Three terminal coding agents, three different philosophies, three different price points. Reasonix optimizes for cost with DeepSeek’s cache system. Grok Build brings multi-agent parallelism with xAI’s models. Claude Code delivers premium model quality from Anthropic.

Each is locked to its respective model provider (with one exception). Each has a different architecture. And the pricing gap between them is enormous.

I’ve used all three on production projects. Here’s the complete breakdown.

Three-Way Comparison Table

Feature	Reasonix	Grok Build	Claude Code
Model provider	DeepSeek only	xAI (Grok) + OpenRouter	Anthropic only
Default model	V4-Flash	Grok	Claude Sonnet 4
Premium model	V4-Pro (/pro command)	Any via OpenRouter	Claude Opus 4
Architecture	Single agent, cache-optimized	Multi-agent (parallel subagents)	Single agent (sequential)
Pricing	~$12 per 435M tokens	$99/mo SuperGrok or ~$1/1M tokens	$20/mo Pro or $3/$15 per 1M
Cache optimization	99.82% hit rate	Standard	Standard
License	MIT (open source)	Closed source	Closed source
Language	TypeScript	Go	Closed
Install	npm install -g reasonix	brew install grok-build	npm install -g @anthropic-ai/claude-code
Plan mode	Yes	Yes (/plan)	Yes (with flag)
MCP support	Yes	Yes	Yes
Memory	Built-in persistent	Session-based	CLAUDE.md + session resume
Web search	Built-in	Built-in	Via MCP
Hooks/automation	Skills + hooks	Skills + hooks	Hooks + custom commands
Multi-file parallel	No	Yes (subagents)	No
Desktop app	Yes	No	VS Code extension
Headless/CI	Yes	Yes (-p flag)	Yes (—print flag)
Maturity	Growing (9K stars)	Early beta (May 2026)	Production-stable (2025+)
Node requirement	>= 22	N/A (Go binary)	>= 18

Pricing Deep Dive

This is where the three tools diverge most dramatically. Let’s look at real usage scenarios.

Monthly cost by usage level

Usage level	Reasonix	Grok Build (API)	Grok Build (SuperGrok)	Claude Code (API)	Claude Code (Pro)
Light (50M tokens/mo)	~$1.40	~$50	$99/mo	~$75-150	$20/mo
Moderate (200M tokens/mo)	~$5.50	~$200	$99/mo	~$300-600	$20/mo (rate limited)
Heavy (500M tokens/mo)	~$13.80	~$500	$99/mo	~$750-1,500	$100/mo Max
Team of 5, heavy	~$69/mo	~$2,500 or $495/mo	$495/mo (5 seats)	~$3,750-7,500 or $500/mo	$500/mo (5 Max seats)

The pattern is clear:

• Reasonix is cheapest at every usage level due to cache optimization
• Grok Build’s SuperGrok is a flat rate that benefits heavy users
• Claude Code’s Pro is cheap for light users but rate-limits heavy ones
• API pricing for both Grok Build and Claude Code scales linearly and gets expensive fast

For the math behind DeepSeek’s pricing advantage, see DeepSeek V4-Pro’s permanent 75% discount.

Cost per equivalent task

A typical feature implementation (create endpoint, write tests, update docs) uses roughly 5-10M tokens across the full session.

Task	Reasonix	Grok Build	Claude Code
Single feature	$0.14-0.28	$5-10	$15-30 (API)
Bug fix session	$0.05-0.10	$2-5	$5-15 (API)
Large refactor	$0.50-1.00	$15-30	$45-90 (API)

Reasonix is 50-100x cheaper than Claude Code on API pricing for equivalent work. Even against Grok Build, it’s 20-50x cheaper.

Agent Architecture

Reasonix: Cache-First Single Agent

Reasonix runs a single agent optimized around DeepSeek’s caching system. Every prompt is structured to maximize cache reuse. The context window builds up across turns, and because cached tokens are cheap and fast, Reasonix can maintain large contexts without cost concerns.

