epic: JMESPath — jpx-engine migration, query files, introspection

[joshrotenberg]

Overview

Overhaul the JMESPath subsystem in redisctl. The current setup (jmespath + jmespath_extensions crates) is outdated. jpx-engine provides 400+ functions, better error messages, and is the same engine powering the jpx CLI and MCP server. This is a full rethink, not an incremental patch.

Goals

• Migrate to jpx-engine as the JMESPath backend
• Ship pre-built query files for common analysis patterns (cost reports, resource inventory)
• Add query introspection commands for discoverability
• Consistent JMESPath experience across CLI, MCP server, and jpx tools

Sub-Issues

Core Migration

• Evaluate jpx-engine as JMESPath backend #594 -- Evaluate jpx-engine as JMESPath backend (scope: replace jmespath + jmespath_extensions with jpx-engine)

Query Files

• Support @file syntax for JMESPath queries #593 -- Support @file syntax for JMESPath queries
• Ship pre-built FOCUS queries for cost-report analysis (top-N resources, cost-by-region, cost-by-charge-category, etc.)
• Named query store (define, run, list) -- enabled by jpx-engine's query store API

Introspection

• redisctl jmespath functions -- list available functions by category
• redisctl jmespath describe <fn> -- show function signature, description, examples
• redisctl jmespath search <keyword> -- fuzzy search for functions

Integration

• Audit all commands that accept -q / --query and ensure consistent behavior
• Better error messages for invalid expressions (jpx-engine provides source spans)
• Consider MCP tool for JMESPath evaluation (would let agents query/transform data in-context)

Key Paths

• Current JMESPath usage: Cargo.toml dependencies on jmespath + jmespath_extensions
• jpx-engine: https://joshrotenberg.com/jmespath-extensions/libraries/jpx-engine.html
• jpx MCP server: already in use as an MCP tool in this project's dev setup

References

• Evaluate jpx-engine as JMESPath backend #594 -- jpx-engine evaluation
• Support @file syntax for JMESPath queries #593 -- @file query syntax
• jpx-engine docs: https://joshrotenberg.com/jmespath-extensions/libraries/jpx-engine.html