milestone.md b/commands/gsd/new-milestone.md
index 46ae4825b..44d8f66b1 100644
--- a/commands/gsd/new-milestone.md
+++ b/commands/gsd/new-milestone.md
@@ -122,6 +122,26 @@ git add .planning/PROJECT.md .planning/STATE.md
 git commit -m "docs: start milestone v[X.Y] [Name]"
 ```
 
+## Phase 6.5: Resolve Model Profile
+
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-project-researcher | opus | sonnet | haiku |
+| gsd-research-synthesizer | sonnet | sonnet | haiku |
+| gsd-roadmapper | opus | sonnet | sonnet |
+
+Store resolved models for use in Task calls below.
+
 ## Phase 7: Research Decision
 
 Use AskUserQuestion:
@@ -198,7 +218,7 @@ Your STACK.md feeds into roadmap creation. Be prescriptive:
 Write to: .planning/research/STACK.md
 Use template: ~/.claude/get-shit-done/templates/research-project/STACK.md
 </output>
-", subagent_type="gsd-project-researcher", description="Stack research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Stack research")
 
 Task(prompt="
 <research_type>
@@ -239,7 +259,7 @@ Your FEATURES.md feeds into requirements definition. Categorize clearly:
 Write to: .planning/research/FEATURES.md
 Use template: ~/.claude/get-shit-done/templates/research-project/FEATURES.md
 </output>
-", subagent_type="gsd-project-researcher", description="Features research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Features research")
 
 Task(prompt="
 <research_type>
@@ -281,7 +301,7 @@ Your ARCHITECTURE.md informs phase structure in roadmap. Include:
 Write to: .planning/research/ARCHITECTURE.md
 Use template: ~/.claude/get-shit-done/templates/research-project/ARCHITECTURE.md
 </output>
-", subagent_type="gsd-project-researcher", description="Architecture research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Architecture research")
 
 Task(prompt="
 <research_type>
@@ -319,7 +339,7 @@ Your PITFALLS.md prevents mistakes in roadmap/planning. For each pitfall:
 Write to: .planning/research/PITFALLS.md
 Use template: ~/.claude/get-shit-done/templates/research-project/PITFALLS.md
 </output>
-", subagent_type="gsd-project-researcher", description="Pitfalls research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Pitfalls research")
 ```
 
 After all 4 agents complete, spawn synthesizer to create SUMMARY.md:
@@ -343,7 +363,7 @@ Write to: .planning/research/SUMMARY.md
 Use template: ~/.claude/get-shit-done/templates/research-project/SUMMARY.md
 Commit after writing.
 </output>
-", subagent_type="gsd-research-synthesizer", description="Synthesize research")
+", subagent_type="gsd-research-synthesizer", model="{synthesizer_model}", description="Synthesize research")
 ```
 
 Display research complete banner and key findings:
@@ -548,7 +568,7 @@ Create roadmap for milestone v[X.Y]:
 
 Write files first, then return. This ensures artifacts persist even if context is lost.
 </instructions>
-", subagent_type="gsd-roadmapper", description="Create roadmap")
+", subagent_type="gsd-roadmapper", model="{roadmapper_model}", description="Create roadmap")
 ```
 
