Varnish Cache
Varnish Cache is a high-performance HTTP accelerator and reverse proxy designed for content-heavy dynamic websites and APIs. It sits in front of web servers and caches HTTP responses to serve repeated requests without hitting the backend, dramatically reducing load and latency. Varnish is configured via VCL (Varnish Configuration Language), a domain-specific language for request/response policy, and managed through a CLI interface (varnishadm) and a set of command-line tools for logging, statistics, and monitoring.
More than an index entry, but the surface is still mostly links rather than artifacts — the cohort most likely to move a full band from modest, well-targeted work.
API Evangelist profiles Varnish Cache the way a machine reads it — 32 machine-readable artifacts across 3 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Varnish Cache scores 25.7/100 (emerging), with a separate agent-readiness read of 7/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Varnish Cache
Each block below is one kind of artifact we hold for Varnish Cache. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 3
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Varnish Cache CLI API
The Varnish Cache CLI management interface provides programmatic control over a running Varnish instance. It is accessible via varnishadm or TCP socket and supports configuratio...
Varnish Logging Tools
Varnish ships with a suite of log-analysis tools that read from the Varnish Shared Log (VSL). Tools include varnishlog (raw log streaming), varnishncsa (NCSA/Apache log format),...
Varnish Modules (VMODs)
VMODs are extensions written for Varnish Cache that extend VCL capabilities. Bundled modules include blob (binary data handling), cookie (HTTP cookie parsing), directors (load b...
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Varnish Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Varnish Finops
FINOPSFeatures 10
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
Notable capabilities this provider offers.
HTTP Caching
Caches HTTP responses to reduce backend load and improve response times for repeated requests.
VCL Configuration Language
Domain-specific language for defining request/response handling policies with full programmability.
CLI Management Interface
TCP-based management interface for runtime configuration, VCL deployment, and cache control.
Backend Health Probes
Configurable health checks for backends with automatic failover to healthy backends.
Cache Invalidation (Bans)
Flexible cache invalidation via ban expressions matching any request/response attribute.
JSON Output
CLI commands support -j flag for structured JSON output, enabling programmatic management.
VMOD Extension System
Loadable modules (VMODs) extend VCL with cookie parsing, load balancing, digest, auth, and more.
HTTP/2 Support
Native HTTP/2 support via the h2 VMOD for modern protocol acceleration.
Shared Memory Log (VSL)
High-speed shared memory logging with rich request/response attributes for analysis tools.
Multi-threaded Architecture
Worker thread pool for high-throughput concurrent request handling with configurable threading.
Scroll within the panel for all 10 ·
Security Posture 1
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Use Cases 7
What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.
What developers build with this provider.
API Gateway Caching
Cache REST API responses at the edge to reduce database and application server load.
CDN Origin Shield
Act as origin shield between CDN edge nodes and web/application servers.
Static Asset Acceleration
Cache and serve static assets (images, JS, CSS) with long TTLs.
A/B Testing
Use VCL to route traffic fractions to different backends for controlled experiments.
DDoS Mitigation
Absorb traffic spikes and rate-limit abusive clients via VCL policies.
Authentication Offloading
Offload token validation and session checks to VCL logic at the cache layer.
Request Routing
Route requests to different backend pools based on URL patterns, headers, or cookies.
Scroll within the panel for all 7 ·
Integrations 8
Pre-built integrations with other platforms tell you where this provider already fits in a stack.
Pre-built integrations with other platforms and tools.
Nginx
Common deployment pairing with Nginx as backend web server behind Varnish.
Apache HTTP Server
Classic deployment with Apache as origin server behind Varnish Cache.
Kubernetes
Deployable as a sidecar or DaemonSet in Kubernetes clusters for service-level caching.
Prometheus
Varnish statistics exportable via varnish_exporter for Prometheus scraping.
Grafana
Community dashboards available for Varnish Cache statistics via Prometheus/Grafana.
Drupal
Deep integration with Drupal Cache Tags for efficient purging of cached pages.
WordPress
VCL configurations and plugins available for WordPress caching integration.
Fastly
Fastly CDN is built on Varnish Cache; Fastly VCL is a fork of Varnish VCL.
Scroll within the panel for all 8 ·
Resources
Every other property we hold for Varnish Cache — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Documentation 1
Reference material describing how the API behaves
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 1
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Company 3
The organization behind the API
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