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/span-coding

Open-code Phoenix spans with PXI-owned notes, recover those notes for axial coding, and promote stable categories into structured annotations. Load this when analyzing spans to discover failure patterns before a taxonomy exists.

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phoenix
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Install
$ npx -y skills add arize-ai/phoenix --skill span-coding --agent claude-code

How it fires

How this skill gets triggered: by you, by Claude, or both.

  • Fires itselfAuto-invocation. Claude auto-loads it when your prompt matches the work.Auto-invocation is when the right skill fires by itself at the right moment, driven by a FLOW.md router and a hook, instead of you invoking it by name. It is the difference between a skill being installed and a skill actually getting used.Read the full definition →
  • You can call itInvoke it directly when you want it.
  • Slash command/span-coding

Context preview

The summary Claude sees to decide when to auto-load this skill.

Open-code Phoenix spans with PXI-owned notes, recover those notes for axial coding, and promote stable categories into structured annotations. Load this when analyzing spans to discover failure patterns before a taxonomy exists.

SKILL.md

span-coding.SKILL.md
name: span-coding
description: >
  Open-code Phoenix spans with PXI-owned notes, recover those notes for axial
  coding, and promote stable categories into structured annotations. Load this
  when analyzing spans to discover failure patterns before a taxonomy exists.
summary: Use PXI span notes for span-level open coding, then recover and group them before structured annotation.

Span Coding

Open coding is the exploratory pass: inspect individual spans and write short, evidence-close notes about concrete behaviors before deciding what the categories are. Axial coding is the synthesis pass: recover those notes, group recurring patterns, name actionable categories, and promote stable categories into structured annotations.

The unit of analysis is always the span. Inspect spans first, avoid taxonomy labels while collecting open notes, and only write structured annotations after the categories have stabilized.

Source of Truth

PXI span notes in Phoenix are the durable source of truth for open codes.

  • Write open codes with `write_span_note`.
  • `write_span_note` always uses identifier `pxi`.
  • Each span has at most one current PXI open-coding note; repeated writes update it.
  • The tool is server-executed and does not require approval.

The virtual bash filesystem is scratch space, not the canonical note store. Use files under `/home/user/workspace/.pxi/coding/` for sampled span lists, interim memos, grouping tables, or draft axial categories when that helps the analysis. Do not dual-write every note to a file by default; recover durable notes from Phoenix when you need to resume.

Open Coding

1. Use the `phoenix-graphql` skill and `phoenix-gql` to inspect spans and surrounding trace context. 2. Read the span input, output, status, attributes, exceptions, and nearby parent/child spans before writing. 3. If the span shows a concrete failure or notable behavior, call `write_span_note` with:

   {"spanId": "<16-char OTel span id>", "note": "<specific observation>"}

4. Write what you saw, not the category you think it belongs to. Good notes cite the observed behavior: "Retriever returned onboarding docs for a cancellation question." Weak notes jump straight to categories: "retrieval_failure". 5. Skip correct spans. Open coding is a signal-building pass, not a requirement to annotate every span.

Do not use `batch_span_annotate` during open coding unless the user has already supplied a stable rubric. Free-form PXI notes come first; structured annotation comes later.

Recover PXI Span Notes

Recover PXI notes with a GraphQL query over `Project.spans`, then filter `spanNotes` locally to `identifier == "pxi"`. There is no `list_span_notes` tool.

query RecoverPxiSpanNotes($projectId: ID!, $first: Int = 50, $after: String) {
  node(id: $projectId) {
    ... on Project {
      spans(first: $first, after: $after) {
        edges {
          node {
            spanId
            name
            trace { traceId }
            spanNotes {
              identifier
              explanation
              createdAt
              updatedAt
            }
          }
        }
        pageInfo {
          hasNextPage
          endCursor
        }
      }
    }
  }
}

Paginate until `hasNextPage` is false or the recovered sample is sufficient. Keep only notes whose `identifier` is exactly `pxi`. When a span has no PXI note, treat it as uncoded.

Axial Coding

Use recovered PXI notes as the raw material for axial coding.

1. Group notes that describe the same underlying failure. 2. Name categories for likely causes or fixes, not generic symptoms. 3. Check project annotation configs before creating new structured labels. 4. Use `batch_span_annotate` only after the categories and labels stabilize. 5. Keep optional bash sidecars focused on analysis handoff: grouping tables, current counts, and draft taxonomies. The DB notes remain the durable open-coding record.

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