📦 Understanding Outputs and Metadata

Once you run a method in CCP, the platform doesn’t just give you output files — it also generates structured metadata describing what happened, how, and with what.

This guide helps you understand:

Where your results go
What kind of metadata is available
How to use that metadata for traceability and reproducibility

📂 1. Where Are Outputs Saved?

Every method writes output files to a shared folder inside the container:

/ccp_data/

Any file written there:

Will be listed in the execution result
Can be downloaded individually

💡 Tip: always write or move your results (images, CSVs, logs) to /ccp_data/.

🧾 2. What Are Metadata Files?

Alongside the actual output, CCP generates a series of metadata files. These help track:

Which method was run
With which parameters and inputs
On which infrastructure
By which user (if available)
When and how the job ended

These files are included in every execution archive.

📄 3. Key Metadata Files Explained

Filename	What it contains
`metadata_method.json`	Static info about the method: name, version, parameters
`metadata_request.json`	The input values passed by the user
`metadata_jobStatus.json`	Execution state (e.g. finished, failed), timestamps
`metadata_infrastructure.json`	Where the job was run (engine, VM, etc.)
`metadata_provo.xml`	Provenance file in W3C PROV format
`outputs_stdout.txt`	What your script printed to stdout
`outputs_stderr.txt`	What your script printed to stderr (warnings/errors)

These are saved inside the execution directory, together with your actual outputs.

🔁 Example: Reproducibility

Let’s say you run a model training method and want to:

Know which parameters were used
Retrieve the training data file
Share or repeat the same run later

You can do all of that using:

metadata_request.json → to see what was passed
metadata_provo.xml → to trace input/output relationships
outputs_ccp-entrypoint.sh → to inspect the actual shell command used

📎 Best Practices

Enable archiving if you want to keep full metadata + files together
Use metadata to document your experiments
Attach metadata_provo.xml when publishing or sharing results