Debugging via MCP 0.7.0

0.7.0 — Watch list, long values and concurrency (preview)

Added

• Watch list: watch_add, watch_list, watch_remove. The agent follows expressions across stops: every answer that reports
  a stop (debug_wait, the steps, debug_status...) carries their values and whether each changed since the previous stop. At most
  10 entries; values are masked and shortened like those of vars. The list belongs to the agent's connection, lives in memory and is
  dropped when the agent lets go or disconnects; your Watch windows and your solution are not touched. These are Read tools: with Read
  set to Ask, reading the values at a stop asks nothing more. Needs the extension and the debugviamcp server of the same
  release (protocol 2.9); an older extension answers that it must be updated.
• eval with offset and length reads a long value in pages (up to 16384 characters per page, up to 2,000,000 per value). The
  value is read once, masked as a whole before it is cut (a secret split by a page boundary stays hidden) and the next pages come
  from that saved read. Not allowed together with allowSideEffects.
• A concurrency lab for testing (samples/ConcurrencyLab: a data race, a deadlock and a crash on a worker thread) with end-to-end
  scenarios in tests/e2e/concurrency-lab.cs.

Fixed

• A stop with several threads no longer fails as a whole when a frame has no source line. threads and the call stack answered
  E_FAIL and an empty snapshot; such frames are now listed without a file and line.
• eval, vars and drill-down on a thread that is blocked (waiting on a lock) answer eval_failed with a pointer to stack
  instead of an unclear error.
• The failure text of a paged read is masked and cut like every other value.
• debug_wait after a stop no longer asks again for consent just to read the watch values when Read is Ask.

Changed

• Reading a long value page by page and keeping a watch's prepared expression are faster; a connection that never added a watch no
  longer switches to Visual Studio's UI thread when it is released.

Debugging via MCP 0.6.0

0.6.0 — Settings on Visual Studio 2022 (preview)

Added

• An Options page for Visual Studio 2022 (17.14). Visual Studio 2022 does not show the extension's page in All Settings, so
  there was no way to change the permission tiers, the consent timeout, masking, the limits or the log level there. They are now in
  Tools → Options → Debugging via MCP → General and take effect when you press OK. In Visual Studio 2026 the settings stay in
  Tools → Options → All Settings → Debugging → Debugging via MCP, and the new page is not used there.

Fixed

• Visual Studio 2022: calls failed with busy for a dialog that was not there. The extension read Visual Studio's main window once
  and kept it; when that window was gone, every call that moves the program reported a dialog. The window is now taken from Visual
  Studio's own automation object and looked up again when it is no longer valid.
• exception_set with an empty name in names is refused before anything is written.
• When exception_set stopped halfway and putting back what it had written failed too, that change was forgotten. It now stays
  recorded, so exception_reset and the release when the agent disconnects can still undo it.

Changed

• The file attached to a GitHub Release carries the version: DebugViaMcp-<version>.vsix.

Debugging via MCP 0.5.0

0.5.0 — Exception settings (preview)

Added

• Exception settings: exception_list, exception_set, exception_reset. The agent can see which exceptions Visual Studio stops
  on when they are thrown (Debug → Windows → Exception Settings) and turn Break When Thrown on or off for named exceptions,
  so a debugging session stops where the exception is thrown instead of where it is caught. A call checks every name first and
  changes nothing when one is unknown (it offers close names). exception_reset puts back only what the agent changed, and Visual Studio puts it back by itself when the agent lets go or disconnects. These are
  Control tools: they ask like the other Control tools when you set that in Options. Needs the extension and the debugviamcp
  server of the same release (protocol 2.8); an older extension answers that it must be updated.