 **Handle roadmapper return:**
@@ -615,7 +635,7 @@ Use AskUserQuestion:
   Update the roadmap based on feedback. Edit files in place.
   Return ROADMAP REVISED with changes made.
   </revision>
-  ", subagent_type="gsd-roadmapper", description="Revise roadmap")
+  ", subagent_type="gsd-roadmapper", model="{roadmapper_model}", description="Revise roadmap")
   ```
 - Present revised roadmap
 - Loop until user approves
diff --git a/commands/gsd/new-project.md b/commands/gsd/new-project.md
index 88ec27d9f..65617390f 100644
--- a/commands/gsd/new-project.md
+++ b/commands/gsd/new-project.md
@@ -373,6 +373,26 @@ EOF
 
 **Note:** Run `/gsd:settings` anytime to update these preferences.
 
+## Phase 5.5: Resolve Model Profile
+
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-project-researcher | opus | sonnet | haiku |
+| gsd-research-synthesizer | sonnet | sonnet | haiku |
+| gsd-roadmapper | opus | sonnet | sonnet |
+
+Store resolved models for use in Task calls below.
+
 ## Phase 6: Research Decision
 
 Use AskUserQuestion:
@@ -453,7 +473,7 @@ Your STACK.md feeds into roadmap creation. Be prescriptive:
 Write to: .planning/research/STACK.md
 Use template: ~/.claude/get-shit-done/templates/research-project/STACK.md
 </output>
-", subagent_type="gsd-project-researcher", description="Stack research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Stack research")
 
 Task(prompt="
 <research_type>
@@ -492,7 +512,7 @@ Your FEATURES.md feeds into requirements definition. Categorize clearly:
 Write to: .planning/research/FEATURES.md
 Use template: ~/.claude/get-shit-done/templates/research-project/FEATURES.md
 </output>
-", subagent_type="gsd-project-researcher", description="Features research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Features research")
 
 Task(prompt="
 <research_type>
@@ -531,7 +551,7 @@ Your ARCHITECTURE.md informs phase structure in roadmap. Include:
 Write to: .planning/research/ARCHITECTURE.md
 Use template: ~/.claude/get-shit-done/templates/research-project/ARCHITECTURE.md
 </output>
-", subagent_type="gsd-project-researcher", description="Architecture research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Architecture research")
 
 Task(prompt="
 <research_type>
@@ -570,7 +590,7 @@ Your PITFALLS.md prevents mistakes in roadmap/planning. For each pitfall:
 Write to: .planning/research/PITFALLS.md
 Use template: ~/.claude/get-shit-done/templates/research-project/PITFALLS.md
 </output>
-", subagent_type="gsd-project-researcher", description="Pitfalls research")
+", subagent_type="gsd-project-researcher", model="{researcher_model}", description="Pitfalls research")
 ```
 
 After all 4 agents complete, spawn synthesizer to create SUMMARY.md:
@@ -594,7 +614,7 @@ Write to: .planning/research/SUMMARY.md
 Use template: ~/.claude/get-shit-done/templates/research-project/SUMMARY.md
 Commit after writing.
 </output>
-", subagent_type="gsd-research-synthesizer", description="Synthesize research")
+", subagent_type="gsd-research-synthesizer", model="{synthesizer_model}", description="Synthesize research")
 ```
 
 Display research complete banner and key findings:
@@ -799,7 +819,7 @@ Create roadmap:
 
 Write files first, then return. This ensures artifacts persist even if context is lost.
 </instructions>
-", subagent_type="gsd-roadmapper", description="Create roadmap")
+", subagent_type="gsd-roadmapper", model="{roadmapper_model}", description="Create roadmap")
 ```
 
 **Handle roadmapper return:**
@@ -875,7 +895,7 @@ Use AskUserQuestion:
   Update the roadmap based on feedback. Edit files in place.
   Return ROADMAP REVISED with changes made.
   </revision>
-  ", subagent_type="gsd-roadmapper", description="Revise roadmap")
+  ", subagent_type="gsd-roadmapper", model="{roadmapper_model}", description="Revise roadmap")
   ```
 - Present revised roadmap
 - Loop until user approves
diff --git a/commands/gsd/plan-phase.md b/commands/gsd/plan-phase.md
index b198a0402..fcb4de902 100644
--- a/commands/gsd/plan-phase.md
+++ b/commands/gsd/plan-phase.md
@@ -42,7 +42,7 @@ Normalize phase input in step 2 before any directory lookups.
 
 <process>
 
-## 1. Validate Environment
+## 1. Validate Environment and Resolve Model Profile
 
 ```bash
 ls .planning/ 2>/dev/null
@@ -50,6 +50,24 @@ ls .planning/ 2>/dev/null
 
 **If not found:** Error - user should run `/gsd:new-project` first.
 
+**Resolve model profile for agent spawning:**
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-phase-researcher | opus | sonnet | haiku |
+| gsd-planner | opus | opus | sonnet |
+| gsd-plan-checker | sonnet | sonnet | haiku |
+
+Store resolved models for use in Task calls below.
+
 ## 2. Parse and Normalize Arguments
 
