Create a new signing keypair for API digital signatures. Supports ED25519 (recommended) or RSA ciphers. IMPORTANT: Save the private key immediately as eBay does not store it.
AI agents use ebay_create_signing_key to create or update resources in Ebay — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Ebay environment.
This tool creates and modifies API authentication credentials (a signing keypair), which is a Write operation that produces reversible changes to the system's security configuration. While the private key generation has security implications, the action itself is reversible (keys can be revoked/deleted).
From the tool's definition Tool creates a new signing keypair and generates credentials that must be saved immediately. Description explicitly states 'Create a new signing keypair' and warns 'Save the private key immediately as eBay does not store it,' indicating persistent creation of…
Documented attack patterns abuse exactly the kind of access ebay_create_signing_key gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Ebay, and nothing reaches the server without passing your rules. This is the rule we recommend for ebay_create_signing_key:
{
"version": "1",
"default": "deny",
"tools": {
"ebay_create_signing_key": {
"limits": [
{
"counter": "ebay_create_signing_key_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}ebay_create_signing_key stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Create a new signing keypair for API digital signatures. Supports ED25519 (recommended) or RSA ciphers. IMPORTANT: Save the private key immediately as eBay does not store it. It is categorised as a Write tool in the Ebay MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Ebay MCP server in PolicyLayer and add a rule for ebay_create_signing_key: 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 Ebay. Nothing to install.
ebay_create_signing_key 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 ebay_create_signing_key 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 ebay_create_signing_key. 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.
ebay_create_signing_key is provided by the Ebay MCP server (yosefhayim/ebay-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 332 Ebay tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
332 Ebay tools catalogued and risk-classified — across an index of 42,500+ MCP servers.