• Mask sensitive values (Tools → Options → All Settings → Debugging → Debugging via MCP, on by default): values that look
  like secrets (strings under names such as password or token, JWTs, Bearer tokens, PEM private keys, GitHub and AWS keys,
  Password= in connection strings, passwords in URLs) are replaced by [masked] before they reach the agent, in vars, eval,
  the arguments of a break, exception texts and output_read. The result carries masked: true. Turning it off asks you to confirm.
  A tracepoint that would print such a value is refused while it is on. A heuristic against accidental leaks, not a security boundary (see docs/security.md).

• vars opens several levels in one call. depth (1-4, default 1) puts the members of each object under children;
  expand names more paths to open in the same call (listed under expanded). Each object shows at most 20 members
  (childrenTruncated says there are more) and the answer stays small: what does not fit stays closed, and hasChildren
  still says it can be opened with path.

• debug_status with detail. Stopped at a break, detail: true also returns the top 10 frames of the Call Stack, the
  first 30 Locals and the exception (when the break is about one): where you are and what is going on in one call. A part
  Visual Studio cannot read is named under notes and the rest still comes.

• process_list lists your processes that debug_attach can attach to (pid and name), with an optional filter on part of
  the name, so the agent can pick a pid when several processes share a name.

• symbol_status says why a breakpoint may not bind: the debugger options that decide whether symbols load (Require source
  files to exactly match, Just My Code, Source Server, Suppress JIT optimization), the breakpoints that are not bound, and what
  can be behind it. It does not say which modules have symbols loaded; Visual Studio's automation does not offer the symbol path.

• bp_set with temporary. A one-shot breakpoint: it removes itself after the break it causes, and bp_list shows it
  (temporary: true) until then. A breakpoint that already existed is left as it is, and a tracepoint cannot be temporary.

• A dialog Visual Studio waits on is named, not waited for. When a modal dialog is open (for example the Hot Reload
  "changes not supported" question), debug_status returns its title under dialog, and every call that would move the
  program, build or change a value fails at once with busy and says which dialog to answer. Reads keep working. The check
  asks Windows about the main window only, so it costs no pause on Visual Studio's UI thread, and each held-back call is
  logged with its call id.

Changed

• debug_start builds first. A failed build comes back to the agent (read the diagnostics with errors_list) instead of
  leaving Visual Studio's "run the last successful build?" dialog open on screen.
• The Output panes are named by what they hold: Debugging via MCP Log (the technical log, formerly Debugging via MCP)
  and Debugging via MCP Audit (what the agent did, formerly Debugging via MCP Activity). The menu entry Show Activity
  is now Show Audit. The agent still cannot read either pane.

Debugging via MCP 0.4.1

0.4.1 — First pipeline build (preview)

Changed

• No change in behaviour. This is the first version built and tagged by the release pipeline: the VSIX on the Marketplace is
  the one attached to the GitHub Release, with the same SHA-256.
• The Marketplace page's release-notes link, tags and author name are fixed in the package.
• The NuGet tool package is gone; the MCP server travels inside the extension only.

Debugging via MCP 0.4.0

0.4.0 — Several Visual Studios (preview)

