Circuit & Chisel

Circuit & Chisel raised $19.2 million in a seed round in September 2025.

The round was co-led by Primary Venture Partners and ParaFi Capital, with participation from Stripe, Coinbase Ventures, Solana Ventures, Samsung Next, and Polygon Labs. Notable angel investors include Solana founders Anatoly Yakovenko and Raj Gokal, former Amazon and PepsiCo board member Edith Cooper, Google Cloud's Rich Widmann, Figure's Michael Tannenbaum, and Kraken's Arjun Sethi.

Circuit & Chisel is the company behind ATXP, a payments protocol that enables AI agents to autonomously pay for tools and services across the web without human intervention or traditional API key management. Think of it as HTTP for agent commerce—where HTTP enables browsers to request web pages, ATXP enables agents to discover, purchase, and use paid services in real-time.

The protocol works through the Model Context Protocol (MCP), an emerging standard for how AI agents communicate with external tools. Developers install the ATXP client library and give their agent a wallet on chains like Base, Solana, or Polygon. When the agent needs a service—like scraping a LinkedIn profile or accessing a paywalled article—it calls the tool through an MCP server with a signed payment payload.

The MCP server's ATXP middleware verifies the payment, executes the tool, and returns the result instantly. Payments are settled in stablecoins like USDC, enabling sub-cent micropayments that would be impossible with traditional credit card rails.

For tool providers, monetizing becomes as simple as adding one line of code to set a price per API call. Funds land directly in their wallet without billing systems, user accounts, or API key rotation. The protocol includes a discovery layer where agents can programmatically find and pay for tools as they reason through tasks.

ATXP supports nested payments, meaning an agent can pay on behalf of a user or another agent, creating complex delegation chains. All transactions are auditable on-chain, and signed payments double as authentication, eliminating the security risks of long-lived API keys.

Circuit & Chisel operates as a B2B infrastructure company building the foundational payments layer for autonomous AI agents. The business model centers on protocol adoption rather than direct software sales.

Revenue comes primarily from transaction fees—a small percentage take-rate on payments flowing through ATXP. This creates a network effect where more agents using the protocol generates more transaction volume and revenue.

The company also plans SaaS-style recurring revenue from enterprises that want to host paid MCP tools on the platform. These customers pay monthly fees for enhanced features like analytics, rate limiting, and enterprise-grade security controls.

Developer adoption follows a freemium model with usage-based pricing tiers. Free plans support basic functionality, while paid tiers unlock higher transaction limits, advanced tooling, and priority support.

The protocol leverages existing blockchain infrastructure for settlement, keeping capital requirements low. ATXP acts as an orchestration layer that routes payments across multiple chains and stablecoin types, avoiding the need to build proprietary payment rails.

Gross margins should be high since the core product is software, though the company will have pass-through costs from blockchain transaction fees. The model scales efficiently as protocol adoption grows without proportional increases in operational overhead.

Coinbase's x402 protocol represents the most direct competitive threat, having launched with over 60 partners and integration into Google's Agentic Payments Protocol. X402 benefits from Coinbase's exchange relationships and mainstream crypto adoption, creating significant network effects that could make it the default standard.

Google's AP2 protocol adds payments extensions to agent-to-agent communication and officially supports x402 as a plugin. Google's cloud distribution and Android ecosystem could commoditize the payments layer and force specialized protocols into niche use cases.

Open-source alternatives like h402 aim to fragment the market by supporting any token rather than just USDC, positioning themselves as more decentralized options that could appeal to crypto-native developers.

Stripe's Agent Toolkit provides fine-grained spending controls and order management APIs while leveraging Stripe's existing merchant network. As both an investor in Circuit & Chisel and a potential competitor, Stripe could eventually build competing functionality or acquire the company.

Visa's Intelligent Commerce platform exposes VisaNet to agent developers and partners with major AI companies. Visa's brand trust and fraud prevention capabilities appeal to enterprises wary of cryptocurrency-based solutions.

Traditional payment processors like PayPal and Square are adding agent-ready APIs to their existing infrastructure, potentially offering lower-friction adoption paths for businesses already using their services.

Major agent frameworks like LangChain, AutoGen, and CrewAI could build native payment capabilities directly into their platforms, bypassing external protocols entirely. These frameworks have large developer communities and could bundle payments with other agent services.

Cloud providers like AWS, Google Cloud, and Microsoft Azure might integrate payment functionality into their AI and machine learning services, creating vertically integrated stacks that compete with standalone protocols.

Beyond the core ATXP protocol, Circuit & Chisel can build a comprehensive developer platform with SDKs, testing sandboxes, and observability tools. This would expand the addressable market from protocol users to every development team building autonomous agents.

An agent commerce API gateway that automatically translates standard HTTP 402 responses into ATXP transactions could capture value from every enterprise exposing agent-payable endpoints. This managed service would handle escrow, retries, and receipt logging.

Analytics and reputation services layered on top of ATXP payment metadata could create high-margin subscription revenue. As agent-to-agent transactions proliferate, counterparties will need fraud scores, SLA guarantees, and dispute resolution mechanisms.

Early adopters are crypto-native developers, but enterprise AI teams at banks and large corporations represent a massive expansion opportunity. Packaging ATXP for on-premises deployment could unlock Fortune 500 budgets while addressing compliance requirements around public blockchain usage.

Every API provider, SaaS vendor, and data broker could adopt ATXP to eliminate subscription friction and enable usage-based pricing. This multiplies the downstream addressable market without requiring direct sales into each vertical.

Government and defense applications present another expansion vector, particularly as agencies explore autonomous systems for logistics, intelligence, and operations that require secure, auditable payment capabilities.

Stablecoin-denominated micropayments make ATXP inherently cross-border, enabling expansion into regions where traditional payment rails are expensive or unreliable. Adding support for local stablecoins and regional blockchain networks could accelerate adoption in Asia-Pacific and Latin American markets.

Partnerships with local fintech companies and blockchain infrastructure providers could facilitate regulatory compliance and market entry in jurisdictions with specific cryptocurrency regulations.

The protocol's ability to handle microtransactions makes it particularly valuable in emerging markets where mobile payments and small-value transactions dominate digital commerce patterns.

Protocol adoption: ATXP's success depends entirely on widespread adoption by agent developers and tool providers, creating a classic chicken-and-egg problem where both sides need the other to exist before seeing value. If competing protocols like Coinbase's x402 achieve critical mass first, Circuit & Chisel could be relegated to niche use cases regardless of technical superiority.

Regulatory uncertainty: Cryptocurrency-based payment protocols face evolving regulatory scrutiny that could limit enterprise adoption or require costly compliance infrastructure. Changes in stablecoin regulations or blockchain transaction rules could fundamentally alter the economics of micropayments and force expensive platform modifications.

Big tech integration: Major cloud providers and AI platforms could build competing payment functionality directly into their services, bypassing external protocols entirely. If companies like Google, Microsoft, or OpenAI integrate payments into their agent frameworks, standalone protocols may struggle to maintain relevance outside of specialized use cases.