affaan-m/ECC was the No. 1 repo on GitHub on September 21, 2026. Ranks 2 to 5: BuilderIO/agent-native, cloudflare/security-audit-skill, trycua/cua and anthropics/financial-services. It replaced cloudflare/security-audit-skill at No. 1 from September 20, 2026. 5 of 10 are new since September 20, 2026, led by BuilderIO/agent-native. The full ranked top 10 is below, each with a short note on why it is trending.
affaan-m/ECC is new at 1 on the GitHub board, with 264.1K stars on the live repo page. BuilderIO/agent-native is new at 2 with 5464 stars. cloudflare/security-audit-skill falls 1 to 3 after leading yesterday. Five of yesterday's 10 leave: addyosmani/agent-skills, coder/coder, docling-project/docling, cloudflare/quiche, asciimoo/hister. The board is an agent-tooling swap, not a language-runtime story.
Top trending repos on GitHub: September 21
affaan-m/ECC: JavaScript agent-runtime optimization system for Claude Code, Codex, OpenCode, and Cursor. TopAIRepos put stars at 262.9K on September 20; the GitHub page fetch on this run showed 264.1K. New at 1. Do not copy the repo tagline into other copy: it uses a banned word.
BuilderIO/agent-native: TypeScript framework for agent-native apps (actions, chat, MCP, CLI) at agent-native.com. GitHub fetch: 5464 stars. Created 2026-03-12. New at 2.
cloudflare/security-audit-skill: Coding-agent skill for multi-phase security audits with machine-readable findings. GitHub fetch: 18,420 stars. Falls 1 to 3.
trycua/cua: Open-source computer-use stack (drivers, sandboxes, benchmarks) at cua.ai. GitHub listing: 22,122 stars. Falls 2 to 4 after yesterday's 2.
anthropics/financial-services: Claude plugin marketplace for investment banking, equity research, private equity, and wealth workflows. Official docs at claude.com/docs/office-agents/fsi-plugins. New at 5.
paperless-ngx/paperless-ngx: Document management system that OCRs and archives scans. GitHub listing: 43,601 stars. New at 6.
anthropics/claude-code: Terminal coding agent. GitHub fetch: 147.3K stars. Falls 5 to 7 after sitting at 5 yesterday and 2 on September 19.
mihail911/modern-software-dev-assignments: Course assignment repo for modern software development. New at 8. No widely reported news trigger identified for September 21, 2026 beyond the GitHub ranking itself.
higgsfield-ai/higgsfield: Higgsfield AI open repo that sat at 7 yesterday. Falls 7 to 9. Still on the board after the agent-skill wipe.
Open-Dev-Society/OpenStock: Self-hosted stock dashboard on Finnhub data, AGPL. AIPMClub dated an OpenStock mention to a September 20 digest at about 16,100 stars. Falls 6 to 10.
The live ranked board beyond the public top 10 is available via the Trends MCP API. Get your free API key
What changed on GitHub since yesterday
- New: affaan-m/ECC (1), BuilderIO/agent-native (2), anthropics/financial-services (5), paperless-ngx/paperless-ngx (6), mihail911/modern-software-dev-assignments (8).
- Movers: none at 5-plus among overlapping names. Security-audit-skill 1 to 3. Claude-code 5 to 7. OpenStock 6 to 10.
- Dropped: addyosmani/agent-skills (3), coder/coder (4), docling-project/docling (8), cloudflare/quiche (9), asciimoo/hister (10).
What today's GitHub trends reveal
Five new names is a real turnover day after yesterday's security-audit-skill lead. ECC at 1 with 264.1K stars is a recurring agent-runtime fixture returning to the daily 10, not a brand-new repo. Agent-native at 2 (5464 stars) is the small, new-framework contrast sitting next to claude-code at 147.3K stars in 7th.
Anthropic occupies two rows (financial-services 5, claude-code 7). Cloudflare's security-audit-skill stays on the board at 3 after losing 1.
Track these trends in real time with Trends MCP
This ranked list came from the Trends MCP get_top_trends tool. The same API is built for analysts, developer-relations teams, and agents who need a dated board instead of a screenshot. Star counts above are from GitHub page fetches on this run. The matching data source page is GitHub Trending Repos API.
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