Claude Report — 2026-05-19

🚀 Anthropic Official

Anthropic acquires Stainless — May 18

Stainless has generated every official Anthropic SDK (TypeScript, Python, Go, Java, Kotlin), CLI, and MCP server since the API launched, and is used by hundreds of companies including OpenAI, Google, and Cloudflare. Reported price: $300M+; existing Stainless customers retain full rights to SDKs already generated, but the technology goes Anthropic-exclusive going forward. Founder Alex Rattray cites shared focus on developer experience; Anthropic Head of Platform Engineering frames it as critical infrastructure for agent connectivity.

API: MCP Tunnels — Research Preview — May 19

Opens an outbound-only encrypted connection from an agent to a private-network MCP server — no inbound firewall rules, no public endpoint. Available in Managed Agents and the Messages API; managed via workspace settings in the Claude Console. Ships with explicit "as-is" language and a third-party transport dependency.

API: Managed Agents — self-hosted sandboxes, live MCP updates, large-output spilling — May 19

Three additions in one drop: (1) self-hosted sandboxes let teams run tool execution on their own infrastructure instead of Anthropic's (agent orchestration loop stays on Anthropic); (2) live MCP config updates allow modifying an agent's MCP server and tool configuration without ending the active session; (3) large-output spilling automatically writes agent_toolset or MCP tool outputs exceeding 100K tokens to a sandbox file and gives the model a truncated preview with the file path to read from.

API: Web search returns richer SEC filing data — May 18

The web search tool now surfaces richer SEC filing content, making it easier to ground financial research agents, earnings analysis, and due-diligence workflows in primary sources with inline citations.

Claude Code v2.1.144 — May 19

Adds /resume for background sessions (sessions started via claude --bg or agent view now resumable) with elapsed duration in completion notifications; /plugin browse/discover panes now show last-updated date per plugin; /model changes now scope to the current session only — press d to set as default for new sessions; "extra usage" renamed to "usage credits" (/extra-usage still works). Fixes: startup hanging up to 75s when api.anthropic.com is unreachable (now 15s cap), terminal rendering corruption in very long sessions, macOS background sessions crashing under Full Disk Access, and MCP servers with paginated tools/list only returning the first page.

🔌 Claude Code Plugins

None of the top 10 updated in window.

Unchanged in window: frontend-design, superpowers, context7, code-review, code-simplifier, github, skill-creator, playwright, feature-dev, claude-md-management

🛠️ Skills

No updates confirmed for top 5 in window.

Unchanged in window: obsidian-second-brain (last: May 15, prior window), frontend-slides (May 14), hue (Apr 17), gpt-image2-ppt-skills (unverified date), Agentic-SEO-Skill (unverified date)

🤖 Agents & Subagents

No updates confirmed for top 5 in window.

Unchanged in window: affaan-m/everything-claude-code (last release Apr 5), rohitg00/awesome-claude-code-toolkit (no release in window). Topics claude-agent and claude-subagent — no new versioned releases confirmed in window.

🔗 MCPs & Integrations

github-mcp-server v1.0.5 — May 18

Adds IFC label support to list_issues, get_file_contents, search_issues, issue_read, and search_repositories; implements missing pagination for get_reviews; adds an optional rationale param to update_issue_type; improves code search results with text match snippets; introduces a tool to list repo collaborators; adds discussion comment write operations; upgrades go-github to v0.87. Seven contributors, two first-timers.

Unchanged in window: modelcontextprotocol/servers (last release Jan 2026), steipete/claude-code-mcp (last push May 15, one day prior), ChromeDevTools/chrome-devtools-mcp (not checked this cycle), modelcontextprotocol/python-sdk (last confirmed release 2025)

💡 Community — Workflows & Ideas

No relevant community news today.

📰 Quick Mentions

• Three new Carta equity-management plugins — carta-cap-table (May 16), carta-crm and carta-investors (May 19) added to the official marketplace; together they cover cap-table access, CRM, and investor-relations data as agent tools.
• New plugin: convex-backend — Added May 18; gives agents real-time query and mutation access to Convex backend databases.
• New plugin: save-to-spotify — Added May 18; allows agents to add tracks to a user's Spotify library.
• Plugin SHA bumps now run nightly instead of weekly — The official marketplace CI job that refreshes plugin SHA pins to upstream HEAD was switched to a nightly cadence on May 18.
• Code with Claude London — Opened May 19, runs through May 21; follow-up developer event to the San Francisco conference held May 6.