 Extract from $ARGUMENTS:
@@ -190,6 +208,7 @@ Write research findings to: {phase_dir}/{phase}-RESEARCH.md
 Task(
   prompt=research_prompt,
   subagent_type="gsd-phase-researcher",
+  model="{researcher_model}",
   description="Research Phase {phase}"
 )
 ```
@@ -298,6 +317,7 @@ Before returning PLANNING COMPLETE:
 Task(
   prompt=filled_prompt,
   subagent_type="gsd-planner",
+  model="{planner_model}",
   description="Plan Phase {phase}"
 )
 ```
@@ -369,6 +389,7 @@ Return one of:
 Task(
   prompt=checker_prompt,
   subagent_type="gsd-plan-checker",
+  model="{checker_model}",
   description="Verify Phase {phase} plans"
 )
 ```
@@ -426,6 +447,7 @@ Return what changed.
 Task(
   prompt=revision_prompt,
   subagent_type="gsd-planner",
+  model="{planner_model}",
   description="Revise Phase {phase} plans"
 )
 ```
diff --git a/commands/gsd/progress.md b/commands/gsd/progress.md
index f12ba075f..9c59ca1aa 100644
--- a/commands/gsd/progress.md
+++ b/commands/gsd/progress.md
@@ -52,6 +52,7 @@ If missing both ROADMAP.md and PROJECT.md: suggest `/gsd:new-project`.
 - Read `.planning/STATE.md` for living memory (position, decisions, issues)
 - Read `.planning/ROADMAP.md` for phase structure and objectives
 - Read `.planning/PROJECT.md` for current state (What This Is, Core Value, Requirements)
+- Read `.planning/config.json` for settings (model_profile, workflow toggles)
   </step>
 
 <step name="recent">
@@ -80,6 +81,7 @@ If missing both ROADMAP.md and PROJECT.md: suggest `/gsd:new-project`.
 # [Project Name]
 
 **Progress:** [████████░░] 8/10 plans complete
+**Profile:** [quality/balanced/budget]
 
 ## Recent Work
 - [Phase X, Plan Y]: [what was accomplished - 1 line]
diff --git a/commands/gsd/quick.md b/commands/gsd/quick.md
index 8cd0a559c..c5f69d2d8 100644
--- a/commands/gsd/quick.md
+++ b/commands/gsd/quick.md
@@ -34,6 +34,27 @@ Orchestration is inline - no separate workflow file. Quick mode is deliberately
 </context>
 
 <process>
+**Step 0: Resolve Model Profile**
+
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-planner | opus | opus | sonnet |
+| gsd-executor | opus | sonnet | sonnet |
+
+Store resolved models for use in Task calls below.
+
+---
+
 **Step 1: Pre-flight validation**
 
 Check that an active GSD project exists:
@@ -145,6 +166,7 @@ Return: ## PLANNING COMPLETE with plan path
 </output>
 ",
   subagent_type="gsd-planner",
+  model="{planner_model}",
   description="Quick plan: ${DESCRIPTION}"
 )
 ```
@@ -178,6 +200,7 @@ Project state: @.planning/STATE.md
 </constraints>
 ",
   subagent_type="gsd-executor",
+  model="{executor_model}",
   description="Execute: ${DESCRIPTION}"
 )
 ```
diff --git a/commands/gsd/research-phase.md b/commands/gsd/research-phase.md
index b39851533..0fd2875aa 100644
--- a/commands/gsd/research-phase.md
+++ b/commands/gsd/research-phase.md
@@ -31,6 +31,24 @@ Normalize phase input in step 1 before any directory lookups.
 
