fix(claude): isolate capability probe from user MCP servers

[jbbottoms]

What Changed

• Claude capability probe (probeClaudeCapabilities) now passes empty mcpServers with strictMcpConfig: true, so the ~5 minute refresh loop does not boot user/project/local MCP servers.
• Probe env sets ENABLE_CLAUDEAI_MCP_SERVERS=false to block claude.ai connectors on the same path.
• Probe runs from ~/.t3/claude-capability-probe instead of inheriting the server process cwd (often $HOME).
• Added unit coverage for the probe option builder.

Why

Fixes #3909. The capability probe loaded settingSources: ["user","project","local"] without MCP isolation. Every refresh spawned configured stdio MCP servers from the server cwd. A wedged MCP (e.g. serena scanning $HOME) accumulated orphans and froze the host (~46 GiB RSS in the report).

Real chat sessions are unchanged -- only the lightweight init probe is isolated.

Validation

• pnpm exec vp test run src/provider/Layers/ClaudeCapabilitiesProbe.test.ts -> 2/2 passed

Notes

• CONTRIBUTING: small reliability fix; no feature scope.
• Authorship: Jaret Bottoms 25535214+jbbottoms@users.noreply.github.com

Note

Isolate probeClaudeCapabilities from user MCP server configuration

The capability probe was previously susceptible to user-configured MCP servers interfering with results. buildClaudeCapabilitiesProbeQueryOptions now constructs probe options with mcpServers={}, strictMcpConfig=true, and ENABLE_CLAUDEAI_MCP_SERVERS=false, while retaining user/project/local setting sources. Tests verify that probe invocations match these strict no-MCP expectations.

^{Macroscope summarized 33f8b50.}

Summary by CodeRabbit

• Bug Fixes

  • Improved Claude capability detection reliability by isolating probes from user and project MCP configurations.
  • Prevented capability checks from persisting sessions or invoking unintended tools.
  • Ensured probe data uses a stable working directory and avoids repeated side effects.

• Tests

  • Added coverage for Claude probe configuration, environment handling, and working-directory resolution.

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Note

Medium Risk
Changes only the periodic Claude init probe, but it alters how the Agent SDK is invoked (MCP isolation); misconfiguration could break provider verification without affecting normal sessions.

Overview
Fixes capability health checks repeatedly spawning user/project/local MCP servers (and claude.ai connectors), which could wedge the host during the ~5 minute refresh loop.

Introduces buildClaudeCapabilitiesProbeQueryOptions so probeClaudeCapabilities uses a single, explicit SDK options shape: mcpServers: {} with strictMcpConfig: true, allowedTools: [], unchanged settingSources (user, project, local) for slash-command discovery, and probe env ENABLE_CLAUDEAI_MCP_SERVERS=false even when the caller env has it enabled. Real chat sessions are untouched—only this lightweight init probe.

Adds ClaudeCapabilitiesProbe.test.ts for the builder assertions and a fake-Claude integration test that verifies strict no-MCP CLI flags while account/slash-command data still resolves.

^{Reviewed by Cursor Bugbot for commit 33f8b50. Bugbot is set up for automated code reviews on this repo. Configure here.}

[coderabbitai]

📝 Walkthrough

Walkthrough

Claude capability probes now use exported configuration helpers that disable user MCP loading, prevent session persistence, and apply a stable working directory under ~/.t3. Tests cover query isolation and probe CWD resolution.

Changes

Claude probe isolation

Layer / File(s)	Summary
Probe configuration helpers and tests apps/server/src/provider/Layers/ClaudeProvider.ts, apps/server/src/provider/Layers/ClaudeCapabilitiesProbe.test.ts	Adds settings-source configuration, stable CWD resolution, isolated query options, and tests for MCP suppression, environment wiring, and path resolution.
Stable probe-directory execution apps/server/src/provider/Layers/ClaudeProvider.ts	Creates the probe directory and passes its CWD and generated options into probeClaudeCapabilities.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Suggested reviewers: juliusmarminge, marve10s

Sequence Diagram(s)

sequenceDiagram
  participant CapabilityProbe
  participant ProbeDirectory
  participant ClaudeQuery
  CapabilityProbe->>ProbeDirectory: create ~/.t3/claude-capability-probe
  CapabilityProbe->>ClaudeQuery: provide isolated MCP options and probe cwd
  ClaudeQuery-->>CapabilityProbe: execute capability probe

Loading

Poem

I’m a rabbit with a tidy new trail,
No MCP servers leap through the veil.
A quiet CWD, a cautious query,
Keeps each probe small, calm, and cheery.
Hop hop—safe checks prevail!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes satisfy #3909 by disabling MCP loading for probes and using a dedicated probe cwd.
Out of Scope Changes check	✅ Passed	The added helper extraction, environment flag, and tests all support the linked probe-isolation fix.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Title check	✅ Passed	The title is concise and accurately summarizes the main change: isolating the Claude capability probe from user MCP servers.
Description check	✅ Passed	The description covers What Changed, Why, and Validation, and is mostly complete despite omitting the checklist section.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[jbbottoms]

@coderabbitai review

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[macroscopeapp]

Approvability

Verdict: Approved

This is a well-scoped bug fix that isolates the Claude capability probe from user-configured MCP servers. The change extracts existing options into a testable helper and adds isolation flags to prevent MCP servers from interfering with health checks. Comprehensive tests validate the new behavior.

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@apps/server/src/provider/Layers/ClaudeProvider.ts`:
- Around line 647-650: Remove the `.pipe(Effect.orDie)` from the
`Effect.tryPromise` handling `NodeFS.promises.mkdir` in the probe flow, allowing
directory creation failures to remain in the expected error channel and be
mapped to `undefined` capabilities by the existing downstream handling.
- Line 646: Update the call to resolveClaudeCapabilitiesProbeCwd in the Claude
provider probe flow to pass the configured HOME from claudeEnvironment, ensuring
account-specific or isolated environments use their intended probe directory
instead of the default system home.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: de151275-5b58-47e2-ae0c-690bb9ac5625

📥 Commits

Reviewing files that changed from the base of the PR and between ecb35f7 and 1baa467.

📒 Files selected for processing (2)

• apps/server/src/provider/Layers/ClaudeCapabilitiesProbe.test.ts
• apps/server/src/provider/Layers/ClaudeProvider.ts

Dismissing prior approval to re-evaluate fe6c6b4

[juliusmarminge]

Probe runs from ~/.t3/claude-capability-probe instead of inheriting the server process cwd (often $HOME).

doesn't this mean we miss skills/commands?

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

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Dismissing prior approval to re-evaluate 33f8b50