[sacOO7]

Summary

Rewrites the README for the 2.0 ably-pubsub-server gem to match the other Ably Pub/Sub 2.0
READMEs: an overview modelled on the Go README, one-line requirements and the migration table after
the quick start. Only README.md changes.

What changed

• Overview: a one-sentence intro, the server-only note and a table with the two factory methods. The gem badge points at ably-pubsub-server.
• Requirements: Ruby 2.7 or later, plus libcurl with the Debian install command.
• Installation: bundle add ably-pubsub-server.
• Quick start: realtime and HTTP samples, a two-sentence server-token note that links to the docs page on server clients and token authentication, and a token request served from a Sinatra endpoint at /ably-auth, which device SDKs use as their authUrl.
• Migrating from 1.x: a top-level section after Quick start, with a 1.x to 2.0 table covering the ably and ably-rest gems.
• Common configuration: Endpoint, with the port and TLS rules, and Logging.
• Platform notes and Known limitations: the EventMachine requirements, and no LiveObjects, token revocation, delta compression or push targets.
• API key: server samples read it from the ABLY_API_KEY environment variable.
• Links: repository files use absolute GitHub URLs.

How it was validated

• Every claim was checked against the source on main: factory methods, option names, auth.create_token_request, the gemspecs and the CI matrix.
• All Ruby samples pass ruby -c.
• The /ably-auth endpoint sample runs under Sinatra against the main sources. With a dummy key, it returns a token request with Content-Type: application/json.
• The UPDATING.md anchors exist at main. External links return 200.
• An independent review checked facts, samples, links and markdown rendering.

Follow-ups

• The #server-token-auth anchor on the token authentication docs page is not published yet; the link opens the top of the page until it is.
• The ably/ably-ruby-rest README still recommends the 1.x ably gem.

Risk Assessment