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AGENTS.md — PostHog Wizard

Instructions for all agents (and humans) working in this repo. This is the single source of truth; CLAUDE.md just points here. User-facing docs: https://posthog.com/docs/ai-engineering/ai-wizard

The PostHog wizard (npx @posthog/wizard) is a CLI that adds PostHog to a user's project using an AI agent. It authenticates the user, detects their framework, runs an agent that integrates the SDK and instruments events, and walks the user through their first dashboard. All from the terminal.

Design discipline

This codebase follows a specific design discipline: product knowledge never enters infrastructure code. The runner pipeline, the TUI store, the detection loop, and the prompt assembler are machinery. They don't know what PostHog is. They don't know what a framework is. They execute a pipeline driven by typed configuration surfaces.

Each domain has a dedicated boundary:

  • Frameworks → FrameworkConfig in src/programs/frameworks/<name>/
  • Integration knowledge → markdown skills in the context-mill repo
  • Security policy → YARA-X rules in the warlock sibling repo. The wizard wires the scanner through SDK hooks and Pi tool events; see security boundaries. Gateway admission and required safety prompts live in ai-gateway. To disable scanning in the field without a release, see the kill-switch runbook: docs/runbooks/warlock-kill-switch.md. ONLY USE THIS IF ABSOLUTELY NECESSARY.
  • Agent → src/agent/, imported only through @agent (values) and @agent/types (types); see src/agent/README.md
  • Shared → src/shared/, stateless library code with no upward imports; see src/shared/README.md
  • Programs → program configs and runProgram in src/programs/; see src/programs/README.md and the developer interfaces
  • TUI → screens, primitives and content decks in src/ui/tui/

Adding a new concern means finding the narrowest existing surface, not adding logic to the runner. Keep changes local to the boundary that owns them.

Before making structural changes

Read wizard-development first. It covers the design discipline, a decision framework for new extensions, and warning signs that a change is drifting off-pattern. Its references extend it:

Skills available

Five skills live under .claude/skills/. Read wizard-development first for any structural change; then load the relevant procedural skill:

Skill When to use
wizard-development Before any structural change. Design principles + decision framework.
adding-framework-support Adding or extending a framework integration.
adding-skill-program Adding a new skill-based program (e.g. a new product feature setup).
ink-tui Building or modifying TUI screens, layouts, and primitives.
exploring-the-wizard Running/driving/exploring the wizard headlessly (read_state/perform_action, TUI snapshots).

Agent execution policy

Default new work to Pi, and prefer the orchestrator sequence. Linear execution remains useful for very simple tasks and legacy support. The Anthropic Agent SDK is a supported legacy fallback, deprecated as the default; retain it for major Pi vulnerabilities or gaps in support for new Anthropic models.

This is the contribution policy, not a claim that every existing binding has migrated: DEFAULT_BINDING is Pi + linear. Set new bindings explicitly and check sequence-specific hooks before migrating existing flows. See execution policy and model admission for the gateway allowlists, required system prompt, and composition constraints.

CLI command surface

The CLI was overhauled to a smaller, extensible command surface. Use the new command names. Old names mostly no longer exist — only some are kept as aliases.

Old command New command Status
wizard integrate wizard (default flow) command removed
wizard events-audit wizard audit events moved into audit family
wizard audit (single) wizard audit <subcommand> now a family — see Audit subcommands
wizard audit-3000 removed retired
wizard revenue wizard revenue-analytics renamed (old revenue removed)
wizard upload-sourcemaps wizard upload-source-maps renamed; upload-sourcemaps kept as alias

Audit subcommands

audit is the only family with skill-backed subcommands today:

Subcommand What it audits
wizard audit events event capture quality + cost
wizard audit all comprehensive audit across every area (default)
wizard audit autocapture autocapture setup + cost
wizard audit feature-flags feature flag usage + cost
wizard audit identify $identify implementation
wizard audit session-replay session replay setup
wizard audit web-analytics web analytics setup (wizard-native, not a skill)

Commands vs. skills (the audit [skill] gotcha)

A skill and a command are the same machinery — a context-mill skill becomes a command when its cli: block sets role: command. So wizard audit events is the audit-events skill, just promoted. wizard skill <skill-name> (skill.ts) runs a skill that wasn't promoted.

