A TypeScript stack trace is a list of file:line pairs, which is exactly what Atlas's read tool consumes. To trace a runtime bug, paste the trace and have Atlas read each frame at its reported offset, then grep for the error message string to find where the Error is actually constructed, which is usually more informative than the top frame. Atlas validates offsets against the current file, so a trace from an older bundle fails loudly with "Offset <n> is out of range for this file" instead of pointing confidently at the wrong line of src/services/order.ts. From there the lsp tool's findReferences operation shows which callers can reach the failing function with the bad input, and you fix with edit and lock the behavior in with a vitest regression test. No debugger attached, no source-map guessing.
How do you trace a TypeScript stack trace to the responsible line without a debugger?
A TypeScript stack trace is a list of file:line pairs, and Atlas's read tool consumes exactly that. Paste the trace, and Atlas reads each frame at its reported offset, opening src/services/order.ts at the line the trace names rather than reading the whole 600-line module into context.
Attaching a debugger to reproduce a production TypeScript bug is often impossible: the failure happened once, on a machine you do not have, under a load you cannot recreate. The stack trace is the only evidence, and it is structured evidence. Atlas walks it frame by frame, reading each file at the offset the trace reports, which reconstructs the call path from the top frame down through your service and controller layers. Because Atlas indexes code by AST declarations using tree-sitter rather than blind line windows, following a frame into a helper gives you the whole function, not a truncated window that cuts the closure in half.
What does Offset is out of range mean when reading a TypeScript stack trace in Atlas?
Offset out of range is Atlas's read tool telling you the TypeScript stack trace came from a different build than the code on disk. Step 2 of the documented workflow is to re-read the file from the top before trusting any line number, because the offsets in the trace no longer match src/.
Stale traces are the quiet killer of TypeScript debugging. A trace says src/api/handlers.ts:412, you open line 412 in your working tree, and it is a blank line inside an unrelated function, but you have already started building a theory around it. Atlas refuses to play along: the read tool checks the offset against the file's actual length and reports "Offset <n> is out of range for this file" when the trace and the source disagree. That error is a signal, not an obstacle. Re-read the file from the top, confirm the function names in the trace still exist, and only then trust any line number the trace gives you.
Why does Atlas grep for the error message instead of trusting the top stack frame?
Atlas greps the TypeScript source for the error message string, step 3 of the documented trace workflow, because the line that throws is rarely the line that is wrong. In a pnpm workspace the top frame is often a shared assertion helper, while the Error's construction site carries the context explaining the bad input.
The top frame of a TypeScript stack trace tells you where the process gave up, not where the mistake was made. A throw new TypeError inside a validation utility appears at the top of a hundred different traces. Grepping the source for the literal message string finds the one place that message is constructed, and that construction site usually sits right next to the check that failed and the variable that failed it. Atlas searches code with hybrid semantic and keyword retrieval fused by reciprocal rank fusion, so an exact grep for the message and a semantic query about the behavior both converge on the same TypeScript module.
How do you find which callers can reach a failing TypeScript function with bad input?
Atlas uses the lsp tool's findReferences operation on the failing TypeScript function. In a 2026 TypeScript project with a tsconfig.json and path aliases, findReferences walks the symbol graph and surfaces callers that a text grep would miss, including imports routed through an alias like @/services rather than a relative path.
Knowing the responsible line is only half the trace. The other half is which caller passed the bad value, and TypeScript path aliases make that hard to grep for: the same function may be imported as ../../services/order in one file and @/services/order in another. The lsp tool's findReferences operation queries the language server, so it resolves through tsconfig.json paths and returns every real callsite. Atlas then reads those callers and narrows to the ones that can actually construct the input shape the trace implies, which turns a stack trace into a bounded set of suspects.
How do you lock in the fix with a vitest regression test?
Atlas fixes the TypeScript bug with the edit tool, then adds a vitest regression test reproducing the trace's input, which is step 5 of the documented workflow. Atlas computes a unified diff for every file edit and surfaces it for approval before writing, so both the fix and the new spec get reviewed.
A traced bug without a regression test is a bug that will be re-traced. Once the responsible line in src/services/order.ts is identified, Atlas applies the fix with edit and writes a vitest spec that feeds the same malformed input the trace implies, asserting the corrected behavior. prettier keeps the new spec consistent with the rest of the repo, and pnpm runs the suite. Atlas's documented TypeScript setup is to run atlas in a project with a tsconfig.json, let it read your type definitions, path aliases, and strictness settings, and approve the diff. Atlas snapshots file changes as git patches, so a fix that turns out to be wrong is diffable and reversible.
Step by step
- 01Run atlas in a TypeScript project that has a tsconfig.json, so Atlas can read your type definitions, path aliases, and strictness settings.
- 02Paste the production stack trace and have Atlas read each frame's file at the reported offset, using the read tool rather than loading whole modules.
