Phoenix phoenix-cli-development

install

source · Clone the upstream repo

git clone https://github.com/Arize-ai/phoenix

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/Arize-ai/phoenix "$T" && mkdir -p ~/.claude/skills && cp -r "$T/js/packages/phoenix-cli/.agents/skills/phoenix-cli-development" ~/.claude/skills/arize-ai-phoenix-phoenix-cli-development && rm -rf "$T"

manifest: js/packages/phoenix-cli/.agents/skills/phoenix-cli-development/SKILL.md

source content

Phoenix CLI Design Specification

The Phoenix CLI (

px

) is a command-line interface for the Phoenix AI observability platform. It serves two distinct audiences simultaneously: humans typing commands in a terminal and coding agents (Claude Code, Cursor, Codex, Gemini CLI) executing commands programmatically.

This specification uses RFC 2119 keywords (MUST, SHOULD, MAY, etc.) to indicate requirement strength.

Command Structure: Noun-Verb

All commands MUST follow a noun-verb pattern, modeled after the GitHub CLI (

gh

px <resource> <action> [arguments] [options]

Resource names MUST be singular — they name the type of thing you're acting on, not how many:

px project list              # not "px projects"
px project create            # not "px create-project"
px trace get <trace-id>
px dataset get <name-or-id>
px auth status

Standard verbs

Commands SHOULD use these verbs consistently across all resources:

Verb	Purpose	Takes argument?	Example
`list`	List/query multiple resources	No (uses flags)	`px project list --limit 10`
`get`	Fetch a single resource by ID	Yes (required)	`px trace get <trace-id>`
`create`	Create a new resource	Varies	`px project create --name foo`
`update`	Modify an existing resource	Yes (required)	`px project update <id> --name bar`
`delete`	Remove a resource	Yes (required)	`px project delete <id>`

Not every resource supports every verb — datasets MAY omit

create

via CLI if the primary flow is through the SDK. Commands SHALL only add verbs that make sense for the resource.

Additional verbs for specialized actions are RECOMMENDED when the standard set doesn't cover it:

```
px auth login
```
,
```
px auth status
```
```
px self update
```
```
px docs fetch
```
```
px api graphql <query>
```

Backward compatibility during migration

The CLI is evolving from a flat structure (

px projects

px traces

) toward full noun-verb. During the transition, both forms MAY coexist. When migrating an existing command:

The new noun-verb form MUST be created as the primary command
The old form SHOULD be kept as a hidden alias (Commander's
```
.alias()
```
or a hidden command) so existing scripts don't break
Only the noun-verb form SHALL be documented going forward

Dual-Audience Design

The CLI MUST be equally usable by a person at a terminal and by a coding agent. Every command that outputs data MUST support

--format

pretty
(default) — Human-readable tables and formatting
json
— Indented JSON for human inspection of structured data
raw
— Compact single-line JSON for piping into
```
jq
```
or agent consumption

Commands MAY support additional formats (e.g.,

--format text

for prompts). The default MUST always be

pretty

Progress indicators MUST write to stderr. Agents SHOULD pass

--no-progress

to suppress them.

# Agent-friendly invocation
px trace list --format raw --no-progress | jq '...'

Semantic exit codes

Defined in

src/exitCodes.ts

. Commands MUST use the named constants and MUST NOT use bare numeric literals.


SUCCESS
FAILURE
CANCELLED
INVALID_ARGUMENT
AUTH_REQUIRED
NETWORK_ERROR

Interactive default with non-interactive mode

Commands MAY prompt interactively when a required value is missing or a confirmation is needed — this is the human-friendly default. The

--no-input

flag MUST suppress all prompts: both missing-value prompts and destructive-action confirmations. Non-interactive mode is also activated automatically when no TTY is attached (piped stdin).

