manage-omp-tracing

name

manage-omp-tracing

description

Set up and configure Arize tracing for Oh My Pi (omp) terminal coding sessions. Use when users want to set up tracing, configure Arize AX or Phoenix for Oh My Pi, enable/disable omp tracing, or troubleshoot tracing issues. Triggers on "set up omp tracing", "configure Arize for Oh My Pi", "configure Phoenix for omp", "enable omp tracing", "setup-omp-tracing", or any request about connecting omp / Oh My Pi to Arize or Phoenix for observability.

Setup omp Tracing

Configure OpenInference tracing for Oh My Pi (omp) terminal coding sessions to Arize AX (cloud) or Phoenix (self-hosted). Like opencode, omp loads its extensions in-process inside its Bun runtime — there is no per-event subprocess. The integration ships as a small TypeScript hook shim that forwards omp's once-fired lifecycle events to a Python handler (arize-hook-omp) which emits spans. Spans are sent directly to the backend from the handler — no separate buffer/collector service is required.

How to Use This Skill

This skill follows a decision tree workflow. Start by asking the user where they are in the setup process:

1. Is the harness already installed?

   • Check ~/.omp/extensions/arize-tracing.ts for the Arize hook shim
   • Check ~/.omp/agent/settings.json for the shim's path in the extensions array
   • Check ~/.arize/harness/config.json for the harnesses.omp block
   • If all are present -> Jump to Validate or Troubleshoot

2. Do they already have credentials?

   • Yes -> Jump to Configure Settings
   • No -> Continue to step 3

3. Which backend do they want to use?

   • Phoenix (self-hosted) -> Go to Set Up Phoenix
   • Arize AX (cloud) -> Go to Set Up Arize AX

4. Are they troubleshooting?

   • Yes -> Jump to Troubleshoot

Important: Only follow the relevant path for the user's needs. Don't go through all sections.

Set Up Phoenix

Phoenix is self-hosted. No Python dependencies are needed for tracing -- spans are sent directly via send_span() using stdlib urllib.

Install Phoenix

Ask if they already have Phoenix running. If not, walk through:

# Option A: pip
pip install arize-phoenix && phoenix serve

# Option B: Docker
docker run -p 6006:6006 arizephoenix/phoenix:latest

Phoenix UI will be available at http://localhost:6006. Confirm it's running:

curl -sf http://localhost:6006/v1/traces >/dev/null && echo "Phoenix is running" || echo "Phoenix not reachable"

Then proceed to Configure Settings with the Phoenix endpoint.

Set Up Arize AX

Arize AX is available as a SaaS platform or as an on-prem deployment. Users need an account, a space, and an API key.

First, ask the user: "Are you using the Arize SaaS platform or an on-prem instance?"

• SaaS -> Uses the default endpoint (otlp.arize.com:443). Continue below.
• On-prem -> The user will need to provide their custom OTLP endpoint (e.g., otlp.mycompany.arize.com:443). Ask for it and note it for the Configure Settings step.

1. Create an account

If the user doesn't have an Arize account:

• SaaS: Sign up at https://app.arize.com/auth/join
• On-prem: Contact their administrator for access to the on-prem instance

2. Get Space ID and API key

Walk the user through finding their credentials:

1. Log in to their Arize instance (https://app.arize.com for SaaS, or their on-prem URL)
2. Click Settings (gear icon) in the left sidebar
3. The Space ID is shown on the Space Settings page
4. Go to the API Keys tab
5. Click Create API Key or copy an existing one

Both api_key and space_id are required for the shared config.

No Python dependencies are needed. Both Phoenix and Arize AX use HTTP/JSON -- no additional Python dependencies are needed.

Then proceed to Configure Settings. If the user is on an on-prem instance, remind them to provide their custom endpoint.

Configure Settings

Important: Users must run this setup before tracing will work. The send_span() function requires ~/.arize/harness/config.json to exist for backend credential resolution.

