Tracing for Devin CLI records the work Devin does after each agent response as a trace. Devin’s hooks carry almost no data, so the tracer uses them only as a signal and reads the model calls, tokens and tool calls from the local session database Devin keeps while you work. This page covers the install, what a trace looks like, and the limits worth knowing about.

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Install

On macOS or Linux:
On Windows:
The installer prompts for your license key and project name, stores them in ~/.atatus/harness/config.json, and registers a command hook under the Stop and SessionEnd events in Devin’s user config file. Each hook has a 30 second timeout. If the config file already exists, the installer keeps your other settings and hooks and adds its own entry once, so running it again does not create duplicates. Devin accepts comments in its config, and the installer drops them when it rewrites the file. If the file cannot be parsed, the installer stops without changing it.

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What gets captured

Each trace is a three-level tree. Every model call is its own span, and the tools it requested sit inside it: A trace reads as a sequence of model calls, each with its tools beneath it:
Tokens live only on the LLM call spans. The root carries none, so adding up a trace counts every token once. A figure for the whole interaction is the total across its model calls.
All traces from one Devin session share the same session.id, so Atatus groups them as one session. Cache read and cache write tokens are recorded when Devin reports them, and cached tokens are counted inside the prompt total. A count that Devin reports as zero is left off the span. When a generation has no visible text, the span shows its reasoning as the output so it still renders.

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How the session is read

When Stop fires, the hook finds the session and builds spans from what is new since the last time it ran:
  1. It takes the project directory from DEVIN_PROJECT_DIR, or the current directory when that is not set, and picks the most recently active Devin session whose working directory matches it.
  2. It opens Devin’s sessions.db read-only and reads the assistant messages that carry usage metrics. Devin copies earlier messages as a conversation grows, so the tracer treats each request ID as one generation and sends it once, even when the copies appear under several rows.
  3. It sends the new generations as one trace and records their request IDs so they are not sent again.
SessionEnd runs the same step, so a last turn that was interrupted is still sent. Spans are sent straight from the hook process, so there is no separate collector or buffer service to run. A hook failure never stops Devin: errors are written to the log and the hook exits cleanly.

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Where things live

On Windows the hook config lives under %APPDATA%, but the session database stays under your user profile at %USERPROFILE%\.local\share\devin\cli.

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Known limits

  • Tool results are empty. The session database does not expose a tool’s result while the session is live, so a Tool span records the tool name and arguments but no output.
  • Tool timing matches the model call. A Tool span uses the start and end of the model call that requested it, so it does not show how long the tool itself ran.
  • One trace covers every new generation. Each Stop sends all generations not yet sent for that session. The root shows only the latest prompt, so a trace that spans several prompts, such as the first one after you install into an existing session, groups them under that one prompt.
  • Sessions are matched by directory. If two Devin sessions are active in the same working directory, the most recently active one is traced.
  • Content settings apply. Prompts, reasoning, tool arguments and tool content are only recorded when your logging settings allow them.

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Uninstall

This removes only the Atatus hook from the Stop and SessionEnd events in Devin’s config, drops an event or the hooks key if it ends up empty, and leaves the rest of the file untouched. See Uninstall for the full-wipe option.