how to audit a large c++ codebase with an ai agent

Split the repo into independent slices by CMake target, then launch one Atlas task per slice with subagent_type explore. The subagents run in their own sessions, so hundreds of headers never enter your main context, and only their findings come back to be merged into a todowrite list.

what is the difference between the explore and general subagent in atlas

The explore subagent is deny-by-default and read-only, which makes it the right one for an audit where nothing should change. The general subagent can act, so it is the one to use when a C++ slice must actually run a command like ctest or resolve packages with vcpkg.

can atlas subagents run in parallel

Yes. Atlas fans out work to subagents that can run in the foreground or in parallel background sessions. Issue the task calls together so a repo split into 6 slices audits in roughly the time of the slowest slice rather than the sum of all 6.

what happens if an atlas subagent fails mid-audit

The task tool surfaces the child's error text verbatim if it fails, and reports Task cancelled if it was cancelled. A C++ audit slice that dies on a missing toolchain file produces a visible failure rather than a silently empty finding set.

how do I find raw pointers that should be smart pointers across a c++ repo

Make it one audit rule and give it its own slice. Have the explore subagents glob the .cpp and .hpp files and grep for raw new and delete, then merge the hits into a todowrite list and modernize them to smart pointers with edit in the main session, verifying with GoogleTest via ctest.

what does atlas need to work on a c++ project

Run atlas in a project with a CMakeLists.txt. Atlas reads your headers, translation units, and build targets, and can modernize to smart pointers or add GoogleTest cases, showing you the diff to review before anything is written.

Audit a repo with parallel subagents in C++ with Atlas (2026)

Atlas audits a large C++ repository by fanning the sweep out to subagents instead of dragging every translation unit through one session. Atlas's task tool launches subagents in their own sessions, so their file dumps never enter your context and only their conclusions come back, which is the difference between auditing 400 headers and running out of room after 40. For an audit specifically, use subagent_type explore, which is deny-by-default and read-only, so a sweep for raw new and delete across your src and include trees cannot modify a single .cpp file. Findings merge into one todowrite list, and fixes happen in the main session with edit, verified by GoogleTest via ctest.

How do you audit a large C++ repo without blowing the context window?

Atlas's task tool launches subagents in their own sessions, so the contents of 300 header files never enter the main context. Only each subagent's conclusion comes back. For a C++ repo with a deep include tree and heavy templates, that separation is what makes a whole-repo audit possible at all.

C++ punishes naive whole-repo reading harder than most languages. A single translation unit pulls in a header cascade, template definitions live in headers rather than .cpp files, and a mid-sized project can have thousands of files under include/ and src/. Reading them all into one session is not a strategy. Atlas's task tool spawns each audit slice as a separate subagent with its own context, and only the final message, the findings, returns. The five Atlas tools this workflow uses are task, todowrite, grep, glob, and edit. Atlas fans out work to subagents that can run in the foreground or in parallel background sessions, so the sweep proceeds concurrently rather than file by file.

Why use the explore subagent for a C++ audit instead of general?

Atlas offers 2 subagent types for an audit, and explore is the right one for C++: it is deny-by-default and read-only, so nothing changes while it sweeps. The general subagent can act, so reserve it for the slices that must run a command, such as configuring vcpkg or invoking ctest to confirm a target still builds.

An audit is a read operation, and the safest way to guarantee a read stays a read is to remove the ability to write. Atlas's explore subagent is deny-by-default and read-only, so a subagent sweeping include/net/ for missing virtual destructors cannot edit a header, delete a build artifact, or run a command that mutates the CMake cache. The general subagent, by contrast, can act, which is what you want when a slice needs to build a target with ctest or resolve a package with vcpkg to see the real preprocessor state. Every Atlas tool call is permission-gated against allow, ask, and deny rules before it runs, so even the general subagent runs inside your policy.

How do you split a C++ codebase into non-overlapping audit slices?

Atlas audits a C++ repo in independent slices so the subagents do not overlap, and there are 3 natural ways to cut them: by directory, by package, or by rule. A CMake project already gives you the seams, since each add_library and add_executable target in CMakeLists.txt bounds a coherent set of translation units and headers.

Overlap is waste, and worse, it produces duplicate findings that have to be reconciled. C++ projects hand you clean seams for free. Slice by CMake target, so one subagent audits the target defined by src/net/CMakeLists.txt and another audits src/codec/. Slice by directory, so include/ and src/ are swept separately. Or slice by rule, so one subagent looks only for raw owning pointers that should be std::unique_ptr, another only for missing virtual destructors on polymorphic base classes, and a third only for functions taking std::string by value where a const reference would do. Atlas uses glob to enumerate the .cpp and .hpp files in each slice and grep to find candidate patterns within them.

How do you run C++ audit subagents concurrently rather than one at a time?

Issue the task calls together so the C++ audit subagents run concurrently rather than one after another. A repo split into 6 CMake-target slices audits in roughly the time of the slowest slice, not the sum of all 6, because Atlas fans out work to subagents in parallel background sessions.

