pse-edge-mcp: Instructions file for Claude Code

CLAUDE.md

MCP server exposing Philippine Stock Exchange (PSE Edge, https://edge.pse.com.ph) data. Unofficial — Edge has no public API; we speak to the portal's own internal endpoints.

Read these first — they are the project's memory:

• docs/plan.md — every design decision: scope, architecture, caching policy, auth design, delivery history, risks. Treat decided items as settled unless the user says otherwise.
• docs/endpoints.md — the verified endpoint map: request dialects, param names, response shapes, pagination. Trust this over guesses.

This file holds only what applies to every task. Task-specific rules (caching mechanics, auth invariants, release procedure, deploy/debug, subsystem gotchas) live in the agent memory index — load the matching topic file before working in that area.

Memory write rule: when recording a new durable instruction ("remember that…", a correction, a learned fact), create or edit the one single-purpose topic file it belongs to under the memory directory and update its line in the index. Never append to this file without asking — it is always loaded, and unchecked additions re-monolithize it.

Non-negotiable invariants

1. Never refetch a cached price while the market is open (09:30–15:00 Asia/Manila, trading days). Every upstream read goes through FreezeService.get(..., policy=...) — never call PseEdgeClient directly from a tool. The default policy is the strictest, so an unlabelled read can only over-protect PSE Edge.
2. Tests never touch PSE Edge. All HTTP is mocked with respx against fixtures in tests/fixtures/ (recorded from real captures). A new endpoint needs a new fixture.
3. Loud on drift. If Edge's response shape changes, raise EndpointChangedError — never silently return partial data.
4. No credentials anywhere: not in commits, image layers, ARGs, or ENV.

Architecture

server.py        MCP boundary only: validate args, delegate, shape the reply.
  ↓
repositories.py  One repository per data domain: cache key + freeze read + parse +
                 model. Endpoint routing lives here.
  ↓
service.py       Freeze policy. Repositories depend on the FrozenCache protocol and
sources.py       the narrow per-domain source protocols — never the concrete client.
  ↓
client.py        Pure HTTP.  parsers.py  HTML/JSON → dicts.