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PXI — Phoenix Intelligence
PXI is in beta. It can and will make mistakes, and it should be used with care — especially on production data. Agent assistance is opt-in and controllable: see You stay in control.
PXI (pronounced “pixie”, short for Phoenix Intelligence) is an AI engineering agent built into Phoenix. Instead of manually digging through traces, prompts, evaluations, and experiments, you hand the investigation to an agent that already understands the context you are looking at — the trace you opened, the prompt you are editing, the filters you applied. Think of it as a coding agent, but pointed at your observability data instead of a codebase. It inspects traces, investigates failures, iterates on prompts, runs experiments, authors evaluators, annotates spans, and navigates Phoenix for you.

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Get started

1

Configure a model

PXI needs a model to talk to. Set credentials for at least one provider (OPENAI_API_KEY, ANTHROPIC_API_KEY, GEMINI_API_KEY, AWS Bedrock credentials, or a custom provider under Settings → Models). See Setup for the validated model list.
2

Open PXI and accept the consent gate

Open the assistant from any Phoenix page. The first time, you review the session-trace settings and acknowledge to enable the chat surface for your browser.
3

Ask it something

From a failing trace, try “why did this fail?” From the prompt playground, try “make this prompt more robust to empty input.” PXI uses the page you are on as context — no need to paste IDs or copy data.

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What it does

  • Drives the product — navigates, filters, and pivots through your Phoenix data the same way you would.
  • Investigates failures — walks failing traces and proposes root causes instead of leaving you to grep through spans.
  • Iterates on prompts — reads, edits, and tests playground prompts, with every change shown as a diff you approve.
  • Reasons over your data — a sandboxed runtime lets PXI query your Phoenix instance to answer questions evals and dashboards cannot.
  • Knows the product — Phoenix’s own documentation is wired in as a first-class source, so answers are grounded rather than guessed.
PXI is context-aware: it has access to the history already in Phoenix — prompt versions, experiment results, datasets, evaluations, annotations, and trace data — and its capabilities adapt to the page you are on. What it can do on a trace differs from what it can do in the prompt playground.

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Skills

A skill is a reusable, multi-step procedure for one Phoenix workflow — what to look at, in what order, and what the output should be. PXI loads the matching skill on demand rather than improvising each investigation from scratch. The library is under active development and grows each release — track progress on the Phoenix roadmap milestone.

Trace debugging

Walk failing traces against a failure-mode checklist for prioritized root-cause hypotheses. Available today.

Prompt playground

Co-author and optimize prompts, with every edit shown as a diff to approve. Available today.

Span annotation

Annotate spans and apply labels in bulk across a trace or project. Available today.

Evaluator authoring

Draft and refine LLM-as-a-judge evaluators against your data. Available today.

Dataset curation

Turn the failures you find into curated datasets for experiments and evals. Under development.
Because skills are context-aware, PXI surfaces the right one for the page and task you are on.

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You stay in control

Agent assistance is opt-in. PXI can be turned off completely, runs under an explicit permission model, and only reaches the internet when you let it.
PXI assistant settings
  • Turn it fully off. Disable PXI per deployment (PHOENIX_DISABLE_AGENT_ASSISTANT=true), per instance (Settings → Assistant → System settings), or per browser (Settings → Assistant → Personal settings → Use assistant).
  • Nothing changes without your approval. Any state-changing action — editing a prompt, saving a prompt, annotating spans — is gated by an edit-approval mode you pick from the chat input (or cycle with Ctrl+T). Read-only actions run freely.
  • Add web grounding when you want it. Toggle web access with the globe button in the chat input to let PXI consult the live internet for additional grounding. The toggle is per session and only appears when an administrator allows it; leave it off to keep the session entirely inside your Phoenix instance.
Edit-approval modeBehavior
Manual Approval (default)PXI proposes the change as a reviewable diff and waits. Nothing is applied until you click Accept.
Bypass ApprovalEdits are applied without asking. The selector shows a warning treatment while active.