- 03If read reports "Offset <n> is out of range for this file", the trace came from a different build; re-read the file from the top before trusting any line number in it.
- 04Grep the TypeScript source for the exact error message string to find where the Error is constructed, which is usually more informative than the top frame.
- 05Run the lsp tool's findReferences operation on the failing function to enumerate every caller, including imports routed through a tsconfig.json path alias that a grep would miss.
- 06Narrow to the callers that can actually produce the bad input the trace implies, reading each one with the read tool.
- 07Fix the responsible line with the edit tool and review the unified diff Atlas surfaces for approval before it writes.
- 08Add a vitest regression test that feeds the same input, run the suite through pnpm, and run prettier over the new spec so the trace cannot recur silently.
Frequently asked questions
- how to debug a typescript production stack trace without a debugger
- Paste the trace into Atlas. A TypeScript stack trace is a list of file:line pairs, and Atlas's read tool reads each frame at its reported offset. Atlas then greps for the error message string, walks callers with the lsp tool's findReferences operation, and fixes with edit.
- why does atlas say Offset is out of range for this file
- Atlas's read tool validates every offset against the current file. "Offset <n> is out of range for this file" means the stack trace came from a different build than the code on disk. Re-read the file from the top and do not trust the trace's line numbers until you confirm the functions still exist.
- should i trust the top frame of a typescript stack trace
- Not on its own. The top frame is where the process gave up, often a shared assertion or validation helper. Grepping for the error message string finds where the Error is actually constructed, which sits next to the failed check and the bad variable.
- how do i find every caller of a typescript function with path aliases
- Use the lsp tool's findReferences operation. It queries the language server, so it resolves imports through tsconfig.json path aliases like @/services as well as relative paths. A plain grep misses callers that import the same symbol under a different specifier.
- does atlas write a vitest test after fixing a bug
- The documented workflow ends with fixing via edit and adding a regression test so the trace cannot recur silently. vitest is the test runner in Atlas's TypeScript toolchain, alongside pnpm as the package manager and prettier as the formatter.
- can atlas read my tsconfig strictness settings
- Yes. Atlas's documented TypeScript setup is to run atlas in a project with a tsconfig.json and let it read your type definitions, path aliases, and strictness settings, then ask it to tighten types, remove any, or generate typed API clients and approve the diff.
- how do i review an edit atlas makes to a typescript file
- Atlas computes a unified diff for every file edit and surfaces it for approval before writing, so a change to src/services/order.ts is shown as a patch first. Atlas also snapshots file changes as git patches, so an approved fix can still be diffed and rolled back.
- why does atlas read a whole function instead of a few lines around the stack frame
- Atlas indexes code by AST declarations using tree-sitter, not blind line windows. Following a TypeScript stack frame into a helper returns the whole declaration rather than an arbitrary window that could cut a closure or a type guard in half.
Try Atlas in your terminal
The terminal-native AI coding agent. Free core, single binary.
Install AtlasRelated guides
Trace a Runtime Bug from a Stack Trace with Atlas in 2026
How to trace a runtime bug from a stack trace with Atlas in 2026: read each frame at its offset, grep for the error string, and use the lsp tool to find callers.
Atlas for TypeScript in 2026
In 2026, TypeScript developers leverage Atlas, the terminal-native AI coding agent, to enhance productivity. Atlas understands your types, ensures code quality, and offers robust safety features.
Run Atlas Headless in CI in TypeScript with Atlas (2026)
Run Atlas headless in CI on a TypeScript repo in 2026: atlas run is non-interactive by default, supports --format json, and needs pre-approved permissions to reach vitest.
Run the Test Suite and Triage the Failures in TypeScript with Atlas (2026)
Turn a wall of red vitest output into a ranked list of root causes in 2026: Atlas truncates at 2000 lines, saves the full log, and greps it into a todowrite triage list.
Self-Review Your Working Diff Before Committing in TypeScript with Atlas (2026)
How to self-review an uncommitted TypeScript diff with Atlas in 2026: read the working diff, grep for leftovers, revert from snapshots, then run vitest and prettier.
Rename a symbol across the repo in TypeScript with Atlas (2026)
Rename a TypeScript symbol across the whole repo in 2026 with Atlas: findReferences for the true callsite list, grep for strings the compiler cannot see, then vitest.
Add a Regression Test for a Bug Fix in TypeScript with Atlas (2026)
Red first, then green: how Atlas adds a TypeScript regression test in 2026, proving it fails with vitest, applying the fix with edit, and re-running the same command.
Migrate a Deprecated API Across Every TypeScript Callsite With Atlas (2026)
Move a TypeScript codebase off a deprecated function without missing a caller: Atlas enumerates with lsp findReferences, tracks with todowrite, patches with apply_patch.