capture-json¶

Parses a single JSON file and embeds its parsed content in the run output under the content field.

Use Cases¶

Make experiment hyperparameters queryable across runs
Record the exact config used by a script in a structured, indexable form
Compose multiple capture-json entries to capture several config files

Configuration¶

Required Options¶

Option	Type	Description
`path`	string	Path to the JSON file to parse, relative to project root.

Example¶

[[pre-run.hooks]]
id = "capture-json"
path = "config/sat1/orbit.json"

Output Example¶

The content field contains the parsed JSON. The configured path is not duplicated in the output body — it is already preserved in the standard __meta.config.path field injected by the orchestrator.

{
  "__meta": {
    "id": "capture-json",
    "config": {
      "path": "config/sat1/orbit.json"
    },
    "success": true
  },
  "content": {
    "a": 1.42,
    "b": "LEO"
  }
}

To distinguish multiple capture-json outputs (e.g., two files with the same basename), filter on __meta.config.path.

Composing Multiple Files¶

This hook captures exactly one file per instance. Register one entry per config file to capture them all:

[[pre-run.hooks]]
id = "capture-json"
path = "config/sat1/orbit.json"

[[pre-run.hooks]]
id = "capture-json"
path = "config/sat2/orbit.json"

Each entry produces its own row in pre-run.json with its own content field; the configured path is available under __meta.config.path.

Error Behaviour¶

The hook fails (recorded with __meta.success: false) when:

The file does not exist or is unreadable (Io error)
The file content is not valid JSON (Json error)

A failing capture-json does not stop other hooks from running.