# Runtime Capabilities

URL: /bengal/docs/ship/configuration/capabilities/
Section: configuration
Tags: persona-operator, persona-site-builder

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Runtime Capabilities Runtime capabilities are opt-in, self-hosted vendor features — Mermaid diagrams, KaTeX math, Iconify icon packs, and third-party packages you install. Bengal provisions vendor files at build time and emits them only on pages that actually use the feature. There are zero runtime CDN requests by default. Capabilities must be explicitly enabled in config and vendor files must exist under assets/vendor/ before templates emit script or link tags. Enable and disable [capabilities] mermaid = true katex = true iconify = true # implied automatically when mermaid content is present Each key is an allow-list entry. Disabled capabilities never download vendors and never appear in output, even if your theme supports them. Use the CLI to inspect the registry: bengal capability list bengal capability info mermaid bengal capability validate Per-page emission (content detection) Site-wide enablement does not mean site-wide asset tags. Bengal detects capability usage per page — a ```mermaid fence, inline $...$ math, or matching HTML markers — and emits vendor assets only where needed. The home page without diagrams ships zero Mermaid vendor tags even when [capabilities].mermaid = true. Supply-chain overrides Override how individual capabilities are provisioned: [capabilities.sources.mermaid] source = "local" path = "vendor/mermaid.min.js" [capabilities.sources.katex] pin = "0.16.11" require_sri = true Key Purpose source cdn (default) or local path / local_path Required when source = "local" pin Override the default version pin sri Expected integrity hash for verification require_sri Fail the build on SRI mismatch (default true) Templates emit integrity and crossorigin="anonymous" on vendor tags when hashes are known. CDN provisioning policy Restrict which CDN origins Bengal may download from during build-time provisioning: [capabilities.policy] allowed_cdn_origins = ["cdn.jsdelivr.net", "unpkg.com"] Or deny all CDN downloads (airgapped / strict CSP deployments): [capabilities.policy] cdn_mode = "deny" When cdn_mode = "deny", use source = "local" under [capabilities.sources.<name>] for every enabled capability. Versioned documentation builds Tagged version worktrees inherit the orchestrating build's [capabilities] config. Build-environment decisions (which vendors to provision) apply across all version builds — historical tags do not need to have shipped capability config themselves. Third-party capabilities Packages register via the bengal.capabilities entry point. See Plugin Development for author guidance and the examples/capability-demo/ reference package for an end-to-end sample. Related Capabilities vs theme features Authoring a capability package

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Metadata:
- Author: lbliii
- Word Count: 366
- Reading Time: 2 minutes