This means:

• Long sessions get cheaper per turn (more cache hits)
• Context doesn’t need aggressive pruning
• Responses are faster on subsequent turns
• No coordination overhead between agents

Grok Build: Multi-Agent Parallelism

Grok Build uses a coordinator that spawns parallel subagents for complex tasks. A feature that touches 6 files might run 3 subagents simultaneously, each handling a subset.

This means:

• Complex multi-file tasks complete faster
• Coordination overhead on simple tasks
• Potential for conflicting changes between subagents
• Higher token usage (multiple agents = multiple contexts)

Claude Code: Sequential Single Agent

Claude Code processes tasks sequentially with one agent maintaining full context. It reads, reasons, acts, and verifies in a single thread.

This means:

• Predictable, easy to follow
• Best for deep sequential reasoning
• Slower on large multi-file changes
• No coordination issues

For complex debugging or architectural decisions, Claude Code’s sequential approach often produces better results. For bulk multi-file changes, Grok Build’s parallelism is faster. For cost-sensitive iterative development, Reasonix wins.

Model Lock-In

Tool	Lock-in level	Can use other models?
Reasonix	Full (DeepSeek only)	No
Grok Build	Partial (defaults to Grok, supports OpenRouter)	Yes
Claude Code	Full (Anthropic only)	No

Grok Build is the only one with model flexibility. You can route to Claude, GPT-4, DeepSeek, or any OpenRouter model. This is a genuine advantage if you want one tool that works with multiple providers.

Reasonix and Claude Code are both locked to their respective providers. The tradeoff: lock-in enables deeper optimization. Reasonix’s cache system only works because it’s built specifically for DeepSeek’s API. Claude Code’s tight integration with Anthropic’s models enables features that wouldn’t work with generic model routing.

MCP Support

All three support MCP (Model Context Protocol) servers, but the ecosystems differ:

Claude Code has the largest MCP ecosystem. It’s been around longest and Anthropic actively promotes MCP. Hundreds of community servers available.

Grok Build supports MCP plus its own Skills Marketplace. You get both MCP compatibility and xAI’s curated skill system.

Reasonix supports MCP servers. The ecosystem is smaller but growing. Most popular MCP servers (filesystem, git, database) work fine.

If MCP ecosystem breadth is critical, Claude Code leads. For practical use (the 10-20 MCP servers most developers actually use), all three work.

Open Source

Tool	License	Source available	Community contributions
Reasonix	MIT	Yes (GitHub, 9K stars)	Yes
Grok Build	Closed	No	No
Claude Code	Closed	No	No

Reasonix is the only open source option. This matters for:

• Security audits (you can read the code)
• Enterprise compliance (MIT is permissive)
• Customization (fork and modify)
• Trust (verify what it does with your code)
• Longevity (community can maintain if company pivots)

If open source is a requirement, Reasonix is your only choice among these three.

Feature Matrix

What each does best

Reasonix excels at:

• Cost-efficient iterative development
• Long coding sessions (cache compounds)
• Persistent memory across sessions
• Built-in web search without MCP setup

Grok Build excels at:

• Large multi-file changes (parallel subagents)
• Model flexibility (switch models per task)
• Skills marketplace for reusable workflows
• Flat-rate pricing for heavy users ($99/mo)

Claude Code excels at:

• Complex reasoning and architectural decisions
• Deep sequential debugging
• Largest MCP ecosystem
• Production stability and maturity

What each lacks

Reasonix lacks:

• Model flexibility (DeepSeek only)
• Multi-agent parallelism
• Deep git integration
• Maturity of longer-running tools

Grok Build lacks:

• Cost efficiency (no cache optimization)
• Open source transparency
• Production stability (early beta)
• Desktop app

Claude Code lacks:

• Cost efficiency (most expensive option)
• Model flexibility (Anthropic only)
• Open source transparency
• Multi-agent parallelism
• Built-in web search

Setup Comparison

# Reasonix
npm install -g reasonix
export DEEPSEEK_API_KEY=your-key
reasonix code

# Grok Build
brew install grok-build  # or: go install github.com/xai/grok-build@latest
export XAI_API_KEY=your-key
grok code

# Claude Code
npm install -g @anthropic-ai/claude-code
export ANTHROPIC_API_KEY=your-key
claude

All three are quick to install. Reasonix and Claude Code use npm. Grok Build uses Go binaries or Homebrew. All require their respective API keys.

