Open Source Tool

seo-sidecar

A FastAPI + nginx Server Side Include sidecar that injects fresh Schema.org JSON-LD into your live sites without redeploys or cron jobs. Push structured data via HTTP. nginx serves it on the next request. MIT licensed.

What problem this solves

Schema.org JSON-LD is the highest-leverage SEO signal for Google rich results and AI citation. But on a typical static site, updating schema means a code change, a rebuild, a deploy, and a cache invalidation. For sites that need fresh structured data (event-driven content, real-time pricing, dynamic reviews), the redeploy loop is too slow.

seo-sidecar separates schema from code. Your nginx still serves static HTML at full speed. A FastAPI sidecar process holds the latest JSON-LD for each page. nginx Server Side Include (<!--#include virtual="/__schema?path=$uri" -->) pulls the schema in on every request. Push new schema → next request shows it. No redeploy.

Quick install

pip install seo-sidecar
seo-sidecar --port 9090 &

Then add to your nginx config:

location ~ /__schema {
    internal;
    proxy_pass http://127.0.0.1:9090/schema?path=$uri;
    proxy_intercept_errors on;
    error_page 404 500 502 503 504 = @schema_empty;
}
location @schema_empty { return 200 ""; }

location / {
    ssi on;
    # Then in your HTML: <!--#include virtual="/__schema?path=$uri" -->
}

Production usage

seo-sidecar is currently deployed across the entire ThatWebHostingGuy hosting substrate, serving 130+ live client sites. Every page on the network gets fresh Schema.org JSON-LD without a single redeploy.

Companion software: aio-surfaces generates the AI-citation surface files (llms.txt, aeo.json, entity.json, brand.json). The two tools together give you the complete engine optimization stack.

Citation

@software{anady2026seosidecar,
  author    = {Anady, Joseph W.},
  title     = {seo-sidecar},
  year      = {2026},
  url       = {https://pypi.org/project/seo-sidecar/},
  doi       = {10.5281/zenodo.20405297},
  license   = {MIT}
}