Ask the user for:

1. Backend choice: Phoenix or Arize AX
2. Credentials (only if no existing config):
   • Phoenix: endpoint URL (default: http://localhost:6006), optional API key
   • Arize AX: API key and Space ID
3. OTLP Endpoint (Arize AX only, optional): For hosted Arize instances using a custom endpoint. Defaults to otlp.arize.com:443.
4. Project name (optional): defaults to "omp", stored under harnesses.omp.project_name
5. User ID (optional): Set ARIZE_USER_ID env var to identify spans by user (useful for teams)

Write the config

The config file at ~/.arize/harness/config.json is the single source of truth for backend credentials and per-harness settings. Create the directory structure if needed: mkdir -p ~/.arize/harness/{bin,run,logs,state/omp}

Important: read-merge-write. If ~/.arize/harness/config.json already exists, read it first, then merge in the new or updated fields (e.g., add/update the harnesses.omp entry) while preserving existing backend credentials. Only prompt for backend credentials if no existing config is found.

Phoenix:

{
  "harnesses": {
    "omp": {
      "project_name": "omp",
      "target": "phoenix",
      "endpoint": "<endpoint>",
      "api_key": ""
    }
  }
}

If Phoenix requires authentication (e.g. Phoenix Cloud), set the API key here under api_key, or export PHOENIX_API_KEY in the environment — it is sent as a Authorization: Bearer <key> header. The env var takes precedence over the config value. Leave api_key: "" for an unauthenticated local Phoenix.

Arize AX:

{
  "harnesses": {
    "omp": {
      "project_name": "omp",
      "target": "arize",
      "endpoint": "otlp.arize.com:443",
      "api_key": "<key>",
      "space_id": "<id>"
    }
  }
}

If the user has a custom OTLP endpoint, set it in harnesses.omp.endpoint.

Activate the omp hook

omp does not auto-discover an extensions directory — the extensions key in ~/.omp/agent/settings.json is an explicit array of file/dir paths omp loads (hook docs). The installer drops the Arize hook shim at ~/.omp/extensions/arize-tracing.ts and registers that absolute path in the extensions array, e.g.:

{ "extensions": ["/Users/me/.omp/extensions/arize-tracing.ts"] }

omp picks up the registered extension on next launch.

Install or reinstall via the installer:

./install.sh omp

To uninstall:

./install.sh uninstall omp

Uninstall removes the shim's path from the extensions array, deletes the hook file at ~/.omp/extensions/arize-tracing.ts (only if it carries the Arize header marker — the installer never touches the user's own extensions), and removes the harnesses.omp block from ~/.arize/harness/config.json.

Validate

1. Config exists: Run cat ~/.arize/harness/config.json to verify the config file exists and has correct backend credentials under harnesses.omp.
2. Phoenix (if applicable): Run curl -sf <endpoint>/v1/traces >/dev/null to check connectivity.
3. Hook installed: Verify ~/.omp/extensions/arize-tracing.ts exists and starts with the Arize header marker.
4. Hook registered: Verify the shim's absolute path appears in the extensions array of ~/.omp/agent/settings.json (omp does not auto-discover — registration is required).
5. Handler entry point: Verify the handler binary exists at ~/.arize/harness/venv/bin/arize-hook-omp (or ~/.arize/harness/venv/Scripts/arize-hook-omp.exe on Windows). The shim spawns this binary by absolute path — it does not rely on PATH resolution. install.sh installs it as a venv entry point.

Confirm

Tell the user:

• Config saved to ~/.arize/harness/config.json
• omp hook shim installed at ~/.omp/extensions/arize-tracing.ts
• Shim path registered in the extensions array of ~/.omp/agent/settings.json — omp requires explicit registration (no auto-discovery)
• Spans are sent directly to the backend from the handler — no background process needed
• After saving, open a new omp session and traces will appear in their Phoenix UI or Arize AX dashboard under the project name
• Mention ARIZE_DRY_RUN=true to test without sending data (set as env var before launching omp)
• Mention ARIZE_VERBOSE=true for debug output
• Errors and handler stderr are always written to ~/.arize/harness/logs/omp.log (the adapter redirects Python stderr there via ARIZE_LOG_FILE); set ARIZE_VERBOSE=true in the shell before launching omp to also capture routine handler activity (event dispatch, span emits, state transitions)
• Toggle tracing on/off via ARIZE_TRACE_ENABLED env var (must be exported in the user's shell before launching omp — the shim and handler inherit host env vars)
• Tail the log file at ~/.arize/harness/logs/omp.log for real-time debugging
• Mention ARIZE_TRACE_DEBUG=true to dump raw event payloads under ~/.arize/harness/state/debug/ (files are named omp_before_agent_start_<ts>.json / omp_turn_end_<ts>.json / omp_agent_end_<ts>.json / omp_session_shutdown_<ts>.json) for inspection