 <process>
 
+## 0. Resolve Model Profile
+
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-phase-researcher | opus | sonnet | haiku |
+
+Store resolved model for use in Task calls below.
+
 ## 1. Normalize and Validate Phase
 
 ```bash
@@ -132,6 +150,7 @@ Write to: .planning/phases/${PHASE}-{slug}/${PHASE}-RESEARCH.md
 Task(
   prompt=filled_prompt,
   subagent_type="gsd-phase-researcher",
+  model="{researcher_model}",
   description="Research Phase {phase}"
 )
 ```
@@ -165,6 +184,7 @@ Research file: @.planning/phases/${PHASE}-{slug}/${PHASE}-RESEARCH.md
 Task(
   prompt=continuation_prompt,
   subagent_type="gsd-phase-researcher",
+  model="{researcher_model}",
   description="Continue research Phase {phase}"
 )
 ```
diff --git a/commands/gsd/set-profile.md b/commands/gsd/set-profile.md
new file mode 100644
index 000000000..9791d68f1
--- /dev/null
+++ b/commands/gsd/set-profile.md
@@ -0,0 +1,106 @@
+---
+name: set-profile
+description: Switch model profile for GSD agents (quality/balanced/budget)
+arguments:
+  - name: profile
+    description: "Profile name: quality, balanced, or budget"
+    required: true
+---
+
+<objective>
+Switch the model profile used by GSD agents. This controls which Claude model each agent uses, balancing quality vs token spend.
+</objective>
+
+<profiles>
+| Profile | Description |
+|---------|-------------|
+| **quality** | Opus everywhere except read-only verification |
+| **balanced** | Opus for planning, Sonnet for execution/verification (default) |
+| **budget** | Sonnet for writing, Haiku for research/verification |
+</profiles>
+
+<process>
+
+## 1. Validate argument
+
+```
+if $ARGUMENTS.profile not in ["quality", "balanced", "budget"]:
+  Error: Invalid profile "$ARGUMENTS.profile"
+  Valid profiles: quality, balanced, budget
+  STOP
+```
+
+## 2. Check for project
+
+```bash
+ls .planning/config.json 2>/dev/null
+```
+
+If no `.planning/` directory:
+```
+Error: No GSD project found.
+Run /gsd:new-project first to initialize a project.
+```
+
+## 3. Update config.json
+
+Read current config:
+```bash
+cat .planning/config.json
+```
+
+Update `model_profile` field (or add if missing):
+```json
+{
+  "model_profile": "$ARGUMENTS.profile"
+}
+```
+
+Write updated config back to `.planning/config.json`.
+
+## 4. Confirm
+
+```
+✓ Model profile set to: $ARGUMENTS.profile
+
+Agents will now use:
+[Show table from model-profiles.md for selected profile]
+
+Next spawned agents will use the new profile.
+```
+
+</process>
+
+<examples>
+
+**Switch to budget mode:**
+```
+/gsd:set-profile budget
+
+✓ Model profile set to: budget
+
+Agents will now use:
+| Agent | Model |
+|-------|-------|
+| gsd-planner | sonnet |
+| gsd-executor | sonnet |
+| gsd-verifier | haiku |
+| ... | ... |
+```
+
+**Switch to quality mode:**
+```
+/gsd:set-profile quality
+
+✓ Model profile set to: quality
+
+Agents will now use:
+| Agent | Model |
+|-------|-------|
+| gsd-planner | opus |
+| gsd-executor | opus |
+| gsd-verifier | sonnet |
+| ... | ... |
+```
+
+</examples>
diff --git a/commands/gsd/settings.md b/commands/gsd/settings.md
index 250c284c8..b4b14aa1c 100644
--- a/commands/gsd/settings.md
+++ b/commands/gsd/settings.md
@@ -1,6 +1,6 @@
 ---
 name: gsd:settings
-description: Configure GSD workflow toggles (research, plan checker, verifier)
+description: Configure GSD workflow toggles and model profile
 allowed-tools:
   - Read
   - Write
@@ -8,9 +8,9 @@ allowed-tools:
 ---
 
 <objective>
-Allow users to toggle workflow agents on/off via interactive settings.
+Allow users to toggle workflow agents on/off and select model profile via interactive settings.
 
-Updates `.planning/config.json` with workflow preferences that control whether research, plan checking, and verification agents are spawned.
+Updates `.planning/config.json` with workflow preferences and model profile selection.
 </objective>
 
 <process>
@@ -33,6 +33,7 @@ Parse current values (default to `true` if not present):
 - `workflow.research` — spawn researcher during plan-phase
 - `workflow.plan_check` — spawn plan checker during plan-phase
 - `workflow.verifier` — spawn verifier during execute-phase
+- `model_profile` — which model each agent uses (default: `balanced`)
 
 ## 3. Present Settings
 
@@ -40,6 +41,16 @@ Use AskUserQuestion with current values shown:
 
