Skills system backend work for ToolHive Studio

[samuv]

Summary

Backend and CLI work in toolhive supporting the skills feature in ToolHive Studio (stacklok/toolhive-studio#1981). All changes landed between Apr 6 – Apr 28, 2026.

Multi-client installation

• Support multi-client and all-clients skill installation #4732 — Support multi-client and all-clients skill installation
• Add supports_skills to GET /api/v1beta/discovery/clients response #4699 — Add supports_skills to discovery/clients response

Replaced single-client install with --clients array and all shorthand. Exposed supports_skills in the discovery API for the Studio UI to filter clients.

Client expansion

• Add Cursor as a skill-supporting client #4762 — Cursor
• Add VS Code and VS Code Insiders as skill-supporting clients #4773 — VS Code + VS Code Insiders
• Add Goose, Gemini CLI, and Amp as skill-supporting clients #4799 — Goose, Gemini CLI, Amp
• Add Kiro as a skill-supporting client #4803 — Kiro
• Add Cline, Roo Code, Windsurf, Mistral Vibe, Trae, and Antigravity as skill-supporting clients #4804 — Cline, Roo Code, Windsurf, Mistral Vibe, Trae, Antigravity
• Add Kimi Code CLI as a supported MCP client #4788 — Kimi Code CLI (MCP + skills)
• Add Factory.ai as a supported MCP client #4795 — Factory.ai (MCP + skills)

Build management

• Add thv skill builds command to list locally-built OCI artifacts #4499 — thv skill builds list command
• Add thv skill builds command to list and remove locally-built OCI skill artifacts #4674 — Add thv skill builds remove and blob GC
• Mark local skill builds with an OCI descriptor annotation #5000 — Mark local skill builds with an OCI descriptor annotation

Content preview API

• Add GetContent API for on-the-fly SKILL.md retrieval from OCI and git sources #4810 — GET /api/v1beta/skills/content?ref= for SKILL.md retrieval without installing
• Classify OCI pull errors and fall back to git for skills content API #5014 — Classify OCI pull errors and fall back to git for skills content API

OpenAPI spec

• Add OpenAPI annotations to v0.1 skills registry endpoints #4800 — Add annotations to v0.1 skills endpoints
• Address review findings from v0.1 skills OpenAPI PR #4802 — Review fixes (limit clamping, schema descriptions)
• Document 502 Bad Gateway failure for installSkill in OpenAPI spec #4960 — Document 502 Bad Gateway failure for installSkill

Refactoring

• Split skillsvc into per-concern files #4947 — Split skillsvc into per-concern files

Bug fixes

• Fix skill install failure when multiple clients share the same directory #4796 — Fix install when multiple clients share the same directory
• Fix skill install for qualified namespace/name references and missing parent directory #4841 — Fix install for namespace/name refs + missing parent dir
• Remove empty parent directories on skill uninstall #4895 — Clean up empty parent dirs on uninstall
• Only install skills for clients detected on the system #4899 — Only install skills for clients detected on the system
• Return 502 Bad Gateway when OCI skill pull fails #4956 — Return 502 Bad Gateway when OCI skill pull fails
• Classify packager errors as 400 in skill build handler #5076 — Classify packager errors as 400 in skill build handler
• Apply request version to tag-less skill OCI install ref #5078 — Apply request version to tag-less skill OCI install ref