Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add OpenHands/extensions --skill to-java-migrationgit clone --depth 1 https://github.com/OpenHands/extensionsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/openhands/extensions/to-java-migration)<a href="https://agentmods.dev/skills/openhands/extensions/to-java-migration"><img src="https://agentmods.dev/badge/skills/openhands/extensions/to-java-migration/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/openhands/extensions/to-java-migration"><img src="https://agentmods.dev/badge/skills/openhands/extensions/to-java-migration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00031 | $0.00450 |
| Opus 5.5 | $0.00012 | $0.00180 |
| Sonnet 5.5 | $0.00006 | $0.00090 |
| Haiku 4.5 | $0.00003 | $0.00045 |
Grade A, and why
to-java-migration scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Migrate COBOL code to idiomatic Java, preserving all business logic.
Code Style Requirements
Write idiomatic Java, NOT literal COBOL translations:
- Use Java conventions: camelCase names, standard collections (List, Map)
- Use Java standard library instead of rolling your own
- No god classes — split into cohesive, single-responsibility classes
- No TODO comments or stub implementations — fully implement everything
Robustness Requirements
- Validate inputs at method entry (null checks, range validation)
- Use try-catch for all I/O and external operations
- Use try-with-resources for files, streams, connections
- Handle errors gracefully with meaningful messages
Configuration Requirements
- No hardcoded file paths or credentials — use environment variables
- No magic numbers — use named constants
- Make limits and timeouts configurable
Documentation Requirements
- Add COBOL references:
// COBOL equivalent: BNK1CRA.cbl 145-167 - Document assumptions made during conversion
- Add Javadoc to public methods
Testing Requirements
If test fixtures exist (see cobol-build-setup skill):
- Create a JUnit test class for each migrated program
- Load inputs from fixtures, assert output matches expected (golden) output
- All tests must pass before migration is complete
References
- See references/cobol-to-java-example.md for a complete transformation example
- See references/datatype-mappings.md for COBOL→Java type mappings
Done When
✓ Code compiles without errors ✓ All JUnit tests pass (Java output matches COBOL golden output) ✓ No TODO or stub implementations remain ✓ COBOL references documented in comments
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 60 lines · 31 tokens per session scan A 59e8581f4935
to-java-migration is a skill published in the GitHub repository OpenHands/extensions (167 stars, last pushed today), licensed MIT. It adds 31 tokens to every session and 450 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
java-affected-tests
Use before opening or updating an OpenMetadata PR that changes Java, a JSON schema, an index mapping, a SQL migration, seed data or a pom — PR CI no longer runs the Java integration tests (they run only in the merge queue) and the JavaUIIT/search-it suites run only nightly, so this selects the unit tests and…
azure-security-keyvault-secrets-java
Azure Key Vault Secrets Java SDK for secret management. Use when storing, retrieving, or managing passwords, API keys, connection strings, or other sensitive configuration data.
azure-ai-anomalydetector-java
Build anomaly detection applications with Azure AI Anomaly Detector SDK for Java. Use when implementing univariate/multivariate anomaly detection, time-series analysis, or AI-powered monitoring.
azure-communication-chat-java
Build real-time chat applications with Azure Communication Services Chat Java SDK. Use when implementing chat threads, messaging, participants, read receipts, typing notifications, or real-time chat features.
azure-communication-common-java
Azure Communication Services common utilities for Java. Use when working with CommunicationTokenCredential, user identifiers, token refresh, or shared authentication across ACS services.
azure-ai-agents-persistent-java
Azure AI Agents Persistent SDK for Java. Low-level SDK for creating and managing AI agents with threads, messages, runs, and tools. Triggers: "PersistentAgentsClient", "persistent agents java", "agent threads java", "agent runs java", "streaming agents java".