 ```
 AskUserQuestion([
+  {
+    question: "Which model profile for agents?",
+    header: "Model",
+    multiSelect: false,
+    options: [
+      { label: "Quality", description: "Opus everywhere except verification (highest cost)" },
+      { label: "Balanced (Recommended)", description: "Opus for planning, Sonnet for execution/verification" },
+      { label: "Budget", description: "Sonnet for writing, Haiku for research/verification (lowest cost)" }
+    ]
+  },
   {
     question: "Spawn Plan Researcher? (researches domain before planning)",
     header: "Research",
@@ -74,11 +85,12 @@ AskUserQuestion([
 
 ## 4. Update Config
 
-Merge new workflow settings into existing config.json:
+Merge new settings into existing config.json:
 
 ```json
 {
   ...existing_config,
+  "model_profile": "quality" | "balanced" | "budget",
   "workflow": {
     "research": true/false,
     "plan_check": true/false,
@@ -100,23 +112,25 @@ Display:
 
 | Setting              | Value |
 |----------------------|-------|
+| Model Profile        | {quality/balanced/budget} |
 | Plan Researcher      | {On/Off} |
 | Plan Checker         | {On/Off} |
 | Execution Verifier   | {On/Off} |
 
 These settings apply to future /gsd:plan-phase and /gsd:execute-phase runs.
 
-Override per-invocation with flags:
-- /gsd:plan-phase --research (force research)
-- /gsd:plan-phase --skip-research (skip research)
-- /gsd:plan-phase --skip-verify (skip plan check)
+Quick commands:
+- /gsd:set-profile <profile> — switch model profile
+- /gsd:plan-phase --research — force research
+- /gsd:plan-phase --skip-research — skip research
+- /gsd:plan-phase --skip-verify — skip plan check
 ```
 
 </process>
 
 <success_criteria>
 - [ ] Current config read
-- [ ] User presented with 3 toggle questions
-- [ ] Config updated with workflow section
+- [ ] User presented with 4 settings (profile + 3 toggles)
+- [ ] Config updated with model_profile and workflow section
 - [ ] Changes confirmed to user
 </success_criteria>
diff --git a/get-shit-done/references/model-profiles.md b/get-shit-done/references/model-profiles.md
new file mode 100644
index 000000000..870db8dd2
--- /dev/null
+++ b/get-shit-done/references/model-profiles.md
@@ -0,0 +1,73 @@
+# Model Profiles
+
+Model profiles control which Claude model each GSD agent uses. This allows balancing quality vs token spend.
+
+## Profile Definitions
+
+| Agent | `quality` | `balanced` | `budget` |
+|-------|-----------|------------|----------|
+| gsd-planner | opus | opus | sonnet |
+| gsd-roadmapper | opus | sonnet | sonnet |
+| gsd-executor | opus | sonnet | sonnet |
+| gsd-phase-researcher | opus | sonnet | haiku |
+| gsd-project-researcher | opus | sonnet | haiku |
+| gsd-research-synthesizer | sonnet | sonnet | haiku |
+| gsd-debugger | opus | sonnet | sonnet |
+| gsd-codebase-mapper | sonnet | haiku | haiku |
+| gsd-verifier | sonnet | sonnet | haiku |
+| gsd-plan-checker | sonnet | sonnet | haiku |
+| gsd-integration-checker | sonnet | sonnet | haiku |
+
+## Profile Philosophy
+
+**quality** - Maximum reasoning power
+- Opus for all decision-making agents
+- Sonnet for read-only verification
+- Use when: quota available, critical architecture work
+
+**balanced** (default) - Smart allocation
+- Opus only for planning (where architecture decisions happen)
+- Sonnet for execution and research (follows explicit instructions)
+- Sonnet for verification (needs reasoning, not just pattern matching)
+- Use when: normal development, good balance of quality and cost
+
+**budget** - Minimal Opus usage
+- Sonnet for anything that writes code
+- Haiku for research and verification
+- Use when: conserving quota, high-volume work, less critical phases
+
+## Resolution Logic
+
+Orchestrators resolve model before spawning:
+
+```
+1. Read .planning/config.json
+2. Get model_profile (default: "balanced")
+3. Look up agent in table above
+4. Pass model parameter to Task call
+```
+
+## Switching Profiles
+
+Runtime: `/gsd:set-profile <profile>`
+
+Per-project default: Set in `.planning/config.json`:
+```json
+{
+  "model_profile": "balanced"
+}
+```
+
+## Design Rationale
+
+**Why Opus for gsd-planner?**
+Planning involves architecture decisions, goal decomposition, and task design. This is where model quality has the highest impact.
+
+**Why Sonnet for gsd-executor?**
+Executors follow explicit PLAN.md instructions. The plan already contains the reasoning; execution is implementation.
+
+**Why Sonnet (not Haiku) for verifiers in balanced?**
+Verification requires goal-backward reasoning - checking if code *delivers* what the phase promised, not just pattern matching. Sonnet handles this well; Haiku may miss subtle gaps.
+
+**Why Haiku for gsd-codebase-mapper?**
+Read-only exploration and pattern extraction. No reasoning required, just structured output from file contents.
diff --git a/get-shit-done/workflows/execute-phase.md b/get-shit-done/workflows/execute-phase.md
index f2ff7ac57..93f3a327b 100644
--- a/get-shit-done/workflows/execute-phase.md
+++ b/get-shit-done/workflows/execute-phase.md
@@ -13,7 +13,27 @@ Read config.json for planning behavior settings.
 
