Python JSON

The json module encodes Python objects to JSON text and decodes JSON text back into Python data structures. It is the default interchange layer for APIs, tool calling, and many agent logs.

Core Concepts

• dump and dumps serialize to a file-like object or string.
• load and loads deserialize from a file-like object or string.
• Custom serialization uses default= or a JSONEncoder subclass.
• Custom decoding uses hooks such as object_hook, object_pairs_hook, and numeric parsers.

Significance for Agents

• Tool-calling payloads and model I/O often cross JSON boundaries, so serialization choices affect determinism and recoverability.
• The module accepts some JavaScript-style numeric values by default, which is convenient but not fully strict JSON behavior.
• Parsing untrusted JSON can consume significant resources; size and trust boundaries still matter.

Practical Heuristics

• Use explicit schemas upstream and validate decoded payloads downstream.
• Keep output deterministic when diffability matters by choosing indentation and key ordering intentionally.
• Avoid writing multiple top-level objects to the same file with repeated dump() calls because JSON is not a framed protocol.

References

• python-standard-library-hubs
• python-moc
• pydantic
• json