{
 "schema_version": 1,
 "generated": "2026-10-26",
 "id": "tencent-wave-mcp--trace-x-value-to-root-cause",
 "repo": "Tencent/wave-mcp",
 "repo_url": "https://github.com/Tencent/wave-mcp",
 "repo_slug": "tencent-wave-mcp",
 "title": "Trace an X value back to its root cause",
 "page_title": "How to trace an X value back to its root cause with Wave MCP",
 "summary": "Follow an unknown (X) value on a signal backward through its drivers to where it starts.",
 "who": "A designer who sees an X on an output after reset and needs to know which upstream logic introduced it.",
 "problem": "Following X propagation by hand through many modules and hierarchy levels takes hours, and the source is often several modules away.",
 "outcome": "A chain of driver nodes, each with its real FST value at that time, ending at the point where the X originates.",
 "steps": [
  "`pip install wave-mcp`",
  "`wave-session --fst sim/dump.fst --top top_tb --filelist rtl.f`",
  "`python -m wave_mcp.server --session sessions/my_module`",
  "`wave-mcp query signal_values --session sessions/my_module --paths top.u_tx.tx_serial` to confirm the X appears on the signal (inferred, check the README)",
  "Call the `trace_x` tool on that signal and time, then open the result with `open_wave_view`"
 ],
 "agent_prompt": "Using the wave-mcp MCP server, run signal_values on <signal_path> to confirm an X value, then call trace_x on that signal at <time>. Return the driver chain from the output back to the earliest node that is X, with each node's value and source location. Verify that the earliest X node has a value of X in the FST at its reported time.",
 "agents": [
  "claude-code",
  "codex",
  "cursor",
  "gemini-cli"
 ],
 "difficulty": "Intermediate",
 "time": "45 minutes",
 "basis": "readme",
 "caveat": "Trace results are only as complete as the netlist: if the filelist, include directories or defines differ from the simulation, the driver chain can be wrong, and Wave MCP warns when the netlist and sources are out of sync.",
 "category": "Software and DevOps",
 "tags": [
  "Software and DevOps"
 ],
 "lang": "python",
 "requirements": [
  "Linux x86_64, where the Python dependencies ship as prebuilt wheels (other platforms need pylibfst built from source)",
  "Python 3.10 to 3.13",
  "A simulation waveform (.fst or .vcd) and the same filelist used to run the simulation",
  "An MCP-capable agent such as Claude Code, Codex, Cursor or Gemini CLI, or a terminal for the CLI"
 ],
 "risk": "none",
 "seen_in_the_wild": false,
 "mentioned_publicly": false,
 "risks": [],
 "best": false,
 "score": 0.9,
 "evidence": [],
 "url": "https://dedupedai.com/use-cases/tencent-wave-mcp/trace-x-value-to-root-cause/",
 "md": "https://dedupedai.com/use-cases/tencent-wave-mcp/trace-x-value-to-root-cause/index.md",
 "disclaimer": "Deduped lists open-source repositories that belong to other people. We do not own, maintain, audit, or vouch for any of them, and a repo appearing here is not an endorsement or a safety check. The use cases, steps, and prompts are written by AI and may be incomplete, outdated, or just wrong. Where a use case is marked \"Seen in the wild\", we link to public posts where someone described something similar, but we have not verified those posts and the use case itself is still our AI's own write-up. Use all of this at your own risk. Only run code, commands, or agents on systems and accounts you are authorized to use, and read the code and every command before you run it, especially anything that touches credentials, files, or the network. Nothing here is professional, security, legal, or financial advice. All trademarks and project names belong to their respective owners, and their use here does not imply affiliation. Content is provided as is, without warranties of any kind. Found a mistake, a safety problem, or something you want removed? Email hello@dedupedai.com and we will look at it promptly.",
 "api": "https://dedupedai.com/api/v1/usecases/tencent-wave-mcp--trace-x-value-to-root-cause.json",
 "api_version": "v1"
}