Two surfaces, one mechanism. So wizard audit <subcommand> is choosing an audit area — it is not asking for a skill name, despite wizard audit --help labelling the positional [skill] (a wizard-internal name we left as-is). Don't confuse it with the top-level wizard skill command.

Where the surface is defined (source of truth)

Commands vs. programs (don't confuse these)

  • A command is the word a user types (audit, revenue-analytics).
  • A program is the internal business logic (posthog-integration, revenue-analytics-setup) that a command invokes, and that other programs depend on via requires: [...].
  • posthog-integration is a program id, not a command. It powers the default flow and is a dependency of most other programs. Do not treat it as a CLI command or reference it in CI as one.

Adding a command alias (keep an old name working)

Give the Command.name an array of [newName, ...legacyNames]. yargs treats the extra entries as aliases. See src/commands/upload-sourcemaps.ts. Reserve aliases for names that external callers (users' scripts) may still use — when the only caller is one we control, update the caller instead.

Commands

pnpm install                       # Install dependencies
pnpm try --install-dir=<path>      # Run the wizard locally against a test project
pnpm build                         # Compile TypeScript
pnpm test                          # Unit tests (builds first)
pnpm test:watch                    # Unit tests in watch mode
pnpm test:e2e                      # End-to-end tests
pnpm lint                          # Prettier + ESLint checks
pnpm fix                           # Auto-fix lint issues
pnpm dev                           # Build, link globally, watch for changes

Choose verification for the change: check links and formatting for docs; run pnpm typecheck and focused existing tests for code. Build when bundling or runtime behavior changes. pnpm test already builds; avoid building twice. Use nonmutating lint checks, and scope formatting fixes to edited files. Do not add tests for prose, compiler-enforced shapes, or duplicated implementation. Keep new code comments to one line; put longer explanations in linked docs.

Local --ci, smoke-test, and full headless runs require two separate secrets: a PostHog personal API key and an already-issued gateway token supplied through WIZARD_CI_GATEWAY_TOKEN_FILE, plus the target project ID. Follow the credential setup.

Local dev targets

Four things can independently point at a local server — the wizard binary, context-mill (:8765), the MCP server (:8787), and PostHog (:8010). One flag per service (--local-context-mill, --local-mcp, --local-posthog), plus --local-dev for all three. They're dev-build-only; published builds reject them.

Note wizard mcp add --local is not one of these — it writes a posthog-local entry into your editor's MCP config, and is unrelated to where a wizard run points. Full catalog: docs/local-dev.md.

Repository conventions

  • Write documentation as the current design. Describe behavior and usage directly; omit change history, migration narration, and implementation rationale. Apply the same style to PR descriptions.

  • TypeScript everywhere. Use type (not interface) for framework context types so they satisfy Record<string, unknown>.

  • All UI calls go through getUI() (returns WizardUI interface). Never import the store directly from business logic. A program's run and ciPreRun use the runner context they receive, not getUI().

  • Shared helpers never call getUI(); they take a sink or return data. debug() reaches the UI through the sink src/ui/index.ts installs.

  • Outside src/agent, import the agent through @agent or @agent/types. Add to those entry modules rather than deep-importing; lint and pnpm test:arch reject @agent/* paths elsewhere.

  • Session mutations go through explicit store setters that call emitChange(). Never mutate session directly — nanostore holds a shallow copy.

  • The router resolves the active screen from session state. No imperative navigation (goTo, navigate, push) anywhere.

  • Never write secrets to source code or hardcode API keys. Use the wizard-tools MCP server (check_env_keys / set_env_values) for .env file operations.

  • Feedback / issues: wizard@posthog.com or GitHub Issues.

Companion projects

  • context-mill — builds and publishes the markdown skills the wizard agent uses for framework-specific integration knowledge. Skills are decoupled from the wizard release cycle so docs and integration patterns can update independently.
  • wizard-workbench — the development and testing environment. Houses framework test apps (Next.js, React Router, Django, Flask, Laravel, SvelteKit, Swift, TanStack, FastAPI) with no PostHog installed, plus an mprocs-driven local dev stack that runs context-mill + MCP + the wizard together with hot reload. Use this to develop and test wizard changes against real projects.
  • warlock — the security scanner engine for PostHog's agentic flows. Bundles YARA-X rules for prompt injection, exfiltration, destructive operations, supply chain attacks, hardcoded secrets, and PII. Engine-only: it returns matches with category/severity/action metadata; the wizard decides how to respond. New security rules belong in warlock, not in the wizard.