Orchestrator

The core loop in src/psi/orchestrator.py. Runs sequential phases, each as a series of Claude Code subprocess calls.

Overview

Psi class coordinates everything:

• •Validates project files exist (CLAUDE.md, PRD.md, development-progress.yaml, phase-1.md)
• •Iterates phases from development-progress.yaml
• •Each iteration: builds prompt, calls claude -p via stdin, parses output for signals
• •Between phases: runs Tier 2 skill sync, generates next phase prompt

Key Patterns

Subprocess Invocation

Prompts are passed via stdin, not as CLI args (avoids OS arg length limits):

result = subprocess.run(
    ["claude", "-p",
     "--allowedTools", "Bash,Read,Write,Edit,Glob,Grep,WebFetch,WebSearch,mcp__context7__resolve-library-id,mcp__context7__query-docs"],
    input=prompt,          # stdin, not positional arg
    capture_output=True,
    text=True,
    timeout=self.timeout,
    cwd=str(self.project_root),
)

Documentation-First for Integrations

Prompt instructs Claude to search for docs before implementing any integration:

• •WebSearch for general doc discovery
• •mcp__context7__resolve-library-id + mcp__context7__query-docs for library-specific docs
• •Never guess API signatures — verify first

Signal Detection

Two signals parsed from Claude's stdout:

• •<promise>PHASE N COMPLETE</promise> — phase done, trigger Tier 2 sync
• •<phase-blocked>N</phase-blocked> — phase blocked, stop and report

YAML Read/Write (PyYAML)

Always use safe variants per PyYAML docs:

• •yaml.safe_load() for reading (prevents arbitrary object construction)
• •yaml.safe_dump() for writing (restricts output to safe types)
• •default_flow_style=False for block-style output
• •sort_keys=False to preserve insertion order

PhaseManager re-reads from disk every call (no caching) since Claude modifies the file externally.

Prompt Composition Per Iteration

Each iteration gets a freshly augmented prompt:

base_prompt (from phase-N.md or generated)
+ Tier 2 expertise patterns (top 20, high confidence first)
+ Tier 1 learnings (last 20, unvalidated)

Docker Pitfalls

• •environment: in docker-compose overrides env_file — don't duplicate vars in both
• •Web subprocess needs --allowedTools — Claude asks permission without it
• •Prompts need explicit autonomy instruction — Claude defaults to asking confirmation
• •MCP tools don't work in Docker — only built-in tools available
• •Initialize LEARNINGS.md before iteration loop in web flow
• •SQLite needs WAL mode + busy_timeout for multi-process writes

State Persistence

.psi/state.json tracks current phase/iteration. .psi/logs/phase_X_iter_Y.json stores per-iteration results with output preview and stderr.

Phase Lifecycle

1. •set_status(N, "in-progress") — update YAML via yaml.safe_dump()
2. •Loop iterations until signal or max reached
3. •If complete: run skill sync, set_status(N, "complete"), generate next prompt
4. •If blocked or max reached: stop loop

Related Files

• •src/psi/orchestrator.py — Psi class
• •src/psi/phase_manager.py — YAML state transitions (yaml.safe_load/yaml.safe_dump)
• •src/psi/prompt_generator.py — Prompt building + learning injection
• •src/psi/weave_logger.py — Observability tracing