 <process>
 
-<step name="load_project_state" priority="first">
+<step name="resolve_model_profile" priority="first">
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-executor | opus | sonnet | sonnet |
+| gsd-verifier | sonnet | sonnet | haiku |
+| general-purpose | — | — | — |
+
+Store resolved models for use in Task calls below.
+</step>
+
+<step name="load_project_state">
 Before any operation, read project state:
 
 ```bash
@@ -274,7 +294,7 @@ Plans with `autonomous: false` require user interaction.
 
 1. **Spawn agent for checkpoint plan:**
    ```
-   Task(prompt="{subagent-task-prompt}", subagent_type="general-purpose")
+   Task(prompt="{subagent-task-prompt}", subagent_type="gsd-executor", model="{executor_model}")
    ```
 
 2. **Agent runs until checkpoint:**
@@ -313,7 +333,8 @@ Plans with `autonomous: false` require user interaction.
    ```
    Task(
      prompt=filled_continuation_template,
-     subagent_type="general-purpose"
+     subagent_type="gsd-executor",
+     model="{executor_model}"
    )
    ```
 
@@ -389,7 +410,8 @@ Phase goal: {goal from ROADMAP.md}
 
 Check must_haves against actual codebase. Create VERIFICATION.md.
 Verify what actually exists in the code.",
-  subagent_type="gsd-verifier"
+  subagent_type="gsd-verifier",
+  model="{verifier_model}"
 )
 ```
 
diff --git a/get-shit-done/workflows/execute-plan.md b/get-shit-done/workflows/execute-plan.md
index de551857f..d21c978f1 100644
--- a/get-shit-done/workflows/execute-plan.md
+++ b/get-shit-done/workflows/execute-plan.md
@@ -11,7 +11,25 @@ Read config.json for planning behavior settings.
 
 <process>
 
-<step name="load_project_state" priority="first">
+<step name="resolve_model_profile" priority="first">
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-executor | opus | sonnet | sonnet |
+
+Store resolved model for use in Task calls below.
+</step>
+
+<step name="load_project_state">
 Before any operation, read project state:
 
 ```bash
@@ -219,7 +237,7 @@ No segmentation benefit - execute entirely in main
 ```
 1. Run init_agent_tracking step first (see step below)
 
-2. Use Task tool with subagent_type="gsd-executor":
+2. Use Task tool with subagent_type="gsd-executor" and model="{executor_model}":
 
    Prompt: "Execute plan at .planning/phases/{phase}-{plan}-PLAN.md
 
@@ -371,7 +389,7 @@ For Pattern A (fully autonomous) and Pattern C (decision-dependent), skip this s
 
    B. If routing = Subagent:
       ```
-      Spawn Task tool with subagent_type="gsd-executor":
+      Spawn Task tool with subagent_type="gsd-executor" and model="{executor_model}":
 
       Prompt: "Execute tasks [task numbers/names] from plan at [plan path].
 
