Cut OpenClaw API Costs by Up to 90%: A Practical Multi-Model Strategy

One of the first challenges OpenClaw adopters encounter after deployment is API cost escalation. The default single-model configuration works well for quality, but has a structural weakness: every task—regardless of complexity—hits the primary model. Here’s how to achieve 80-90% cost reduction while preserving quality where it matters.

Why Default Configuration Becomes a Cost-Burning Machine

The core issue is architectural. Heartbeat checks, email triage, calendar lookups, and web searches all route to the primary model by default. If that’s Claude Opus 4.6 ($5 input / $25 output per million tokens), you’re paying premium rates for tasks that a $0.30 model handles equally well.

Several compounding factors amplify this:

• Session history growth: Mature sessions exceed 200,000 tokens
• System prompt repetition: SOUL.md, AGENTS.md, MEMORY.md (3,000–14,000 tokens) resend on every call
• Log accumulation: Browser snapshots and command output compound over time
• Heartbeat frequency: 30-minute intervals with Opus means 48 full-context API calls daily. 15-minute cron jobs: 96 calls, or $10–20/day

For heavy automation users, monthly costs can reach $300–600. The fix is deliberate model routing.

Three Reduction Approaches

1. Intelligent Routing: Match Model Capability to Task Complexity

The most direct approach routes tasks to appropriately-priced models based on complexity. OpenClaw supports per-function model assignment.

Three implementation methods:

• Keyword/regex matching for classification
• Intent classification using a cheap pre-router model
• Custom Python skill for advanced routing logic

Representative routing configuration:

Task Category	Appropriate Model	Reason
Heartbeat / Email check	Haiku / Gemini Flash	Routine, no creativity required
Code / Debugging	GPT-5.2-turbo / Sonnet 4.6	Reasoning precision needed
Strategy / Complex analysis	Opus 4.6	Deep thinking required
Image analysis	Gemini 2.5 Flash	Cost-performance advantage

2. Prompt Caching: The Most Underutilized Optimization

Both Anthropic and OpenAI automatically cache unchanged prompt sections. Yet most OpenClaw users don’t leverage this effectively.

Concrete impact:

• System prompts (3,000–14,000 tokens) billed at full rate every call → up to 90% discount with caching
• Setting heartbeat interval to 55 minutes ensures all calls hit warm cache

Haiku + caching combined calculation: Switching heartbeats from Opus (default) to Haiku with prompt caching enabled brings monthly heartbeat costs from $100+ down to approximately $0.50. For many users, this single change resolves the cost problem entirely.

3. Local Models: Drive Marginal Cost to Zero

For 24/7 heavy automation workflows, local models make economic sense. No API charges mean execution frequency becomes irrelevant from a cost perspective.

The current recommended choice for local deployment is Qwen 3 32B, which competes with Claude Sonnet 3.5 across many tasks. A single RTX 4090 delivers 40+ tokens/sec, and it connects directly to OpenClaw via Ollama.

ClawRouter: The Community’s Leading Cost Optimization Tool

The most rapidly-adopted tool in this space is ClawRouter, an OpenClaw-native skill that reached 2,400 GitHub stars within 11 days of release.

ClawRouter’s approach is straightforward: a local lightweight classifier analyzes each request and routes to one of four tiers based on complexity:

• Simple → Cheap models (DeepSeek, Gemini Flash, etc.)
• Medium → Mid-tier models
• Complex → Claude Sonnet 4.6
• Heavy → Claude Opus 4.6

Four profiles (Auto/Eco/Premium/Free) accommodate different use cases. The appeal is automation—no manual routing rules to maintain.

OpenRouter: 300+ Models Through One API

For users who don’t want to manage multiple provider APIs, OpenRouter provides a unified interface. Create a free account, add credits, update OpenClaw configuration, and gain access to 300+ models with automatic routing.

Best suited for users who want to use cost-effective models across providers without being locked into a single vendor.

Model Cost Reference

Key data points for planning your routing strategy:

Anthropic models (per million tokens):

• Claude Opus 4.6: $5 input / $25 output (maximum capability)
• Claude Sonnet 4.6: $3 input / $15 output (near-Opus performance)
• Claude Haiku: $0.25 input / $1.25 output (routine tasks)

High cost-performance alternatives:

• Gemini 2.5 Flash: Significant cost reduction with minimal quality loss
• MiniMax M2.5: 80.2% on SWE-Bench Verified, 10-20x cheaper than Opus 4.6
• Kimi K2.5: Best raw cost-performance ratio in current open model landscape

On Claude Max Plans

Some users have attempted workarounds using Claude Max subscription plans as API access through OpenClaw. Multiple reports of account bans for Anthropic ToS violations exist. This is not a supported use case and carries account risk.

Implementation Priority

Ordered by ease of implementation and immediate impact:

1. Switch heartbeats to Haiku + enable prompt caching (30 minutes of configuration, immediate effect)
2. Deploy ClawRouter (automatic routing without manual rule maintenance)
3. Adopt OpenRouter for multi-provider flexibility (expand model options)
4. Introduce local models for heavy automation (long-term fixed cost reduction)

Assessment

The majority of what an agent processes is routine work. Frontier models are genuinely needed for a minority of tasks—complex reasoning and creative judgment. Intelligent routing combined with caching makes 80-90% cost reduction realistic without degrading quality on the work that actually requires it.

For users experiencing OpenClaw cost pressure, the highest-leverage starting point is the simplest change: route heartbeats to a lightweight model and enable prompt caching. That alone resolves the majority of cases.

Reference Resources:

• ClawRouter GitHub: 2,400 stars in 11 days post-release
• OpenRouter: https://openrouter.ai
• Ollama: https://ollama.ai