Printing Press is a great project! At a philosophical level, Pomerado is meant to be more autonomous - it's a standalone harness that you can run, and it's meant to require as little review as possible after the first request. If there are questions about the site or intent, we have coding agents with application context answer those questions.
We find this integrates into automated software development workflows a lot better, and my Openclaw can basically create new MCPs for me with little supervision required.
In terms of mechanisms, Pomerado uses a mix of HTTP requests and generated Playwright code. Printing Press has a far greater emphasis on making HTTP requests to the site's backend. We've found for some sites this latter approach can create issues around triggering anti-bot and can fail for more complicated forms and writes, so we use Playwright for those instances.
Pomerado's approach to researching the website is also a bit different - we solely focus on exploring the website itself, while Printing Press has your agent explore the web for documentation, SDKs, etc. There's a tradeoff of prompt injection security vs convenience there. Because we try to emphasize autonomous builds we limit the agent to the website for security.
A big pain point for us with existing approaches was using them for cloud agents (e.g., my Openclaw on my VPS). Cloud starts running into a lot of issues around hosting, authentication, and anti-bot, which is why we started offering a free hosted version of the open source, where we handle cloud browsers, proxy rotation, credential storage, CAPTCHAs, etc.
We're planning to roll out support for CLIs down the line! And the PR for non-OpenAI models + codex exec is in the works :)