diff --git a/get-shit-done/workflows/map-codebase.md b/get-shit-done/workflows/map-codebase.md
index 48fdf7e20..df59b5993 100644
--- a/get-shit-done/workflows/map-codebase.md
+++ b/get-shit-done/workflows/map-codebase.md
@@ -22,7 +22,25 @@ Documents are reference material for Claude when planning/executing. Always incl
 
 <process>
 
-<step name="check_existing" priority="first">
+<step name="resolve_model_profile" priority="first">
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-codebase-mapper | sonnet | haiku | haiku |
+
+Store resolved model for use in Task calls below.
+</step>
+
+<step name="check_existing">
 Check if .planning/codebase/ already exists:
 
 ```bash
@@ -73,7 +91,7 @@ Continue to spawn_agents.
 <step name="spawn_agents">
 Spawn 4 parallel gsd-codebase-mapper agents.
 
-Use Task tool with `subagent_type="gsd-codebase-mapper"` and `run_in_background=true` for parallel execution.
+Use Task tool with `subagent_type="gsd-codebase-mapper"`, `model="{mapper_model}"`, and `run_in_background=true` for parallel execution.
 
 **CRITICAL:** Use the dedicated `gsd-codebase-mapper` agent, NOT `Explore`. The mapper agent writes documents directly.
 
@@ -82,6 +100,7 @@ Use Task tool with `subagent_type="gsd-codebase-mapper"` and `run_in_background=
 Task tool parameters:
 ```
 subagent_type: "gsd-codebase-mapper"
+model: "{mapper_model}"
 run_in_background: true
 description: "Map codebase tech stack"
 ```
@@ -104,6 +123,7 @@ Explore thoroughly. Write documents directly using templates. Return confirmatio
 Task tool parameters:
 ```
 subagent_type: "gsd-codebase-mapper"
+model: "{mapper_model}"
 run_in_background: true
 description: "Map codebase architecture"
 ```
@@ -126,6 +146,7 @@ Explore thoroughly. Write documents directly using templates. Return confirmatio
 Task tool parameters:
 ```
 subagent_type: "gsd-codebase-mapper"
+model: "{mapper_model}"
 run_in_background: true
 description: "Map codebase conventions"
 ```
@@ -148,6 +169,7 @@ Explore thoroughly. Write documents directly using templates. Return confirmatio
 Task tool parameters:
 ```
 subagent_type: "gsd-codebase-mapper"
+model: "{mapper_model}"
 run_in_background: true
 description: "Map codebase concerns"
 ```
diff --git a/get-shit-done/workflows/verify-work.md b/get-shit-done/workflows/verify-work.md
index c1534f42d..d6867247c 100644
--- a/get-shit-done/workflows/verify-work.md
+++ b/get-shit-done/workflows/verify-work.md
@@ -20,6 +20,25 @@ No Pass/Fail buttons. No severity questions. Just: "Here's what should happen. D
 
 <process>
 
+<step name="resolve_model_profile" priority="first">
+Read model profile for agent spawning:
+
+```bash
+MODEL_PROFILE=$(cat .planning/config.json 2>/dev/null | grep -o '"model_profile"[[:space:]]*:[[:space:]]*"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"' || echo "balanced")
+```
+
+Default to "balanced" if not set.
+
+**Model lookup table:**
+
+| Agent | quality | balanced | budget |
+|-------|---------|----------|--------|
+| gsd-planner | opus | opus | sonnet |
+| gsd-plan-checker | sonnet | sonnet | haiku |
+
+Store resolved models for use in Task calls below.
+</step>
+
 <step name="check_active_session">
 **First: Check for active UAT sessions**
 
@@ -389,6 +408,7 @@ Plans must be executable prompts.
 </downstream_consumer>
 """,
   subagent_type="gsd-planner",
+  model="{planner_model}",
   description="Plan gap fixes for Phase {phase}"
 )
 ```
@@ -434,6 +454,7 @@ Return one of:
 </expected_output>
 """,
   subagent_type="gsd-plan-checker",
+  model="{checker_model}",
   description="Verify Phase {phase} fix plans"
 )
 ```
@@ -474,6 +495,7 @@ Do NOT replan from scratch unless issues are fundamental.
 </instructions>
 """,
   subagent_type="gsd-planner",
+  model="{planner_model}",
   description="Revise Phase {phase} plans"
 )
 ```