`mcp_cache_protocol`

Optional protocol for per-operation cache policy used by the MCP 2026-07-28 specification. An application may implement cache_policy/4 to choose TTL (milliseconds) and scope (public or private) for complete results of server/discover, list operations (tools/list, prompts/list, resources/list, resources/templates/list), and resources/read. Cache fields are never attached to input_required results or MRTR retries. When the predicate is not defined, or for an operation it does not cover, the server falls back to the options cache_ttl(0) and cache_scope(private).

| Availability: | logtalk_load(mcp_server(loader))

| Author: Paulo Moura | Version: 1:0:0 | Date: 2026-08-14

| Compilation flags: | static

| Dependencies: | (none)

| Remarks:

TTL: A non-negative integer number of milliseconds. 0 means the result must not be cached.
Scope: Either public (may be shared across clients) or private (client-specific).
Applicability: Only complete final results of discover, list, and resource-read operations receive cache fields. Tool calls, prompt gets that return input_required, and any MRTR continuation never include ttlMs / cacheScope.

| Inherited public predicates: | (none)

.. contents:: :local: :backlinks: top

Public predicates

.. index:: cache_policy/4 .. _mcp_cache_protocol/0::cache_policy/4:

cache_policy/4 ^^^^^^^^^^^^^^^^^^

Returns the cache policy for a given operation and request. Operation is one of discover, tools_list, prompts_list, resources_list, resources_templates_list, or resources_read. Request is the request-specific identifier or arguments (e.g. a resource URI for resources_read, or a free term for list/discover). TTL is a non-negative integer (milliseconds). Scope is public or private. Failure means the server should use its configured defaults.

| Compilation flags: | static

| Template: | cache_policy(Operation,Request,TTL,Scope) | Mode and number of proofs: | cache_policy(+atom,+term,-integer,-atom) - zero_or_one

Protected predicates

(none)

Private predicates

(none)

Operators

(none)