Claude Nextjs Skills

Claude Next.js Skills

Claude Next.js Skills is a POC bundle of automations aimed at seeing if creating skills quickly could improve the Next.js eval scores published by Vercel at https://nextjs.org/evals.

Baseline (before skills)

Model	Success Rate
Claude Haiku 4.5	32%
Claude Sonnet 4.5	32%

Skilled Runs (after skills)

Model	Success Rate	Expected Leaderboard Slot
Claude Haiku 4.5 "Skilled"	78% (39/50)	1
Claude Sonnet 4.5 "Skilled"	76% (38/50)	2

Result Snapshot

Claude Haiku 4.5:

📊 Results: ════════════════════════════════════════════════════════════════════════════════

Eval	Claude Code
000-app-router-migration-simple	✅✅✅ (204.8s)
001-server-component	✅✅✅ (94.4s)
002-client-component	✅✅✅ (94.7s)
003-cookies	✅✅✅ (136.7s)
004-search-params	✅✅✅ (219.1s)
005-react-use-api	✅✅✅ (138.0s)
006-server-metadata	✅✅✅ (91.4s)
007-client-metadata	✅✅❌ (86.0s)
008-generate-static-params	❌✅❌ (83.0s)
009-og-images	✅✅✅ (108.0s)
010-route-handlers	✅✅✅ (69.1s)
011-client-server-form	✅✅✅ (167.9s)
012-parallel-routes	✅✅✅ (157.7s)
013-pathname-server	❌❌❌ (70.8s)
014-server-routing	✅✅❌ (94.0s)
015-server-actions-exports	✅✅❌ (69.6s)
016-client-cookies	❌✅❌ (65.9s)
017-use-search-params	✅✅❌ (59.7s)
018-use-router	✅✅✅ (72.6s)
019-use-action-state	✅✅✅ (120.3s)
020-no-use-effect	✅✅❌ (92.0s)
021-avoid-fetch-in-effect	✅✅✅ (238.6s)
022-prefer-server-actions	✅✅✅ (312.2s)
023-avoid-getserversideprops	✅✅✅ (166.2s)
024-avoid-redundant-usestate	✅✅✅ (111.5s)
025-prefer-next-link	✅✅✅ (120.9s)
026-no-serial-await	❌✅✅ (153.3s)
027-prefer-next-image	✅✅✅ (98.7s)
028-prefer-next-font	✅✅✅ (90.5s)
029-use-cache-directive	✅✅✅ (212.0s)
030-app-router-migration-hard	✅✅✅ (453.7s)
031-ai-sdk-migration-simple	✅✅✅ (178.7s)
032-ai-sdk-model-specification-string	✅✅✅ (194.9s)
033-ai-sdk-v4-model-specification-function	✅✅✅ (166.7s)
034-ai-sdk-render-visual-info	❌❌❌ (659.4s)
035-ai-sdk-call-tools	✅✅✅ (338.5s)
036-ai-sdk-call-tools-multiple-steps	✅✅✅ (307.9s)
037-ai-sdk-embed-text	✅✅✅ (155.0s)
038-ai-sdk-mcp	✅✅✅ (260.5s)
039-parallel-routes	✅✅✅ (217.6s)
040-intercepting-routes	✅✅✅ (208.4s)
041-route-groups	✅✅✅ (139.1s)
042-loading-ui	✅✅✅ (123.9s)
043-error-boundaries	✅✅✅ (138.4s)
044-metadata-api	✅✅✅ (115.6s)
045-server-actions-form	✅✅❌ (88.8s)
046-streaming	✅✅✅ (129.9s)
047-middleware	✅✅✅ (78.2s)
048-draft-mode	✅✅✅ (207.6s)
049-revalidation	✅✅✅ (124.2s)
--------------------------------------------	--------------------------
Overall (B/L/T)	45/48/40 (90%, 96%, 80%)

Claude Sonnet 4.5:

📊 Results: ════════════════════════════════════════════════════════════════════════════════

Eval	Claude Code
000-app-router-migration-simple	✅✅✅ (164.1s)
001-server-component	✅✅✅ (88.8s)
002-client-component	✅✅✅ (109.4s)
003-cookies	✅✅✅ (138.6s)
004-search-params	✅✅✅ (223.4s)
005-react-use-api	✅✅✅ (132.7s)
006-server-metadata	✅✅✅ (90.8s)
007-client-metadata	✅✅❌ (81.1s)
008-generate-static-params	❌✅❌ (78.0s)
009-og-images	✅✅✅ (105.3s)
010-route-handlers	✅✅✅ (75.1s)
011-client-server-form	✅✅✅ (179.3s)
012-parallel-routes	✅✅✅ (153.3s)
013-pathname-server	❌❌❌ (78.2s)
014-server-routing	❌✅❌ (103.1s)
015-server-actions-exports	✅✅❌ (76.0s)
016-client-cookies	❌✅❌ (71.5s)
017-use-search-params	✅✅❌ (64.1s)
018-use-router	✅✅✅ (77.2s)
019-use-action-state	✅✅✅ (123.8s)
020-no-use-effect	✅✅❌ (94.5s)
021-avoid-fetch-in-effect	✅✅✅ (269.8s)
022-prefer-server-actions	✅✅✅ (242.4s)
023-avoid-getserversideprops	✅✅✅ (207.7s)
024-avoid-redundant-usestate	✅✅✅ (126.4s)
025-prefer-next-link	✅✅✅ (96.4s)
026-no-serial-await	✅✅✅ (220.4s)
027-prefer-next-image	✅✅✅ (103.4s)
028-prefer-next-font	✅✅✅ (81.4s)
029-use-cache-directive	✅✅✅ (208.8s)
030-app-router-migration-hard	✅✅✅ (397.9s)
031-ai-sdk-migration-simple	✅✅✅ (233.2s)
032-ai-sdk-model-specification-string	✅✅✅ (150.4s)
033-ai-sdk-v4-model-specification-function	✅✅✅ (118.6s)
034-ai-sdk-render-visual-info	✅✅❌ (567.8s)
035-ai-sdk-call-tools	✅✅✅ (209.6s)
036-ai-sdk-call-tools-multiple-steps	✅✅✅ (247.7s)
037-ai-sdk-embed-text	✅✅✅ (181.0s)
038-ai-sdk-mcp	❌❌❌
039-parallel-routes	✅✅✅ (162.7s)
040-intercepting-routes	✅✅✅ (201.2s)
041-route-groups	✅✅✅ (147.7s)
042-loading-ui	✅✅✅ (141.3s)
043-error-boundaries	✅✅✅ (228.7s)
044-metadata-api	✅✅✅ (110.0s)
045-server-actions-form	✅✅❌ (101.0s)
046-streaming	✅✅✅ (126.4s)
047-middleware	✅✅✅ (91.2s)
048-draft-mode	✅✅✅ (210.0s)
049-revalidation	❌✅✅ (195.9s)
--------------------------------------------	--------------------------
Overall (B/L/T)	44/48/39 (88%, 96%, 78%)

Outcomes

Does this translate into improved real world code or is Claude now just optimised to better pass evals? This would be a great area to explore.

Please try and let me know.