read_contract_state
Read the current on-chain value of a view/pure function. Fetches from the chain (cached 60s) and returns the decoded output. Accepts slug or chain+address.
This record as markdown: /tools/defi-io-smartcontract/read-contract-state.md
What read_contract_state does on Smarts Md
AI agents call read_contract_state to retrieve information from Smarts Md 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 |
|---|---|---|---|
args | array | — | Positional arguments for the function, in ABI order. Addresses as 0x hex strings, integers as integers. Default: [] |
slug | string | — | Curated slug like 'uni-eth'. Alternative to chain+address. |
chain | string | — | Chain slug: eth, base, arbitrum, optimism, or polygon. Required unless `slug` is given. |
address | string | — | The 0x-prefixed contract address. Required unless `slug` is given. |
function_name | string | — | ABI function name, e.g. 'totalSupply' or 'balanceOf'. |
Parameters from the server's own tool schema.
Why read_contract_state is rated Low
This tool retrieves data from smart contracts without any capability to modify, execute transactions, or trigger state changes. View and pure functions are read-only by definition in Solidity. The 60-second caching and decoding of outputs are standard for blockchain data queries. No financial transactions, code execution, or data destruction are possible.
From the tool's definition Tool description explicitly states "Read the current on-chain value" and "returns the decoded output". The name "read_contract_state" and function signature indicate query-only access to view/pure functions with no state modification.
Attacks that exploit this kind of access
The rule that runs read_contract_state safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Smarts Md, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For read_contract_state, this is the rule to start with:
read_contract_state 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 Smarts Md, apply this rule, and every read_contract_state call is checked against it from then on.
Questions about read_contract_state
Read the current on-chain value of a view/pure function. Fetches from the chain (cached 60s) and returns the decoded output. Accepts slug or chain+address. It is categorised as a Read tool in the Smarts Md MCP Server, which means it retrieves data without modifying state.
read_contract_state accepts 5 parameters: args, slug, chain, address, function_name. The full parameter table on this page comes from the server's own tool schema.
Register the Smarts Md MCP server in PolicyLayer and add a rule for read_contract_state: 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 Smarts Md. Nothing to install.
read_contract_state 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 read_contract_state 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 read_contract_state. 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.
read_contract_state is provided by the Smarts Md MCP server (defi-io/smartcontract). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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