| name | cost-routing-discipline |
| description | Use when starting any new task to select the right GSD mode (fast/quick/plan-phase) and the right model tier (Haiku/Sonnet/Opus) for subagents — prevents 5-10× cost overpay on routine work |
Cost Routing Discipline
Why this skill exists
Default Anthropic UI sends everything to Opus 4.7 + max effort. This is correct for architecture but 5-10× overpay for grep, file-search, and routine coding. Without discipline, monthly cost is $300-500 for a solo dev. With discipline, same work costs $50-100.
When this skill activates
- Before invoking
/gsd-* commands — match mode to task risk
- Before dispatching subagents — match model to task type
- When user describes a task — auto-route based on keywords
Mode selection
Task Mode
─────────────────────────────────────────────────────────────
Trivial (typo, 1 line, doc update) → /gsd-fast
Small feature (<100 LOC, single concern) → /gsd-quick
Big feature (auth, payments, public API) → /gsd-plan-phase
Breaking change / migration → /gsd-plan-phase + /council
Trigger keywords (force-route)
| Keyword | Auto-route to |
|---|
| "опечатка", "typo", "одна строчка" | /gsd-fast |
| "обновить доку", "doc update" | /gsd-fast |
| "добавить тест", "add test" | /gsd-quick |
| "новый endpoint", "new endpoint" | /gsd-quick (small) or /gsd-plan-phase (with auth) |
| "auth", "payments", "schema migration" | /gsd-plan-phase + /council (always) |
Subagent model routing
When dispatching subagents (via better-model installed):
Task type Model Effort
──────────────────────────────────────────────────────────────────
Search / grep / pattern match → Haiku 4.5 (no effort)
Implementation / coding (1-2 files) → Sonnet 4.6 medium
Test writing → Sonnet 4.6 medium
Single-file debug → Sonnet 4.6 medium
Multi-file refactor (3+) → Opus 4.7 xhigh
Cross-file debug → Opus 4.7 xhigh
Architecture design → Opus 4.7 max
Security audit → Opus 4.7 max
Code review → Opus 4.7 xhigh (max overthinks)
Novel algorithm → Opus 4.7 max
Haiku does not accept the effort field (better-model v0.7.0+
warns on haiku+effort combos and treats haiku-no-effort as
correct). Do not pass effort to Haiku — it is rejected upstream.
Observability — better-model stats
better-model v0.8.0+ ships a read-only better-model stats CLI
subcommand for cost / routing analysis. Run after a heavy session to
see per-tier token spend, route hit rates, and which Sonnet/Haiku
calls escalated to Opus. Use to validate that your routing rules
above are actually saving the predicted 5-10× cost.
better-model stats
better-model stats --since 7d
Toolkit-pinned better-model version is now v0.8.1
(manifest.vendor_pins.better-model).
Edit operations
If Serena MCP installed (look for mcp__serena__* tools):
- Use Serena's symbol-level operations (
replace_symbol_body,
insert_before_symbol, insert_after_symbol, rename_symbol) for
refactoring — local LSP, no network round-trips, dramatically fewer
tokens than full-file rewrites
- Use native Edit for plain-text single-line changes
Morph Fast Apply was removed in v6.1 (no public source repo for the SDK,
paid SaaS with no privacy guarantee). There is no plug-and-play
equivalent — native Edit covers ~95% of cases honestly.
Discovery operations
"find function/symbol/all callers of foo" → Serena (mcp__serena__*)
"find code that does X" semantically → claude-context MCP (>100k LOC)
exact-string search → ripgrep
small project (<10k LOC) → ripgrep + Read
big project (>100k LOC) + frequent queries → claude-context MCP
Budget reality check
Track via Anthropic Console → Usage:
≤ $100/mo → use any mode freely
$100-300/mo → default to /gsd-quick for ~70% of work
$300-500/mo → force /gsd-fast for trivial; /gsd-quick mid-tier
> $500/mo → STOP. Audit last week's transcripts. Likely retrying same task multiple times.
Anti-patterns
- ❌ Using
/gsd-plan-phase for typo fixes (waste $4 per typo)
- ❌ Sending grep tasks to Opus (waste 5× on each search)
- ❌ Using native Edit when Morph available (waste 10× on each edit)
- ❌ "Just one more iteration" — if cost >$10 on single task, root-cause why
- ❌ Avoiding
/gsd-plan-phase on auth/payments to save money (wrong place to cheap out)
When NOT to optimize
Pay full price for:
- Security-relevant changes (auth, crypto, file uploads)
- Payment processing
- Public API breaking changes
- Database migrations on prod data
- Multi-week features touching 10+ files
Cost discipline ≠ cheaping out on high-stakes work.
Cross-references
components/cost-discipline.md — full cost layer breakdowncomponents/external-tools-recommended.md — Morph + better-model installrules/cost-discipline.md — auto-load trigger keywordsscripts/setup-cost-routing.sh (PR 5) — better-model installer
