Claude Code: Software Development Skills

Repair a Claude Code session whose transcript JSONL has an orphan servertooluse / toolresult content block, causing every API call (including /compact and claude --resume) to fail with HTTP 400 "unexpected tooluseid found in advisortoolresult blocks: srvtoolu... Each ... block must have a corresponding servertooluse block before it". Use when: (1) a Claude Code session dies mid-advisor call with "socket connection was closed unexpectedly", (2) resume / compact returns the 400 above naming srvtoolu..., (3) /remote-control (or any system event) activated mid-stream while the assistant was emitting an advisor response. Covers diagnosis via grouping JSONL lines by shared message.id, surgical deletion of the orphan pair (both halves), and the line-number-drift gotcha that occurs when the file grows between inspection and edit.

Repair a Claude Code session whose transcript JSONL has assistant messages containing a whitespace-only text block (typically {"type":"text","text":" "}), causing every API call (including new prompts, /compact, and claude --resume) to fail with HTTP 400 "messages: text content blocks must contain non-whitespace text". Use when: (1) a session refuses to accept new input with that exact 400, (2) /compact fails with the same 400 (since compact replays the full history first — it does NOT bypass the validator), (3) claude --resume immediately exits with the same error. Covers diagnosis via JSON-walking the message.content array (NOT plain grep — the empty block is often nested), the distinction between message.content (sent to API → must fix) and toolUseResult (local metadata → harmless, leave alone), the underlying cause (extended-thinking turn serialization emits a synthetic single-space placeholder before the thinking block), and an idempotent fixer script that replaces " " with "." while preserving message shape.