flash_balances
Fetch native and token balances for a wallet, using the built-in per-chain public RPCs (or configured overrides) — no external RPC lookup needed. Defaults to the configured funder wallet. Read-only; works without an API key. Omitting tokens lists every token the wallet holds: SPL tokens on Solana...
This record as markdown: /tools/definitive-fi-flash-mcp/flash-balances.md
What flash_balances does on Flash
AI agents call flash_balances to retrieve information from Flash without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
chain | string | Yes | |
rpcUrl | string | — | Override the RPC endpoint for this call |
tokens | array | — | Token addresses (EVM) or mints (Solana) to include |
address | string | — | Wallet address (defaults to the configured funder wallet for this chain) |
Parameters from the server's own tool schema.
Why flash_balances is rated Low
This tool retrieves and queries wallet balance data with no side effects, modifications, or irreversible actions. It is a pure read operation that queries blockchain state. The presence of related financial tools (flash_submit_order, flash_cancel_order) on the same server does not change the classification of this specific tool, which is strictly informational.
From the tool's definition Tool description explicitly states "Fetch native and token balances for a wallet" and "Read-only; works without an API key." The description emphasizes it retrieves balance information without modifying state.
Risk signalsBulk/mass operation — affects multiple targets
Attacks that exploit this kind of access
The rule that runs flash_balances safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Flash, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For flash_balances, this is the rule to start with:
flash_balances is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Flash, apply this rule, and every flash_balances call is checked against it from then on.
Questions about flash_balances
Fetch native and token balances for a wallet, using the built-in per-chain public RPCs (or configured overrides) — no external RPC lookup needed. Defaults to the configured funder wallet. Read-only; works without an API key. Omitting tokens lists every token the wallet holds: SPL tokens on Solana, and ERC-20s on EVM chains that have a block explorer configured (auto-discovered, then read live on-chain). Pass explicit tokens to query specific addresses, or on EVM chains without explorer support (only the native balance is returned otherwise). It is categorised as a Read tool in the Flash MCP Server, which means it retrieves data without modifying state.
flash_balances accepts 4 parameters: chain, rpcUrl, tokens, address. Required: chain. The full parameter table on this page comes from the server's own tool schema.
Register the Flash MCP server in PolicyLayer and add a rule for flash_balances: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Flash. Nothing to install.
flash_balances is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the flash_balances rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for flash_balances. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
flash_balances is provided by the Flash MCP server (@definitive-fi/flash-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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