A developer known as "tiki" has open-sourced substack-digest, a lightweight tool that uses the Anthropic API to solve a problem many heavy readers will recognize: subscribing to dozens of newsletters and reading none of them. Faced with 169 Substack subscriptions and what they described as "information bankruptcy," tiki built an automated daily digest in roughly one hour using <a href="/news/2026-03-15-wikigen-go-cli-github-wiki-claude-code">Claude Code's browser automation capabilities</a>. The system scrapes subscription URLs from Substack's Library page, polls each publication's RSS feed (accessible by appending /feed to any Substack URL), uses Claude to generate a concise summary of each new post published in the past 24 hours, and delivers the compiled digest via a GitHub Actions workflow that fires at 7am each morning. The project is at github.com/tikiverse/substack-digest.
The Python implementation is configured through GitHub Secrets for the Anthropic API key and SMTP credentials. Optional environment variables control the lookback window, per-post character limits, and model selection. Tiki routed the automation through a dedicated Gmail service account rather than a primary inbox — a least-privilege security practice more common in enterprise deployments than personal productivity scripts. A companion script, sync_feeds.py, uses Playwright to re-scrape Substack subscriptions when the feeds.json file goes stale, handling the subscription list maintenance problem that most commercial tools sidestep entirely.
Commercial newsletter digest tools occupy a wide price range. Free options like Summaletter use a forwarding-address model; mid-market products like Summate and Readless sit in the middle; AI email clients like Meco ($9.99/month) and Superhuman (reported at $30-40/month) sit at the top. Mailbrew, which pioneered the daily digest email format, was acquired by Readwise in 2023 and shut down shortly after — a consolidation move that left a visible gap the current crop of tools is competing to fill. Shortwave has taken the most ambitious path, launching an agentic automation beta that connects inbox events to Slack, Notion, and Asana via MCP.
The DIY approach offers things subscriptions cannot: zero marginal cost beyond API usage, full data transparency, and the freedom to modify anything. Tiki's use of Substack's public RSS endpoints — an underexploited interface that commercial tools haven't built dedicated discovery automation around — also highlights how developers are reaching for the Anthropic API to handle triage work, not to orchestrate complex multi-step workflows. One day into running the system, tiki reported surfacing a valuable article from a long-forgotten subscription. It's a small return, but it's the return the whole thing was built for.