Short answer
Both answer "who calls this" from a code graph, and on 29 blast-radius cases they find as many callers: 0.86 against 0.84, a tie at this sample size. Pixel answers faster, costs less context on every turn and adds Git history and guarded Git writes. GitNexus queries its graph in Cypher, traces taint and maps API routes, and finds more callers in Ruby.
Side by side
Measured head to head. Pixel and GitNexus on the same cases, on the same machine.
| Measure | Pixel | GitNexus |
|---|---|---|
| Callers found (29 cases) | 0.86 | 0.84 |
| Median answer | 153 ms | 432 ms |
| Mean answer size | 4.5 KB | 11.0 KB |
| Context on every turn | ~4,160 tok | ~19,700 tok |
| Cold index of Pixel's repository | 9.3 s, 8.6 MB | 28.7 s, 184 MB |
| Git history, Git writes | Yes | No |
| Cypher queries, taint analysis, API route maps | No | Yes |
| Callers in Ruby (two repositories) | 0.90 and 0.56 | 1.00 and 0.68 |
| Licence | MIT | PolyForm Noncommercial |
Every figure above is on the benchmarks page, with its sample size, its method and the cases where Pixel loses.
Where GitNexus wins
Cypher queries, taint analysis, API route maps, and callers in Ruby.
How they differ
Both parse a repository into a graph of symbols and calls. GitNexus serves it as MCP tools, whose schemas an agent carries on every turn. Pixel is a command line: the agent runs pixel who-calls or pixel impact in its shell and reads an answer fitted to a budget, and pixel commit-history or pixel push cover the Git side GitNexus leaves out.
Choosing
Pick GitNexus to query the graph in Cypher, trace tainted data or map API routes, or when most of your code is Ruby. Pick Pixel for a lighter context, faster answers, Git history and guarded Git writes, and an MIT licence for commercial use.