MCP Support

What's Changed

Related video manual about MCP setup - https://www.youtube.com/watch?v=PfcDh0JekIk

1. Notable changes since 4.91v

   • AI MCP server: added a Model Context Protocol endpoint so external AI clients (ChatGPT custom connectors, Claude, and other MCP hosts) can inspect a Live Helper Chat installation; the endpoint aimcp/mcp speaks Streamable HTTP through the official mcp/sdk PHP SDK and is a thin bridge that only authenticates the caller and forwards the request, while the protocol itself (handshake, protocol revisions, sessions, tools/list, tools/call, JSON-RPC framing, CORS) is handled by the SDK; a new "MCP Setup" screen (aimcp/key, linked from the Rest API page and protected by the new lhaimcp/use permission) stores the server name and the access token, shows the endpoint URL and the list of exposed tools read directly from the tool attributes so the page cannot drift from tools/list; the endpoint stays disabled until a token is generated and accepts it either as an Authorization: Bearer <token> header or as a ?token= parameter (a generated token uses random_bytes and comparisons use hash_equals), and allowed CORS origins plus an optional host allowlist for the SDK DNS rebinding protection can be configured through the ai_mcp_options chat configuration.
   • MCP tools and helpers: eight read-only tools are exposed - get_user_id_by_email, get_user_id_by_username, get_user_permissions, get_url_permissions, check_user_object_access, explain_chat_access, get_department_auto_assign_settings and explain_chat_auto_assign; LiveHelperChat\Mcp\Access resolves a back office URL into module/view and the permissions it requires with the same logic as the permission explorer (absolute URL, plain path, with/without index.php, with/without siteaccess) and evaluates permissions grouped so that checks in the same group are OR-ed and different groups are AND-ed; LiveHelperChat\Mcp\Rules diagnoses object level access for departments, users, chats and canned message replace variables, reporting only identifiers, booleans and generic placeholders (no names, e-mail addresses, chat nicks or message bodies) and can be extended by extensions with the new ai_mcp.object_access_rules event; LiveHelperChat\Mcp\AutoAssign is a read-only port of erLhcoreClassChatWorkflow::autoAssign() which replays the candidate and gate checks without any write or lock, so it can be run safely against a live installation to answer "would chat X be auto assigned?" or "why was operator Y not auto assigned to chat X?".
   • MCP sessions and dependencies: handshake sessions are stored in the new lh_mcp_session table instead of per-request or per-node state, so the endpoint also works on load balanced installations; sessions expire one hour after the last write (the SDK default), a failing query is reported as a missing session instead of turning the endpoint into a PHP error page, and expired sessions are purged by the regular chat cleanup cron so the table stays small; composer.json gained the mcp/sdk and symfony/finder dependencies, erLhcoreClassSystem::$QueryString is now a declared property, ezcUrl::parsePathElement() no longer warns when a path element is null, and the new table is created by the regular database update.
   • Audit log size protection: audit records larger than the MySQL max_allowed_packet no longer break the operation being logged - oversized audit messages are truncated to a safe size (16 MB minus a 1 MB reserve for the rest of the query) with UTF-8 safe truncation and a marker showing the original size, and a failing log write is reported through error_log() instead of propagating up, unless debug_output is enabled so developers still see the error.
   • Chat transfer to human: chat/transfertohuman now runs inside a database transaction, loads the chat with fetchAndLock() and locks the department before changing the state, re-validates the chat hash and status after the lock was acquired, and returns a JSON error instead of failing when the chat does not exist or was closed/transferred in the meantime; a missing chat is also handled safely when grouping canned message items, and incomplete canned message replace conditions (missing field, comparator or value) are skipped instead of raising warnings.
   • Assignment and SQL mode fixes: editing a department operator assignment returns "Assignment record was not found" instead of failing when the assignment record is missing; aggregate queries in the department operator lists (operators, operators group) and in collected survey results set sql_mode='' so installations with ONLY_FULL_GROUP_BY enabled can still list operators and survey results; the operator assignment priority field gained an explanation that it is only taken into account when the department enables assignment by operator priority, otherwise auto-assignment sorts by lowest workload / least recently accepted first.
   • Bot: the "Update message" bot command can now update the del_st (deleted status) field of a message, and the bot workflow translation/replace helper guards against a non-object chat.
   • Widget and operator profile: relative URIs in chat responses are treated as same site links, so they open inside the embedded chat instead of a new browser window; send button and in-progress icons received small padding and alignment fixes; new --lhc-message-spacing and --lhc-message-group-spacing CSS variables let a theme control the spacing between message bubbles and between message groups without overriding the whole stylesheet; the "job title in new row" theme option is now implemented with CSS classes (op-job-title-sep, operator-profile-content, op-photo) instead of duplicated template markup; the widget React app version was bumped.
   • Miscellaneous: updated install scripts, structure.json and db.dbml for the new lh_mcp_session table; bumped version to 4.92v.

2. Summary

   • This release focuses on AI tooling for administrators, plus reliability and compatibility fixes.
   • A Model Context Protocol endpoint lets AI clients read permission, access and auto-assignment information from an installation through eight read-only tools, protected by an access token and a dedicated lhaimcp/use permission.
   • MCP sessions live in the new lh_mcp_session table, making the endpoint safe for load balanced setups, with automatic expiry and cleanup.
   • Oversized audit records are truncated instead of breaking the logged operation, and a failing log write no longer interrupts the request flow.
   • Chat transfer to human, department assignments and SQL mode sensitive queries are hardened, and incomplete canned message replace conditions are handled safely.
   • Widget links, message spacing and operator profile job titles were polished.

execute doc/update_db/update_358.sql for update

• Treat relative ur is as same site in chat responses by @niels-heinemann in #2410
• Allow self-signed and unverified SSL certificates in Mailconv SMTP transport by @mysubcult in #2413

Full Changelog: 4.91v...4.92v