MCPg v0.6.7 — release notes

Released: 2026-07-03 Tool surface: 252 tools across 19 capability buckets Tests: 2741 pass (PG 14 / 15 / 16 / 17 / 18 / 19 / WarehousePG) Runtime: Python 3.14

This is a patch-level bump (0.6.6 → 0.6.7) focused on the client experience: the safety classification now reaches the wire, a curated demo dataset gives new users a rich first five minutes, and the runtime moves to Python 3.14. No tool signatures changed; everything is backward-compatible.

Headline: MCPg’s safety model is now on the wire

Every one of the 252 tools now publishes MCP ToolAnnotations:

• readOnlyHint — true for the 185 read tools, false for the 67 write-capable ones. Derived mechanically from the same READ / WRITE / DDL / SHELL / LISTEN capability gates that enforce access, so a tool moved between gates can never ship a stale hint. A contract test pins the derivation exhaustively: the hinted read-only set must equal the tool surface actually reachable in read-only access mode.
• openWorldHint — false everywhere except translate_nl_to_sql (the one tool that calls an external LLM API); everything else talks only to the connected PostgreSQL server.
• destructiveHint is deliberately left unset for write-capable tools: the MCP default (true) is the cautious reading.

Clients like Claude Desktop use these hints to decide which calls to auto-approve — until now MCPg’s “safe by default” story was internal; now it’s visible to every MCP client. The 3 MCP prompts’ arguments all carry wire-visible descriptions too.

Try MCPg in two minutes: the demo dataset

MCPG_DATABASE_URL=postgresql://... mcpg --demo       # seed
MCPG_DATABASE_URL=postgresql://... mcpg --demo-drop  # remove

mcpg --demo seeds a small, deterministic, curated e-commerce dataset (400 customers, 120 products, 3,000 orders, 900 reviews) into an mcpg_demo schema — engineered so the pivotal tools all have something real to find on first contact: an un-indexed foreign key for analyze_query_plan / recommend_indexes, PII-shaped columns for find_sensitive_columns, a camelCase naming violation, searchable review prose, and an optional pgvector embedding column when the extension is installed. The seed is a single transaction, re-seeding refuses rather than clobbers, and --demo-drop only removes a schema carrying the MCPg ownership marker.

The companion guided tour is captured, not written — every output block is a real tool run against the seeded dataset, and integration tests pin the planted findings so the walkthrough can’t silently rot.

Also in this release

• Runtime moves to Python 3.14 — Docker image, the full CI matrix, and the publish pipeline. requires-python stays >=3.12; installing on 3.12/3.13 is unchanged.
• Startup warning noise eliminated — the benign pydantic “Field name schema shadows an attribute in parent BaseModel” warnings on first tools/list are suppressed (narrowly, by message pattern), with a contract test guarding the full tool surface.
• Release-pipeline hardening — the TestPyPI smoke test now polls the PEP 503 simple index (what pip install actually reads) instead of the JSON API, eliminating the propagation race that required a manual re-run during the v0.6.6 release.

Upgrade

pip install --upgrade mcpg
docker pull ghcr.io/devopam/mcpg:0.6.7   # or :latest

No configuration changes required.

Full changelog

See ../CHANGELOG.md [0.6.7] for the complete itemised list.