Implementation blueprint from spike experiments — SEP-2640 Skills support AND the schema-server toolkit lift (config-driven MCP servers for SQL / GraphQL / OpenAPI backends). Requirements, proven patterns, multi-dialect SQL connector trait, two-axis Skills (Type 1 build-time vs Type 2 runtime SEP-2640), and the dual-surface invariant. Auto-loaded during implementation work.
Help a developer design a config.toml for a PMCP schema-server toolkit deployment, applying the Pareto principle to curated tools and code-mode policy.
Demonstrates the simplest possible MCP skill
Process customer refund requests per company policy
| name | code-mode |
| description | Generate validated GraphQL queries against this server's schema |
This server exposes validate_code and execute_code tools for running
LLM-generated GraphQL queries with cryptographically signed approval tokens.
skill://code-mode/references/schema.graphql for available types.skill://code-mode/references/examples.md for canonical patterns.skill://code-mode/references/policies.md for what's allowed.validate_code(code: "<your query>"). You'll get back an
approval_token plus a human-readable explanation. Show the explanation
to the user.execute_code(code, token). Any modification
to code between validate and execute invalidates the token.For simple lookups that match a curated tool (e.g. get_user_by_id),
prefer that tool. Code mode is for the long tail of compositions that
don't have dedicated tools.