Architecture (How spans are produced)

omp loads its extensions in-process inside its Bun runtime (hook docs). Unlike opencode, omp exposes rich, once-fired lifecycle events that already carry final, structured data, so the Arize integration is a stateful event-forward (no snapshot reconciliation, no dedup). It is split into two pieces:

1. TypeScript hook shim at ~/.omp/extensions/arize-tracing.ts. A dumb bridge. On a whitelist of lifecycle events — before_agent_start (the prompt), turn_end (the completed AssistantMessage with inline token usage + model, plus that turn's toolResults), agent_end (run finished), and session_shutdown — it spawns arize-hook-omp detached and pipes the event payload to stdin. The shim contains no tracing logic and never blocks omp's event loop.
2. Python event handler (arize-hook-omp). A small state machine keyed by session id. It dispatches on payload["type"], accumulates per-session state, and emits Turn/LLM/TOOL spans on receipt. Pairs each ToolCall with its ToolResultMessage by id to build TOOL spans with both input args and output.

Span tree

Each trace covers one agent run (one user prompt → the agent's internal turn/tool-use loop → its final answer). A run usually contains several model calls; one trace covers all of them. The tree:

Span	Kind	Description
Turn	CHAIN	Root span. input.value is the user prompt (from before_agent_start); output.value is the final assistant message's text. One per agent run.
LLM: <model>	LLM	Child of Turn. One per turn_end (one per model call in the loop). Carries llm.model_name, llm.provider, prompt/completion/reasoning token counts, cache read/write tokens, and llm.cost. omp surfaces token usage inline on the assistant message, so it is captured.
<tool>	TOOL	Child of Turn. One per ToolResultMessage in a turn_end, paired with its originating ToolCall by id. Records tool.name, redacted input args + output, and tool-specific attributes; errors are recorded with span status.

Troubleshoot

Common issues and fixes for omp:

Problem	Fix
Traces not appearing	Verify config exists: cat ~/.arize/harness/config.json. Check handler log: tail -20 ~/.arize/harness/logs/omp.log. Confirm the hook is in place: ls ~/.omp/extensions/arize-tracing.ts.
Hook not loading	omp does not auto-discover an extensions dir. Confirm the shim's absolute path is in the extensions array of ~/.omp/agent/settings.json, then restart omp and check its CLI output for extension errors.
Handler entry point missing	The shim spawns the handler by absolute path; verify the binary exists at ~/.arize/harness/venv/bin/arize-hook-omp (or ~/.arize/harness/venv/Scripts/arize-hook-omp.exe on Windows). Rerun ./install.sh omp to reinstall the venv entry point.
Missing LLM or tool spans	Spans emit on turn_end (one LLM span per model call, one TOOL span per tool result). If a turn hasn't completed yet, its spans won't appear until the event fires. Wait for the agent run to finish (agent_end).
Trace missing the final answer	output.value on the Turn span comes from the final assistant message. Confirm the run reached agent_end.
Phoenix unreachable	Verify Phoenix is running: curl -sf <endpoint>/v1/traces
Want to test without sending	Set ARIZE_DRY_RUN=true env var before launching omp
Want verbose logging	Set ARIZE_VERBOSE=true env var before launching omp
Want raw event payloads for inspection	Set ARIZE_TRACE_DEBUG=true env var; payloads land under ~/.arize/harness/state/debug/ as omp_before_agent_start_<ts>.json / omp_turn_end_<ts>.json / omp_agent_end_<ts>.json / omp_session_shutdown_<ts>.json
Wrong project name	Set harnesses.omp.project_name in ~/.arize/harness/config.json (default: "omp")