Attribute CLI telemetry to Claude Code and Codex command trees

[andrelandgraf]

Problem

Telemetry cannot tell a neon run started by a coding agent from one a person typed. Agents drive the CLI through a shell they own, so the process the agent launches is often a wrapper and the CLI turns up several levels down the tree. Checking the immediate caller answers the wrong question.

What decides attribution

getCliAgent(env) in packages/cli/src/env.ts reads the environment a launched command tree inherits, so it identifies a neon process anywhere under a Claude Code or Codex launch rather than only a direct child.

Session	Required
Claude Code	CLAUDE_CODE_CHILD_SESSION=1
Codex	CODEX_CI=1 and a non-empty CODEX_THREAD_ID or CODEX_SESSION_ID

Codex ids on their own mark a command the user typed in the Codex shell, so those runs stay unattributed. CLAUDECODE, CLAUDE_CODE, CLAUDE_CLI, CODEX, CODEX_SANDBOX and CODEX_SANDBOX_NETWORK_DISABLED are ambient or sandbox utility markers and never attribute on their own. When a Claude session and a Codex session both look active, the markers are nested and the property is omitted.

The property

agent rides on CLI Started, cli_command_success and CLI Error.

Claude Code:

{ "command": "branches list", "ci": false, "agent": "claude-code" }

Codex:

{ "command": "branches list", "ci": false, "agent": "codex" }

Unattributed:

{ "command": "branches list", "ci": false }

Three outcomes: claude-code, codex, or the property absent. Absent covers the human case and the conflicting-marker case.

How the CLI is invoked and what it prints are unchanged, and neon init behaves the same. No changeset: nothing a package consumer can call or see moved.

Also in here

src/init/agent_snapshot.test.ts and src/init/auth.test.ts spawn the real built CLI. Both set NEON_NO_ANALYTICS=1, which is read nowhere in the repo, so those runs were live. Both now pass --no-analytics, the flag the CLI honors.

src/analytics.test.ts clears CODEX_CI, CODEX_THREAD_ID and CODEX_SESSION_ID before asserting the Claude Code case, and unstubs env after each test. Run the suite inside a Codex session and the inherited markers would otherwise make it a conflict and omit the property.

Verification

• pnpm --filter neon test - 4470 passed, 6 skipped; 168 files passed, 3 skipped
• pnpm lint:ci - clean
• CODEX_CI=1 CODEX_THREAD_ID=review-repro pnpm --filter neon exec vitest run src/analytics.test.ts - 17 passed, which is the isolation the plain run cannot catch

Cases covered: Claude child session; Codex thread id; Codex session id; Codex ids with no CODEX_CI; CLAUDE_CODE_CHILD_SESSION=false with whitespace-only ids; the ambient and sandbox marker set; a Claude-inside-Codex conflict; agent present on the error event context.

Not verified: no event was sent to a live endpoint. Assertions sit at the property builders rather than at the wire.

For your attention

• Downstream ingestion does not read agent yet. Events carry it from the next release and it stays invisible in reporting until ingestion is updated.
• The contract is environment markers, so it detects what each tool sets today. A release of either tool that renames or drops a marker returns those runs to the unattributed case with no failure.