> ## Documentation Index
> Fetch the complete documentation index at: https://docs.thrindex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# E0108 — IrJsonParseError

> The Graph IR JSON passed to the compiler is malformed.

<Warning>E0108: Graph IR JSON parse error</Warning>

## What happened

The compiler's capture pass received a JSON string representing the model's Graph IR (intermediate representation), but the JSON could not be parsed. It is not valid Graph IR JSON.

## Why

The Graph IR is produced by the Python SDK's extraction pass (`thx.compile` internally serializes the model to JSON before invoking the Rust compiler). If this error appears, the serialization or the transport between Python and Rust produced invalid JSON.

This error should not occur in normal usage. It indicates:

* A version mismatch between the Python SDK and the Rust compiler
* A corrupted message when the Python SDK calls the native extension

## How to fix

1. **Upgrade thrindex**: `pip install --upgrade thrindex`. Both the Python SDK and the Rust engine ship together in the wheel.
2. Rebuild from source if you are developing THRINDEX itself: `maturin develop --release`.
3. If this error appears in a released version, please file a bug report with the full error message and the thrindex version (`thrindex doctor`).

## Example

```
E0108: Graph IR JSON parse error: missing field `layers` at line 1 column 42
Why: the input is not valid Graph IR JSON (produced by thx.compile's Python extraction pass).
Fix: verify the Graph IR was produced by a current version of the thrindex Python SDK.
Docs: https://docs.thrindex.com/errors/E0108
```