Sequential subagents give you the context savings but not the speed. Launching them together gives you both. In Atlas, that means issuing the task calls in one go rather than waiting for each to return before dispatching the next. For a C++ audit the win is real, because each slice is doing genuinely slow work: globbing a deep include tree, grepping for patterns across template-heavy headers, and reading enough of each hit to judge whether it is a true positive. Atlas is a terminal-native TUI rendered with SolidJS through the OpenTUI renderer, so the parallel sessions are visible while they run rather than hidden behind a spinner.

What happens when a C++ audit subagent fails or is cancelled?

Atlas's task tool surfaces the child subagent's error text verbatim if it fails, and reports Task cancelled if it was cancelled, so there are 2 legible outcomes rather than silence. A C++ audit slice that dies partway through a header sweep produces a visible, readable failure rather than a quietly missing set of findings.

Silent partial results are the real danger in a parallel audit, because a slice that quietly returned nothing looks identical to a slice that found nothing. Atlas removes that ambiguity: a failed subagent's error text comes back verbatim, and a cancelled one comes back as Task cancelled. For an audit sweeping a vcpkg-managed C++ project, this matters when a slice fails for environmental reasons, a missing toolchain file, an unconfigured CMake cache, that have nothing to do with the code being audited. You re-run that slice rather than shipping an audit with a hole in it and no indication where the hole is.

How do you merge subagent findings and fix them safely in C++?

Merge every subagent's findings into one todowrite list and fix them in the main session with edit. Atlas computes a unified diff for every file edit and surfaces it for approval before writing, so a sweep that proposes converting 30 raw pointers to std::unique_ptr is reviewed hunk by hunk.

Fixing in the main session, not in the subagents, is deliberate. The explore subagents were read-only precisely so that nothing changed while the picture was still incomplete. Once every slice has reported, the findings become a single todowrite list, and the main session works it with edit. In C++ the verification step is non-negotiable, because a change to a header recompiles everything that includes it: run GoogleTest via ctest after each batch of edits, and let clang-format normalize the touched files against your .clang-format so the diff shows semantic changes and not brace shuffling. Atlas snapshots file changes as git patches, so a bad modernization can be rolled back.

Step by step

01Run atlas in a project with a CMakeLists.txt so Atlas can read your headers, translation units, and build targets.
02Split the audit into independent slices so the subagents do not overlap, using CMake targets, the include/ and src/ split, or one rule per slice.
03Launch one task per slice with subagent_type explore for a read-only sweep, or general when the subagent must also run vcpkg or ctest.
04Issue the task calls together so the slices run concurrently rather than one after another.
05Have each subagent use glob to enumerate the .cpp and .hpp files in its slice and grep to find candidate patterns such as raw new and delete.
06Collect each subagent's final message; the task tool surfaces the child's error text verbatim if it fails, and Task cancelled if it was cancelled.
07Merge the findings into one todowrite list and fix them in the main session with edit, reviewing the unified diff for each file.
08Run GoogleTest via ctest after each batch of fixes, and run clang-format on the touched files so the diff shows semantics, not formatting.

Frequently asked questions

how to audit a large c++ codebase with an ai agent: Split the repo into independent slices by CMake target, then launch one Atlas task per slice with subagent_type explore. The subagents run in their own sessions, so hundreds of headers never enter your main context, and only their findings come back to be merged into a todowrite list.
what is the difference between the explore and general subagent in atlas: The explore subagent is deny-by-default and read-only, which makes it the right one for an audit where nothing should change. The general subagent can act, so it is the one to use when a C++ slice must actually run a command like ctest or resolve packages with vcpkg.
how do I stop an ai agent from running out of context on a big repo: Fan the work out with Atlas's task tool. Subagents launch in their own sessions, so their file dumps never enter your context and only their conclusions come back. In a C++ project with a deep include tree, that is what makes a whole-repo sweep possible.
can atlas subagents run in parallel: Yes. Atlas fans out work to subagents that can run in the foreground or in parallel background sessions. Issue the task calls together so a repo split into 6 slices audits in roughly the time of the slowest slice rather than the sum of all 6.
what happens if an atlas subagent fails mid-audit: The task tool surfaces the child's error text verbatim if it fails, and reports Task cancelled if it was cancelled. A C++ audit slice that dies on a missing toolchain file produces a visible failure rather than a silently empty finding set.
how do I find raw pointers that should be smart pointers across a c++ repo: Make it one audit rule and give it its own slice. Have the explore subagents glob the .cpp and .hpp files and grep for raw new and delete, then merge the hits into a todowrite list and modernize them to smart pointers with edit in the main session, verifying with GoogleTest via ctest.
will atlas modify my c++ code during an audit: Not if you use the explore subagent, which is deny-by-default and read-only. When you do fix the findings, Atlas computes a unified diff for every file edit and surfaces it for approval before writing, and snapshots the changes as git patches so they can be rolled back.
what does atlas need to work on a c++ project: Run atlas in a project with a CMakeLists.txt. Atlas reads your headers, translation units, and build targets, and can modernize to smart pointers or add GoogleTest cases, showing you the diff to review before anything is written.

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