feat(mcp): add mcp.call.before plugin hook for per-call MCP request headers#28319

Open

egze wants to merge 13 commits into

anomalyco:devfrom

egze:feature/mcp-call-before-hook

Commits on Jun 1, 2026

feat(plugin): declare mcp.call.before hook type

Aleksandr Lossenko
authored and
egze
committed
feat(mcp): add McpCallContext AsyncLocalStorage

authored and
egze
committed
feat(mcp): attach server/tool metadata to MCP.tools() output

authored and
egze
committed
refactor(mcp): inline test-only export and widen tools() return type

authored and
egze
committed
feat(mcp): per-call fetch wrapper reads McpCallContext headers

authored and
egze
committed
fix(mcp): lowercase all header keys in fetch merge; use SDK FetchLike type

authored and
egze
committed
test(mcp): integration test that mcp.call.before headers reach fetch

authored and
egze
committed
docs: document mcp.call.before plugin hook

Aleksandr Lossenko
authored and
egze
committed
chore: generate

Aleksandr Lossenko
authored and
egze
committed
test(mcp): cover plugin-throws path, transport fetch wiring, header preservation; cleanup

authored and
egze
committed
feat(session): fire mcp.call.before and seed McpCallContext in resolve()

authored and
egze
committed
docs: add mcp.call.before to user-facing plugin and MCP docs

authored and
egze
committed
docs(mcp-servers): add Per-call headers subsection with plugin snippet

Aleksandr Lossenko
authored and
egze
committed