In non-interactive mode, if a required value is missing, the command MUST exit immediately with

ExitCode.INVALID_ARGUMENT

and print the correct invocation. If a confirmation would have been shown, the command MUST proceed as if confirmed:

# Human: missing --name triggers interactive prompt
px project create

# Agent: all inputs as flags, no prompts
px project create --name my-project --format raw --no-input

# Human: gets "Are you sure?" prompt
px dataset delete my-dataset

# Agent: skips confirmation
px dataset delete my-dataset --no-input --format raw

Error: Missing required flag --name.
  px project create --name <project-name>

Idempotent commands

Commands SHOULD be idempotent where possible. Running the same command twice MUST NOT produce duplicate resources or unexpected errors:

```
create
```
commands SHOULD support
```
--if-not-exists
```
to return the existing resource instead of failing
```
delete
```
commands on a missing resource SHOULD exit with
```
ExitCode.SUCCESS
```
(not an error)

Return structured data on success

Mutating commands (

create

update

delete

) MUST return the affected resource in the selected

--format

on stdout. Commands MUST NOT print bare success messages like "Project created." — output the resource so agents can extract IDs, URLs, and other fields:

$ px project create --name foo --format raw
{"id":"proj_abc","name":"foo","createdAt":"2025-03-15T10:00:00Z"}

Fail fast with actionable errors

When a command fails due to invalid input, the error message MUST include the correct invocation syntax. Follow the pattern established by

getConfigErrorMessage()

src/config.ts

Show what was wrong
Show the correct command to fix it
Suggest a related command when helpful (e.g., "Available projects:
```
px project list
```
")

When

--format raw

--format json

is active, errors SHOULD also be written as structured JSON to stderr so agents can parse them. Use the

StructuredError

shape:

interface StructuredError {
  error: string; // Human-readable error message
  code: string; // ExitCode constant name (e.g., "INVALID_ARGUMENT")
  hint?: string; // Suggested command to resolve the issue
}

{
  "error": "Project not found",
  "code": "FAILURE",
  "hint": "px project list --format raw"
}

Progressive help discovery

Every subcommand MUST include a

--help

with at least one concrete example. Use Commander's

.addHelpText('after', ...)

to append an

Examples:

block:

$ px project create --help
Usage: px project create [options]

Create a new Phoenix project.

Options:
  --name <name>       Project name (required)
  --description <d>   Project description
  --format <format>   Output format (pretty|json|raw) (default: "pretty")
  -h, --help          Display help

Examples:
  px project create --name my-project
  px project create --name my-project --format raw

Agents discover capabilities incrementally:

px

→

px project

→

px project create --help

. Each level MUST provide enough information to navigate deeper.

Adding a New Command

Options interface

Every handler MUST define a TypeScript interface for its options. Field names MUST be descriptive — abbreviations MUST NOT be used. Common options that appear across many commands:

interface CommonOptions {
  endpoint?: string; // --endpoint: Phoenix API endpoint override
  apiKey?: string; // --api-key: API key override
  project?: string; // --project: Project name or ID override
  format?: OutputFormat; // --format: Output format (pretty/json/raw)
  progress?: boolean; // --no-progress: Suppress progress indicators
}

Commands that prompt for input or confirmation MUST support non-interactive mode:

interface InteractiveCommandOptions extends CommonOptions {
  noInput?: boolean; // --no-input: Suppress all prompts
}

Configuration resolution

The CLI MUST resolve configuration from multiple sources. Use

resolveConfig()

from

src/config.ts

for this merge logic. Priority:

CLI flags (highest priority) —
```
--endpoint
```
,
```
--api-key
```
,
```
--project
```

Environment variables —

PHOENIX_HOST

PHOENIX_API_KEY

PHOENIX_PROJECT

Defaults —
```
http://localhost:6006
```
for endpoint

Command handlers MUST NOT read environment variables directly.

Output formatting

Each resource type SHOULD have formatting modules in

src/commands/format*.ts

. When creating a new resource command, a corresponding formatter MUST be created following the existing pattern.

```
formatTable.ts
```
— Shared table rendering with terminal-width-aware column truncation

formatProjectsOutput()

formatTracesOutput()

, etc. — Resource-specific formatters

Formatters MUST accept a

format

option and return a string.

