Posting to Reddit from an agent

Reddit writes fail for agents in ways that look like bugs but aren't. The naive approaches — a scripted HTTP client, or Playwright/Puppeteer launching its own browser — hit walls no amount of retry logic fixes. Understanding why saves a long debugging spiral.

The architecture, and why

rdtx attaches over CDP to a Chrome the human launched, and issues writes as same-origin fetch calls from inside the logged-in page. Three measured facts make that the right shape; references/browser-session.md has the evidence.

The automation flag is set at launch, not by attaching. Puppeteer and Playwright pass --enable-automation, setting navigator.webdriver = true. Start Chrome with only --remote-debugging-port and attach afterwards, and it stays false.

"Prove your humanity" is transient. It's a JS proof-of-work that self-resolves in seconds, not a block. rdtx polls through it. Concluding you've been blocked is the most common way to abandon a working setup.