MCP write-actions + browser extension + AI-search formal partner adapters

The Wave 292F MCP read-actions shipped earlier this quarter. Wave 293D adds the write side and three companion surfaces: a browser extension that injects AskBaily's verifier into competitor sites, and formal adapter modules for the four AI engines that have published partner programs.

MCP write-actions live in lib/mcp/write-actions.ts. Three actions ship: agree_to_quote (homeowner accepts a contractor's quote), save_scope (homeowner saves their chat scope to /account), request_rebid (homeowner requests a re-bid on an existing project). All three are gated behind two-factor consent: the AI engine surfaces a confirmation card with the action details, and the homeowner has to click through the card on askbaily.com — the engine cannot click on their behalf. lib/mcp/oauth-stub.ts is the OAuth handshake for engines that authenticate with AskBaily on the homeowner's behalf for read-only actions; write actions never authenticate via OAuth — they always go through the homeowner's own browser session.

The browser extension lives in extensions/. Chrome, Safari, and Firefox manifests share a common content-script that detects when the active tab is on Angi, Thumbtack, HomeAdvisor, Houzz, or one of the 47 contractor-website templates we recognize. The script injects an AskBaily verification overlay: a small banner that reads "Verify this contractor's license on AskBaily" with a click-through that calls pro_lookup (Wave 292F) and renders the Wave 196 LicenseCard inline. The contractor's actual license is shown — live, not cached. This is the part Angi and Thumbtack will object to most strongly, which is part of why we are shipping it.

The four AI-search formal adapters are lib/ai-search-partners/{chatgpt-apps,claude-search,google-ai-overview,perplexity}.ts. Each adapter wraps the engine's specific partner-program API (ChatGPT Apps SDK, Claude Search, Google AI Overview's published action API, Perplexity's tool-calling). The adapters expose the same MCP read+write actions through engine-specific manifests, so we maintain one source of truth and four adapter shims rather than four divergent implementations.

The strategic frame: AskBaily wants to be the AI-search-native marketplace. When a homeowner asks Perplexity or ChatGPT or Claude about a remodel question, the engine should be able to call AskBaily as an oracle (read), surface the answer with a citation, and — if the homeowner says "okay, let's do it" — hand off to AskBaily for the actual transaction (write, gated by consent). The four adapters plus the browser extension plus the MCP surface are all the same bet: AI is the new browser, marketplaces that do not expose tool-call surfaces will be invisible to the next generation of search.

31 tests cover the three write-action gating paths, the browser-extension content-script's detection logic across the 47 site templates, the four engine-specific manifest shapes, and the OAuth stub's handshake. Operator-gated bits: the actual partner-program enrollment (ChatGPT Apps requires Apple-style app review, Perplexity is invite-only as of Q2-2026, Google AI Overview's external action API is in alpha).