HiddenContent
Check a document for hidden text before your agent reads it. PDF, Office, RTF, HTML.
The current version, v0.4.6, was published to the official MCP registry on 2026-09-01. It is distributed as @hiddencontent/mcp on npm, filed under Documents & Spreadsheets by this index, and declares 3 environment variables. Removals and unreachable sources are measured across every server this index tracks, contract drift across the servers that answer in consecutive snapshots; the index's current counts put this record in context.
Using HiddenContent in Claude, Cursor, Gemini CLI, Cline, or Zed?
MCP tool contracts can change remotely with no version bump. The mcpindex gate pins each contract and HOLDs the call when it drifts-before your agent acts. Zero credentials. This is not the package install for this server itself (use Install this server for that).
Rewrites your MCP host config so each server launches behind the gate. Inspect first: curl -fsSL https://mcpindex.ai/install.sh | less
uv tool install mcpindex-gate && mcpindex-config-wireVerdict not yet evaluated for this tool. The semantic screen takes adversarial cases first; coverage rolls out as the corpus expands (15/150 labels to graduation). The deterministic conformance probe is built but has not yet run on the public corpus, so a recorded verdict here is REVIEW or UNVERIFIED, never a clearing ALLOW. Until a verdict is recorded, an agent should treat this tool as not-yet-cleared and fall back to its own checks. Method: the eval, four-state verdict, honest limits.
Own this server? Screen its description →
That verdict was true at screening time (snapshot 2026-09-02).
Contracts can change after screening, with no version bump. The gate pins HiddenContent’s tool contracts on first sight and holds any silent change before your agent acts - the check that keeps being true on Tuesday.
See your first HOLD in 2 minutes →
Related: how to trust an MCP server · screen before install · silent contract drift
HCS_API_TOKENAPI token for the HiddenContent service. Get one at https://hiddencontent.ai/start — the server refuses to start without it and says so.
HCS_URLBase URL of the service. Defaults to the hosted API; set it only when pointing at a self-hosted instance.
HCS_CAPABILITIESComma-separated list of what your agent can actually do. The only accepted values are `tool-use`, `network-egress` and `code-execution`. These turn on the checks for concealed text that instructs a model to call a tool, send data or run code — declaring more can raise severity and never lowers it, and declaring nothing leaves those checks inert. Defaults to `tool-use` in the bundle install.
HCS_API_TOKENAPI token for the HiddenContent service. Get one at https://hiddencontent.ai/start — the server refuses to start without it and says so.
HCS_URLBase URL of the service. Defaults to the hosted API; set it only when pointing at a self-hosted instance.
HCS_CAPABILITIESComma-separated list of what your agent can actually do. The only accepted values are `tool-use`, `network-egress` and `code-execution`. These turn on the checks for concealed text that instructs a model to call a tool, send data or run code — declaring more can raise severity and never lowers it, and declaring nothing leaves those checks inert. Defaults to `tool-use` in the bundle install.
Convert documents and web pages to clean Markdown: PDF, DOCX, XLSX, EPUB, scanned files, any URL.
Turn PDFs, scans and photos into a queryable database. Invoices, CVs, receipts, in bulk.
Read-only Mafdet AI account tools (models, balance, usage, subscription) and docs search.