I/O functions

Commands MUST use the helpers from

src/io.ts

writeOutput({ message }); // → stdout (data the user/agent wants)
writeError({ message }); // → stderr (errors)
writeProgress({ message, noProgress }); // → stderr (suppressible status updates)

console.log

MUST NOT be used directly. The

writeOutput

writeError

split ensures stdout contains only data output, which is REQUIRED for piping correctness.

Naming Conventions

Code MUST follow these naming conventions (see also the phoenix-typescript skill):

Functions and variables:

camelCase

—

createProjectCommand

projectListHandler

Types and interfaces:

PascalCase

—

ProjectListOptions

OutputFormat

Constants:

SCREAMING_SNAKE_CASE

—

ExitCode.SUCCESS

CLI_VERSION

Files:

camelCase.ts

—

projects.ts

formatProjects.ts

No abbreviations —

projectIdentifier

not

projId

annotationConfig

not

annCfg

Testing

Tests use vitest and live in the

test/

directory, mirroring

src/

structure.

pnpm test          # run all tests
pnpm test:watch    # watch mode

When adding a command, tests MUST cover:

The handler logic (mocking the Phoenix client)
Formatter output for each format mode
Edge cases: missing config, network errors, empty results
Exit code correctness for error paths

Build and Run

pnpm build         # TypeScript → build/
pnpm dev           # Run from source via tsx (during development)

The CLI is published as

@arizeai/phoenix-cli

with binary aliases

px

and

phoenix-cli

Global Options Placement

Global options (

--endpoint

--api-key

) MUST be placed on the verb, not the noun. This is REQUIRED because Commander attaches options to the command that defines them:

# Correct — options on the verb
px project list --endpoint http://my-server:6006

# Wrong — options on the noun (Commander won't parse these)
px project --endpoint http://my-server:6006 list

Checklist for Adding a New Resource Command

Create

src/commands/<resource>.ts

with

create<Resource>Command()

exporting the noun

Add verb subcommands (
```
list
```
,
```
get
```
,
```
create
```
, etc.) as needed
Create
```
src/commands/format<Resource>.ts
```
for output formatting
Define options interfaces with descriptive field names
Use
```
resolveConfig()
```
for configuration,
```
createPhoenixClient()
```
for API calls
Use
```
writeOutput()
```
/
```
writeError()
```
for I/O, semantic
```
ExitCode
```
constants for errors
Export from
```
src/commands/index.ts
```
Register in
```
src/cli.ts
```
via
```
program.addCommand()
```
Add tests in
```
test/
```
Run
```
pnpm test
```
— fix any failures before proceeding
Run
```
pnpm build
```
— fix any type errors before proceeding
Update
```
README.md
```
with usage examples showing both human and agent-friendly invocations
Update the external Phoenix CLI skill at
```
.agents/skills/phoenix-cli/SKILL.md
```
when commands, flags, examples, or output shapes change
Keep skill updates concise: document the new capability with the smallest useful examples and output-shape notes rather than repeating the full README
If the command prompts for input or confirmation, support
```
--no-input
```
(see
```
InteractiveCommandOptions
```
)
Add at least one example to
```
--help
```
via
```
.addHelpText('after', ...)
```
Mutating commands return the affected resource on stdout (not just a success message)
Run manually with
```
--format raw
```
and
```
--no-input
```
to verify agents get clean, parseable output

Code	Constant	Meaning
0	`SUCCESS`	Command completed successfully
1	`FAILURE`	Unspecified or unexpected error
2	`CANCELLED`	User cancelled (e.g., declined a confirmation)
3	`INVALID_ARGUMENT`	Bad CLI flags, missing required args, invalid input
4	`AUTH_REQUIRED`	Not authenticated or insufficient permissions
5	`NETWORK_ERROR`	Failed to connect to server or network request