What's trending on GitHub today: September 4, 2026

fmtlib/fmt holds rank 1 on GitHub trending on September 4, 2026, at 25,305 stars, a C++ formatting library whose v12.2.0 line remains the only non-agent repo at the top. mattpocock/skills is new at 2 with 235,692 stars: a Claude Code plugin and skills.sh pack of 20-plus engineering skills. Versus the September 3 GitHub board, timesfm falls 2 to 9 and six yesterday names leave entirely. The GitHub Trending Repos API call used type GitHub and limit 10. Star counts below are from the public GitHub pages fetched on September 4.

fmtlib/fmt: Modern C++ formatting library. Holds 1. The GitHub page listed 25,305 stars on September 4. README work and release notes remain the why when news is thin.
mattpocock/skills: Agent-skill collection billed as Skills For Real Engineers. New at 2. The README offers a Claude Code plugin (claude plugins install mattpocock-skills) or npx skills@latest add mattpocock/skills, then /setup-matt-pocock-skills once per repo. 235,692 stars.
NousResearch/hermes-agent: Public agent repo tagged "The agent that grows with you." Climbs 7 to 3. GitHub listed 241,090 stars on September 4.
DietrichGebert/ponytail: Agent skill that "makes your AI agent think like the laziest senior dev in the room." Slips 3 to 4. 124,017 stars.
anthropics/skills: Anthropic's public Agent Skills repository. New at 5. 173,829 stars on the GitHub page fetched September 4.
affaan-m/ECC: Agent performance-optimization pack for Claude Code, Codex, OpenCode, and Cursor. New at 6. 247,552 stars, the highest star count on this board.
JuliusBrussee/caveman: Claude Code skill that "cuts 65% of tokens by talking like caveman." New at 7. 103,265 stars.
blader/humanizer: "Agent skill that removes signs of AI-generated writing from text." New at 8. 41,910 stars.
google-research/timesfm: TimesFM time-series foundation model from Google Research. Drops 2 to 9 (7 ranks). 30,825 stars.
averygan/reclip: Self-hosted media downloader with a web UI. New at 10. 8,607 stars.

The live ranked board beyond today's top 10 is available via the Trends MCP API. Get your free API key

What changed on GitHub since yesterday

New entrants: mattpocock/skills (2), anthropics/skills (5), affaan-m/ECC (6), JuliusBrussee/caveman (7), blader/humanizer (8), averygan/reclip (10).

Big movers: google-research/timesfm 2 to 9 (7 ranks down); NousResearch/hermes-agent 7 to 3 (4 ranks up).

Drop-offs: debpalash/VoiceStudio (4), sngyai/Sequoia-X (5), ChromeDevTools/chrome-devtools-mcp (6), superlinked/sie (8), pacifio/atlas (9), zyronon/TypeWords (10).

What today's GitHub repos reveal

Nine of 10 rows are agent tooling. fmt at 1 is the exception: a C++ library with 25,305 stars, not a skill pack. The rest of the board is installable agent behavior (skills, token-cutters, humanizers, a downloader).

Star counts and ranks do not match. ECC has 247,552 stars at rank 6; fmt has 25,305 at rank 1. The GitHub trending feed is a velocity board, not a lifetime-star sort.

timesfm's 7-rank drop is the day's research-model story. Google's forecasting repo is still in the top 10, just no longer the #2 narrative next to fmt.

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This list came from the Trends MCP get_top_trends tool with type GitHub and limit 10. The feed is for developer-ecosystem watchers who need a dated repo board.