Registry / serialization / jiter
library0.16.0pypypi✓ verified 24d ago

jiter is a fast iterable JSON parser for Python, currently at version 0.13.0, released on February 2, 2026. It is actively maintained with a release cadence of approximately every 2-3 months.

pip install jiter
INSTALL
IMPORT
SIG · JITER
J
jiter
serializationpythonv0.16.0
Install
1.8s avg
Import
Disk
17MB
Pass rate
10/ 10
Env Coverage10 / 10
glibc
3.93.13
musl
3.93.13
Install & Compatibility
Where this runs
tested against v0.16.0 · pip install
no network on importno background threads
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
musl
py 3.103.95 runs
installs and imports cleanly · install 0.0s · import 0.000s · 19.1MB
glibc
py 3.103.95 runs
installs and imports cleanly · install 1.8s · import 0.000s · 19MB
17MB installed
● package 17MB
Code
Verified usage

Verified import paths — ran on the pinned version, not inferred.

from_json
from jiter import from_json
Ensure correct import path to access the from_json function.

A simple example demonstrating how to parse JSON data using jiter.

import os from jiter import from_json json_data = b'{"name": "John", "age": 30}' parsed_data = from_json(json_data) print(parsed_data) # Output: {'name': 'John', 'age': 30}
Debug
Known issues
breakingIn version 0.13.0, PyO3 was bumped to 0.28, which may require adjustments in Rust bindings if used.
fix
Update your Rust dependencies to be compatible with PyO3 0.28.
affects: 0.13.0
deprecatedThe 'jiter-pupy' package is a pure Python implementation of jiter and is no longer maintained.
fix
Use the official 'jiter' package for continued support and updates.
affects: All
Errors
Common errors & fixes
ModuleNotFoundError: No module named 'jiter'
The 'jiter' package is not installed in the current Python environment or is not accessible to the running script.
fix
Install the package using pip: `pip install jiter`
ERROR: Failed to build 'jiter' when installing build dependencies
This error often occurs during installation when `pip` or `poetry` cannot compile the underlying Rust extension for 'jiter', possibly due to missing build tools (like Rust toolchain or C compiler) or environment-specific issues (e.g., specific Python versions or operating systems).
fix
Ensure you have the Rust toolchain installed (e.g., `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`). If using poetry, try `poetry add jiter --build=venv` or manually install with pip if the environment is complex. For some environments like Chaquopy, specific `openai` versions might resolve conflicts.
ValueError: JSON input is incomplete
The `jiter.from_json()` function was called with JSON bytes that are syntactically incomplete, and `partial_mode` was set to `False` (the default), which requires well-formed JSON.
fix
Provide complete and valid JSON bytes to `jiter.from_json()`, or set `partial_mode=True` to allow parsing of incomplete JSON and discard the trailing incomplete string, or `partial_mode='trailing-strings'` to include it. 
Example:
```python
import jiter
# Fix: Provide complete JSON
complete_json = b'{"key": "value"}'
parsed_data = jiter.from_json(complete_json)

# Alternative: Allow partial JSON
partial_json = b'{"key": "incomplete st'
parsed_data_partial = jiter.from_json(partial_json, partial_mode=True)
```
ValueError: Duplicate key found
The `jiter.from_json()` function encountered a JSON object containing duplicate keys, and the `catch_duplicate_keys` option was set to `True`.
fix
Ensure the JSON input does not contain objects with duplicate keys, or set `catch_duplicate_keys=False` to allow `jiter` to silently handle (typically by using the last encountered value) duplicate keys. 
Example:
```python
import jiter
# Fix: Remove duplicate key
valid_json = b'{"key1": "value1", "key2": "value2"}'
parsed_data = jiter.from_json(valid_json, catch_duplicate_keys=True)

# Alternative: Allow duplicate keys (last one wins by default if not caught)
duplicate_key_json = b'{"key": "value1", "key": "value2"}'
parsed_data_allowed = jiter.from_json(duplicate_key_json, catch_duplicate_keys=False)
```
Upgrade
Version history
0.16.0latest on PyPI · released Jun 29, 2026
Audit
Dependencies
pydanticoptionalProvides data validation and settings management using Python type annotations.
Agent activity
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node
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Resources
jiter — pip install jiter · libregistry