Added

• Several Visual Studios, one agent each. The MCP server picks the Visual Studio whose solution folder relates to the
  folder the agent runs in (the agent in the repository root, the solution in src\, works too); vs_select still
  overrides.
• An agent whose folder is not the solution's must be approved once by the Visual Studio owner (info bar), per
  connection.
• One agent at a time per Visual Studio: the first state-changing command (breakpoint, build, start, attach, ...) takes
  it, a second agent gets in_use. vs_release, a closed connection or Disconnect AI frees it. The status bar and
  vs_instances show who holds it.
• The extension carries the MCP server. When Visual Studio starts it copies the server to
  %LOCALAPPDATA%\DebugViaMcp\bin\<build> and writes a launcher, %LOCALAPPDATA%\DebugViaMcp\debugviamcp.cmd, whose path
  never changes. There is no separate tool to install (the server needs the .NET 10 runtime), updates do not touch a
  server an agent is still running, and uninstalling the extension is never blocked by a running agent.
• Extensions → Debugging via MCP → Set Up AI Agent… opens a window: it checks the .NET runtime and the installed
  server, lists AI clients (Claude Code, Codex, Cursor, another MCP client) and, for the one you pick, shows the command or
  configuration to copy. It runs nothing and changes no client's settings. The separate Copy MCP Setup Command is gone.
• Visual Studio only: Visual Studio Code is not supported, and the documentation says so.
• scripts\reinstall-vsix.ps1 stops a stuck VSIXInstaller after -InstallerTimeoutSeconds (default 180) instead of
  hanging, and refuses to start while another VSIXInstaller runs.
• The Log retention (days) option now also applies to the MCP server's own log files (mcp-*.log), not only to the
  extension's logs and the audit trail.
• debug_start(project) starts the named project and leaves the solution's startup project as it was.
• debug_start, debug_attach and bp_set return warnings when the build is older than the sources; Visual Studio
  offers an optional Build bar (hidden while debugging, gone once the project is up to date).

Fixed

• The out-of-date check no longer compares deps.json / runtimeconfig.json (incremental builds do not rewrite them) with the
  sources: only the assembly and the symbols count. Found in a real Visual Studio run.
• A refused connection approval or a disconnected AI ends the call instead of being asked twice; a read that waited for an
  answer is refused if another agent took the Visual Studio meanwhile.
• debug_status brings the agent's session state in step with Visual Studio after a period in which another agent held it.
• debug_start(project) keeps a "Multiple startup projects" setting intact.
• The Visual Studio taskbar button flashes when a consent question appears while Visual Studio is in the background; the status
  bar shows plain text when Visual Studio 2026 hides its custom status bar panel.
• A timed-out eval explains the 5-second limit and what to do instead.
• Set Up AI Agent never tries to update a running tool (it would fail halfway); it names the running agent sessions.

Changed

• The out-of-date bar says "Debugging via MCP: … is out of date: the built program does not match the sources. Build it now?" and its
  button runs a normal incremental Build of that project (it used to clean and rebuild, which a stale output does not need).
• The consent question bar also starts with "Debugging via MCP:", so both bars show which extension is asking.
• No out-of-date warning and no Build bar while nothing is running and Visual Studio builds by itself as debugging starts (its option
  On Run, when projects are out of date = Always build, the default): it would be a false alarm. They stay when a program is running
  (it keeps its old binary) or when that option is Never build / Prompt to build.
• The product is now called Debugging via MCP. The MCP server (command debugviamcp) travels inside the extension, which
  shows as "Debugging via MCP", and the data folder is %LOCALAPPDATA%\DebugViaMcp.
• The settings moved to Visual Studio's settings experience: Tools → Options → All Settings → Debugging → Debugging via
  MCP. The setup window stays in Extensions → Debugging via MCP (Set Up AI Agent…).
• Settings apply as soon as they change. A stored Mutate = Allow counts only after you confirm it in a dialog (also at
  startup); until then Visual Studio keeps asking, so a value written to the settings file never silently lets the agent
  change program state.
• Two new settings cap how long an agent may keep Visual Studio waiting: Longest wait for a break (debug_start, debug_continue,
  debug_step, debug_run_to, debug_wait; 5–600 s, default 120) and Longest wait for a build (vs_build; 30–1800 s, default 600).
  The agent may ask for less, never for more; a longer build keeps running and the agent can ask again. Together with the existing
  Consent timeout they are in the settings page of Visual Studio.
• Wire protocol 2.3 (additive): the handshake carries the two limits. Older extensions or servers keep the built-in 120 s / 600 s.
• Wire protocol 2.2 (additive). A 2.1 extension keeps working with the 0.4 tool; the new tools then report
  unsupported.
• Break and mode events go only to the agent that holds the Visual Studio.
• vs_instances lists availability (free / in_use), the holder and whether the folder matches.