Phase 2: Credential supply for official MCP providers (google-ads-official, ga4-official)

[hyoshi]

Summary

Phase 1 made the official MCP providers register and connect correctly (the ~/.claude.json / claude mcp registration root-cause family is fixed). However, an installed official provider is currently unusable because mureo never supplies it any credentials. This issue tracks the Phase 2 work that catalog.py notes already defer ("OAuth Proxy and ADC modes are deferred to Phase 2").

Scope: google-ads-official and ga4-official (the pipx-based official providers). meta-ads-official is hosted-OAuth and out of scope.

Problem detail

1. No env injection. The install path writes only command/args into ~/.claude.json. ProviderSpec.required_env is declared in catalog.py but nothing reads it to populate the MCP server's env block. The official server therefore starts with no credentials.
2. No credential acquisition path. The configure wizard's official-provider branch has no Developer Token / OAuth step — only meta-ads-official (hosted OAuth) is special-cased in auth_wizards.js. ~/.mureo/credentials.json (the mureo auth setup output) is never wired into the official provider's environment.
3. Coexistence regression. Installing an official provider sets MUREO_DISABLE_<PLATFORM>=1 on the mureo native block, disabling mureo's own tools for that platform. Net result today: official has no creds AND native is disabled → the user is left with both unusable.
4. Auth-mode mismatch to resolve. catalog.py assumes Google Ads Client-Library mode (GOOGLE_ADS_DEVELOPER_TOKEN, GOOGLE_ADS_CLIENT_ID, GOOGLE_ADS_CLIENT_SECRET, GOOGLE_ADS_REFRESH_TOKEN). The upstream googleads/google-ads-mcp README documents ADC mode (GOOGLE_APPLICATION_CREDENTIALS + GOOGLE_PROJECT_ID + GOOGLE_ADS_DEVELOPER_TOKEN). ga4-official needs a service-account JSON (GOOGLE_APPLICATION_CREDENTIALS + GOOGLE_PROJECT_ID). The supported auth mode(s) must be verified against the real upstream packages before implementing.

Decisions required (product/architecture)

• A. Credential delivery: inject ~/.mureo/credentials.json GOOGLE_ADS_* values into the official MCP env block at install time?
  • Security tradeoff: this writes secrets into ~/.claude.json. Need a decision on acceptability / masking / file perms, and whether values are injected by reference vs. literal.
• B. Credential acquisition: add a Developer Token + OAuth (or ADC service-account) step to the wizard for google-ads-official / ga4-official when credentials are missing, or require mureo auth setup as a prerequisite.
• C. Coexistence gating: do NOT set MUREO_DISABLE_<PLATFORM>=1 until the official provider is actually credentialed, so the user is never left with zero working tools.
• D. Auth-mode alignment: resolve Client-Library vs ADC for google-ads-mcp, align catalog.py required_env + notes + docs accordingly.

Acceptance criteria

• Installing google-ads-official / ga4-official via the configure wizard results in a server that is ✓ Connected and can execute an authenticated call (not just connect).
• If credentials are missing, the wizard guides the user to provide them (or clearly states the prerequisite) rather than silently producing a dead server.
• mureo native tools for a platform are never disabled unless the official replacement is verified working (decision C).
• catalog.py required_env, notes, and user docs match the auth mode actually implemented.
• Tests cover: env injection from credentials.json, missing-credential UX, coexistence gating; validated against the real artifact (claude mcp get + an authenticated provider call), not only green unit tests.

References

• Relevant code: mureo/providers/catalog.py (required_env + Phase-2 notes), mureo/providers/config_writer.py (provider registration), mureo/providers/mureo_env.py (MUREO_DISABLE_*), mureo/_data/web/auth_wizards.js (wizard official branch), mureo/web/setup_actions.py, mureo/web/status_collector.py.
• Phase 1 / related: feat: Browser-based config UI for non-engineer onboarding #88 (browser-based config UI). Phase 1 fixed the settings.json → ~/.claude.json MCP registration root cause; this issue is the deferred credentialing follow-up.