MCP Specification: Tool Definitions and Authentication

This is the technical reference for the Inheribase MCP server v2.0. It covers the authentication protocol, full tool definitions with argument and return schemas, a JSON-RPC implementation example, and security best practices for integrators building on top of the Inheribase protocol.

Protocol authentication

Agents connecting via MCP must provide a valid API key in the INHERIBASE_API_KEY environment variable. Inheribase supports two key classes with different permission scopes:

Key type	Prefix	Access
Human-bound key	`sk_human_...`	Unrestricted access to the user’s vault
Scoped agent key	`sk_agent_...`	Restricted to specific tools like `check_in` and `store_asset`

Set the key in your MCP server environment before starting the server:

export INHERIBASE_API_KEY=sk_agent_your_key_here

Tool definitions

1. store_asset

Persists a file to the vault with client-side encryption. The file content is encrypted on the agent before it is transmitted to Inheribase. Arguments:

Name	Type		Description
`filename`	`string`	Required	The destination path in the vault
`data`	`string`	Required	Base64-encoded file content
`metadata`	`object`	Optional	Tags or descriptions for the asset

Returns:

Name	Type	Description
`hash`	`string`	The Arweave transaction ID
`timestamp`	`string`	The cryptographic anchoring time (ISO 8601)

2. check_status

Retrieves the current state of the vault and succession timeline. Arguments:

Name	Type		Description
`vaultId`	`string`	Optional	Defaults to the key’s primary vault

Returns:

Name	Type	Description
`state`	`string`	One of `active`, `releasing`, or `released`
`daysRemaining`	`number`	Days until the current trigger executes

3. check_in

Executes an Audit Pulse to reset the Dead Man’s Switch timer. This confirms the user is active and restarts the check-in countdown. Arguments:

Name	Type		Description
`note`	`string`	Optional	A brief log entry for the audit trail

Returns:

Name	Type	Description
`nextCheckInDue`	`string`	ISO timestamp of the next required Vitality Event

Implementation example

The following JSON-RPC payload demonstrates how to call the check_in tool from a compatible MCP client:

{
  "method": "tools/call",
  "params": {
    "name": "check_in",
    "arguments": {
      "note": "Daily automated status verification"
    }
  }
}

Security best practices

Never share sk_human_... keys. Use scoped sk_agent_... keys for shared or automated integrations. Human-bound keys grant unrestricted vault access and should only be used in fully controlled personal environments.
Handle 402 errors in store_asset calls. The MCP server returns a 402 status when the Vault Credits balance is insufficient to store a file. Build retry logic that checks for credits before attempting large uploads.
Review the audit trail regularly. All MCP actions are logged in your vault’s Activity Monitoring section. Review these logs periodically to verify that agent activity matches your expectations.

​Protocol authentication

​Tool definitions

​1. store_asset

​2. check_status

​3. check_in

​Implementation example

​Security best practices

Protocol authentication

Tool definitions

1. store_asset

2. check_status

3. check_in

Implementation example

Security best practices