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Setup

Configure credentials for at least one provider via environment variables or Phoenix secrets (OPENAI_API_KEY, ANTHROPIC_API_KEY, GEMINI_API_KEY, AWS Bedrock credentials, or a custom provider under Settings → Models). The consent gate shown the first time you open PXI enables the chat surface for that browser; it does not override system settings. PXI relies heavily on tool calling — almost every action it takes is a tool call. Models that are weak at tool use produce broken sessions even if they handle free-form chat well. Pick one of these validated models unless you have a specific reason not to:
  • Anthropic — claude-opus-4-8, claude-opus-4-6, claude-sonnet-4-6
  • OpenAI — gpt-5.5, gpt-5.4, gpt-5.4-mini
  • Google — gemini-3.1-pro-preview, gemini-3.5-flash
Other built-in or custom-provider models can be selected from the model menu, but they are untested with PXI and may fail to invoke tools correctly.

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How it works

PXI is split between the Phoenix server, which owns everything the model sees (tool definitions, system prompt, skills, capability guidance), and the browser, which executes tool calls that touch the page. Capabilities are gated by context — PXI only advertises a tool when the required Phoenix UI context is present, so it does not offer an action that cannot succeed on your current page.
The browser owns the chat UI and a sandboxed bash environment. Inside it, PXI uses the phoenix-gql CLI to query the Phoenix GraphQL API — the same authenticated endpoint a logged-in user hits. The server hosts the agent and its model-facing surface (tools, skills, an MCP client) and calls your LLM provider with your API key. When external resources are allowed, the server also reaches the Mintlify-hosted Phoenix docs MCP.
PXI runs inside the Phoenix process you are already running:
  • Tool calls execute against your Phoenix server and your data — no separate Arize service is involved.
  • The LLM is your model provider, called with your API key. Arize is not in the request path.
  • Documentation lookups go to the Mintlify-hosted Phoenix docs MCP server when external resources are allowed — the same public docs you can read in a browser, serving docs only.
  • Remote trace export happens only if every gate is enabled: a remote collector is configured, an administrator allows export in system settings, and the user enables it in personal settings.

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Privacy, safety & configuration

PXI can capture conversations as Phoenix traces, controlled by both system settings and per-browser preferences. From Settings → Assistant, administrators can turn assistant access on or off for everyone, allow users to save session traces locally, and allow export to a configured remote collector; each user can show or hide the assistant and opt into local or remote trace recording when allowed.By default the system settings allow neither local persistence nor remote export. Local traces are written to the assistant_agent project (override with PHOENIX_AGENTS_ASSISTANT_PROJECT_NAME). When recording is enabled, tool inputs and outputs are recorded on the corresponding spans, so you can audit what PXI did and evaluate it like any other agent in Phoenix.
  • Verify before you act. PXI can apply filters, edit prompts, and run bash. Review proposed changes — especially prompt edits — before accepting.
  • Don’t point it at sensitive production data without controls. PXI sees whatever the signed-in user can see.
  • Treat outputs as suggestions. PXI hallucinates, especially on long traces or unfamiliar frameworks.
Environment variableEffect
PHOENIX_DISABLE_AGENT_ASSISTANT=trueDisable PXI for the whole deployment (requires restart).
PHOENIX_ALLOW_EXTERNAL_RESOURCES=falseDisable external resource access, including the Phoenix docs MCP lookups.
PHOENIX_AGENTS_DISABLE_WEB_ACCESS=trueDisable PXI’s web search/fetch tools while leaving other external resources available.
PHOENIX_AGENTS_COLLECTOR_ENDPOINTRemote collector endpoint for assistant trace export.
PHOENIX_AGENTS_COLLECTOR_API_KEYAPI key for the remote collector, if required.
PHOENIX_AGENTS_ASSISTANT_PROJECT_NAMEProject name for locally recorded assistant traces (default assistant_agent).

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Feedback

PXI is in beta and will make mistakes. If you hit a rough edge or want to suggest new capabilities, open an issue or start a discussion on GitHub.