Verdict: Which Should You Use?

Choose Reasonix if:

• Budget is your primary constraint
• You’re happy with DeepSeek’s model quality
• Open source matters to you
• You do lots of iterative coding sessions
• You want the lowest possible cost per token

Choose Grok Build if:

• You need model flexibility (use any model)
• Your work involves large parallel multi-file changes
• You’re already paying for SuperGrok ($99/mo)
• You want the Skills marketplace
• You’re comfortable with beta software

Choose Claude Code if:

• You need the best model quality available
• Complex reasoning and debugging are your primary tasks
• Stability and maturity are non-negotiable
• You rely on the MCP ecosystem heavily
• You’re already in Anthropic’s ecosystem

The optimal setup for a cost-conscious team:

1. Reasonix for 80% of daily coding (cheap, fast, good enough)
2. Claude Code for the 20% that needs premium reasoning (complex bugs, architecture)
3. Skip Grok Build unless you specifically need multi-agent parallelism

The optimal setup for a “best tool for each job” team:

1. Claude Code for complex reasoning tasks
2. Grok Build for large parallel refactors
3. Reasonix for high-volume iterative work

For a broader comparison of terminal coding agents including Codex CLI and Antigravity, see our Antigravity 2 vs Claude Code vs Codex CLI comparison.

FAQ

Which produces the best code quality?

Claude Code, due to Claude Sonnet 4 and Opus 4’s superior reasoning capabilities. Grok Build with Grok models is second. Reasonix with DeepSeek V4-Flash is third for complex tasks, but the gap narrows significantly for standard coding work. Using Reasonix’s /pro command for V4-Pro brings it closer to Claude quality.

Can I use all three on the same project?

Yes. They don’t conflict. Each uses its own configuration (Reasonix has memory, Grok Build reads CLAUDE.md, Claude Code reads CLAUDE.md). You can switch between them freely.

Which is most stable for production use?

Claude Code. It’s been in production since early 2025 and is the most battle-tested. Reasonix is stable but newer. Grok Build is early beta and not recommended as a sole production tool yet.

Is the cost difference really that large?

Yes. For 435M tokens: Reasonix costs ~$12, Grok Build costs ~$435 (API) or is included in $99/mo SuperGrok, Claude Code costs ~$1,300-6,500 (API). The cache optimization creates an order-of-magnitude difference.

Which has the best MCP support?

Claude Code has the largest ecosystem. All three support the MCP protocol, so most servers work with any of them. The difference is community size and number of pre-built integrations.

Should I pick based on model quality or cost?

Depends on your work. If you’re doing standard feature development, tests, and refactoring (most coding work), model quality differences are minimal and cost should drive the decision. If you’re doing complex architectural work or debugging subtle issues, Claude’s model quality justifies the premium.

Can Grok Build use DeepSeek models?

Yes. Through OpenRouter model routing, you can point Grok Build at DeepSeek models. However, you won’t get Reasonix’s cache optimization, so you’ll pay standard DeepSeek rates. If you want DeepSeek with cache optimization, use Reasonix directly.

Which is best for a solo developer on a budget?

Reasonix. At ~$11/month for moderate usage, it’s cheaper than a Netflix subscription. Claude Code’s $20/month Pro plan is the next cheapest option but rate-limits heavy users. Grok Build’s $99/month is hard to justify for a solo developer unless you use other xAI products.

Do any of these work without internet?

No. All three require API connections to their respective model providers. For offline coding assistance, you’d need a local model setup with a tool like Aider or Ollama.