Approve another address to spend tokens on behalf of the owner. This is used for allowing another address (like a contract) to transfer your tokens. Requires token contract address, spender address, and amount as input. Returns the transaction hash upon successful approval.
Handles credentials or secrets (private_key)
Part of the COTI MCP Server MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents use approve_erc20_spender to create or modify resources in COTI MCP Server. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call approve_erc20_spender repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach COTI MCP Server.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
tools:
approve_erc20_spender:
rules:
- action: allow
rate_limit:
max: 30
window: 60See the full COTI MCP Server policy for all 44 tools.
Agents calling write-class tools like approve_erc20_spender have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.
Approve another address to spend tokens on behalf of the owner. This is used for allowing another address (like a contract) to transfer your tokens. Requires token contract address, spender address, and amount as input. Returns the transaction hash upon successful approval.. It is categorised as a Write tool in the COTI MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Add a rule in your Intercept YAML policy under the tools section for approve_erc20_spender. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the COTI MCP Server MCP server.
approve_erc20_spender is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the approve_erc20_spender rule in your Intercept 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 Intercept policy for approve_erc20_spender. 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.
approve_erc20_spender is provided by the COTI MCP Server MCP server (davibauer/coti-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic policy on every MCP tool call. Per-identity grants. Full audit log.