jcl-crawler

Extract mainframe source inventories and JCL job chains from z/OS source drops.

1|1|Updated Apr 6, 2026
One-click install
npx skills add https://github.com/duboc/mainframe-skills-mig --skill jcl-crawler
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: jcl-crawler
Source: https://github.com/duboc/mainframe-skills-mig/tree/main/skills/01-jcl-crawler
Command: npx skills add https://github.com/duboc/mainframe-skills-mig --skill jcl-crawler

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Create a complete, auditable inventory of mainframe source artifacts and their runtime relationships to eliminate surprises during migration and enable downstream translation, testing, and cutover planning.

Core Features & Use Cases

  • JCL Parsing & Job Chain Mapping: Extract job names, steps, DD datasets, and produce a job chain dependency diagram to reveal producer/consumer relationships.
  • COBOL Program Inventory & Copybook Expansion: Discover PROGRAM-ID, COPY references, CALL targets, COMP-3 fields, and produce program inventory in JSON/CSV for traceability.
  • BMS Screen & Call Graph Extraction: Parse BMS mapsets into structured screen definitions and build an inter-program call graph to identify tightly coupled clusters for service boundary decisions.
  • Operational Safety & Blocker Detection: Detect EBCDIC encoding, flag missing copybooks, and enforce blocker thresholds before marking Phase 01 complete.

Quick Start

Run the jcl-crawler on your source drop to generate the JCL inventory, program inventory, comp3 registry, BMS screens, job chain diagram, and call graph for Phase 01.

Frequently Asked Questions about jcl-crawler

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I extract a complete inventory of COBOL programs and JCL job chains for mainframe migration?▼

To extract a mainframe inventory, parse z/OS source drops containing COBOL, JCL, and copybooks. This generates structured artifacts like program_inventory.json and jcl_inventory.json, mapping job chains and program relationships for migration planning.

How does COMP-3 detection work during COBOL copybook expansion?▼

COMP-3 detection works by parsing COBOL source and expanding copybooks to identify computational-3 packed decimal fields. It registers these fields in a comp3_registry.json file, ensuring traceability of packed decimal data structures during migration analysis.

Can I build an inter-program call graph from BMS mapsets and COBOL source?▼

Yes, you can build an inter-program call graph by parsing BMS mapsets into structured screen definitions and extracting CALL targets from COBOL programs. This identifies tightly coupled clusters to inform service boundary decisions.

How do I map JCL job chain dependencies and producer/consumer relationships?▼

Map JCL job chain dependencies by parsing job names, execution steps, and DD datasets. This produces a job_chain.mmd diagram revealing producer and consumer relationships across runtime jobs, clarifying batch processing workflows.

What blockers are detected when parsing EBCDIC encoded mainframe source artifacts?▼

Parsing EBCDIC encoded mainframe source artifacts detects blockers like missing copybooks and encoding errors. The process enforces blocker thresholds before marking Phase 01 complete, ensuring operational safety.