Yes, a non-human agent can use a paid endpoint to read Solana mainnet balances through BuildAWallet. The platform provides a machine-native API that allows autonomous agents to query live on-chain data without human intervention. This guide covers the authentication flow, the specific Solana endpoints available, and how to integrate these tools into your agent workflow using Model Context Protocol (MCP) or standard REST calls.

BuildAWallet operates on a prepaid unit model for machine access. A prepaid API plan is a subscription that grants an agent a specific number of API units for a 30-day period. Agents do not pay per transaction on the blockchain for every read; instead, they deduct units from their account balance. This model ensures that agents can perform high-frequency data retrieval without the latency and cost of on-chain gas fees for simple reads. For additional details, review the BuildAWallet Human or machine.

The platform offers three primary tiers for machine access. The Starter plan provides 100,000 API units, the Pro plan offers 500,000 units, and the Scale plan provides 2,000,000 units. Unused units roll over when you renew before the expiry date. For agents that require sporadic access, a metered pay-per-use option is available at $0.01 per request, requiring a minimum balance of $1. This flexibility allows developers to choose between bulk prepaid capacity and on-demand metering based on their agent's operational frequency.

Agent Balance Queries

Agent balance queries are HTTP requests that return the current token holdings of a specific wallet address. BuildAWallet supports queries for native assets and stablecoins across ten mainnets, including Solana. When an agent calls a balance endpoint, the system performs the necessary chain work to retrieve the data. Read units are charged only after the chain work succeeds, ensuring that agents are not billed for failed or rejected requests.

For Solana, the agent can query the native SOL balance or specific stablecoin balances like USDC. The API returns the data in a structured JSON format that is easy for LLMs and autonomous scripts to parse. This direct access to mainnet data allows agents to make real-time decisions based on actual on-chain state rather than cached or delayed data.

Solana RPC Endpoints

Solana RPC endpoints are the underlying infrastructure that allows nodes to communicate with the Solana network. BuildAWallet abstracts this complexity by providing a unified API layer. Instead of managing multiple RPC providers or handling rate limits from public endpoints, agents interact with BuildAWallet's stable API. This abstraction ensures consistent performance and reliability for balance checks and transaction status updates.

The platform supports Solana as one of its ten primary networks. Agents can use the specific Solana endpoints to check balances, verify transaction confirmations, and retrieve portfolio snapshots. By centralizing these calls, BuildAWallet reduces the operational overhead for agent developers who would otherwise need to maintain complex RPC connection logic.

API Key Authentication

API key authentication is the method by which agents prove their identity and entitlement to access paid endpoints. Agents must include their API key in the Authorization header of every request. The key format typically begins with a specific prefix, such as baw_acct_ for account keys or baw_live_ for live session keys. This key is generated after the agent completes the payment and verification process.

Free endpoints, such as listing available chains or plans, do not require an API key. However, any endpoint that returns live on-chain data, such as balances or transaction details, requires a valid key. The system validates the key against the agent's account to ensure that the agent has sufficient units remaining. If the key is invalid or the units are exhausted, the request will be rejected, and the agent will receive an appropriate error code.

Agent Access to Solana Balances: BuildAWallet Paid API Guide

Agent RPC Endpoints

Agent RPC endpoints are the specific URL paths that agents use to interact with the blockchain data. BuildAWallet provides a set of RESTful endpoints under the /machine/v1/ path. These endpoints are designed to be machine-readable and are documented in the OpenAPI 3.1 specification. Agents can discover these endpoints through the /llms.txt file or the /.well-known/agent.json manifest, which are standard machine-readable entry points.

The endpoints are categorized by function. Wallet endpoints handle creation and validation, while chain-specific endpoints handle data retrieval. For Solana, the agent would use the /machine/v1/solana/ path prefix to access Solana-specific data. This structured approach allows agents to programmatically discover and utilize the correct endpoints without hardcoding complex URL structures.

Solana Balance Queries

Solana balance queries are specific requests to retrieve the amount of SOL or other tokens held by an address. The primary endpoint for this is GET /machine/v1/solana/wallet/{address}. This endpoint returns the live native balance on the Solana network. Each call consumes one API unit. For a more comprehensive view, agents can use the portfolio endpoint, which queries native and stablecoin balances across all supported networks in a single call, also consuming one unit.

Agents can also query specific stablecoin balances using the /machine/v1/solana/stablecoin/{address} endpoint. This is useful for agents that manage USDC or other stable assets on Solana. The response includes the balance in the smallest unit of the token, which agents can then convert to human-readable formats. These queries are critical for agents that need to verify funds before executing transactions or making financial decisions.

Paid endpoint authentication involves the initial setup process where an agent proves control of a wallet and pays for access. The process begins with a signed challenge. The agent signs a one-use message with a supported subscription wallet, such as a Base or Solana wallet. This signature is submitted to the /machine/v1/auth/verify endpoint to receive a 30-day session token.

Once the session token is obtained, the agent can confirm the payment by submitting the exact quoted payment transaction. After verification, the agent mints a baw_live_ API key. This key replaces any previous key and grants access to the paid endpoints. The entire process is designed to be fully automated, allowing agents to discover, pay, and authenticate without human checkout. This machine-native flow is a core feature of BuildAWallet's agent infrastructure.

Key Takeaways

  • BuildAWallet allows non-human agents to read Solana mainnet balances via paid API endpoints.
  • Prepaid plans offer 100,000 to 2,000,000 API units for 30 days, with unused units rolling over.
  • Metered access is available at $0.01 per request for agents with sporadic usage.
  • Agents must authenticate using an API key in the Authorization header for paid calls.
  • The platform supports ten mainnets, including Solana, with unified endpoints for balances and transactions.
  • Machine-native discovery is enabled via /llms.txt and /.well-known/agent.json manifests.
  • Read units are charged only after successful chain work, preventing billing for failed requests.
  • The authentication flow uses signed challenges to verify wallet control and issue session tokens.

Frequently Asked Questions

Can an agent pay for API access without a human?

Yes. BuildAWallet supports a machine payment flow where agents can discover plans, create or bring a wallet, sign a challenge, and pay the quoted asset amount on a supported network. The agent then receives a machine API credential automatically.

Which networks are supported for balance queries?

BuildAWallet supports ten mainnets, including Solana, Base, Ethereum, and Bitcoin. Agents can query native and stablecoin balances on any of these networks using the unified API.

How much does a Solana balance query cost?

A single balance query consumes one API unit. If you are on a prepaid plan, this deducts one unit from your balance. If you are on metered access, it costs $0.01.

Do I need to manage RPC nodes myself?

No. BuildAWallet handles the underlying RPC connections and chain work. You interact with the BuildAWallet API, which abstracts the complexity of managing multiple RPC providers and rate limits.

How do I get an API key for my agent?

You must complete the authentication flow. This involves signing a challenge with a supported wallet, paying for a plan, and minting a baw_live_ API key. The key is then used in the Authorization header for subsequent requests.

Can I use the free tier to test Solana queries?

The free tier provides 1,000 free API units. However, live balance queries typically require a paid plan or metered access. Free endpoints are limited to discovery, such as listing chains and plans.

Conclusion

BuildAWallet provides a robust infrastructure for non-human agents to interact with Solana and other mainnets. By using the paid API endpoints, agents can retrieve live balance data, verify transactions, and manage portfolios with minimal overhead. The platform's machine-native design, including MCP support and automated payment flows, makes it an ideal choice for developers building autonomous financial agents. To start integrating these tools, visit the API explorer or review the pricing plans to select the capacity that fits your agent's needs.