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Open Source

ReLLM

Exact structure out of any language model completion.

Our verdict

Not reviewed yet

We have not reviewed ReLLM yet

No one at Enterprise DNA has checked this listing against its sources. The description comes from public listings gathered automatically. Any fact below shows where it came from and when it was last checked.

How we review records

From the listing

About ReLLM

ReLLM is a Python library that constrains language model completions to produce exact structured output, such as JSON or other formal grammars. It works by filtering the model's token probabilities at each step to only allow tokens that conform to a user-defined structure.

Best for

Developers who need deterministic, structured outputs from any language model

Use cases

  • Generating valid JSON objects from free-form LLM responses
  • Enforcing a specific schema for data extraction tasks
  • Building reliable pipelines that require parseable outputs

Notes

513 stars on GitHub. Last updated 2023-08-10. Licensed MIT.

Pros

  • Lightweight and model-agnostic, works with any completion API
  • Open source with a simple Python interface
  • Guarantees structural validity without post-processing

Cons

  • Limited to exact structure constraints, not suitable for fuzzy or probabilistic outputs
  • May slow down generation due to per-token filtering
  • Community-maintained with no official support or extensive documentation

Key facts

What we have checked

Latest version
0.0.4 (released 6 May 2023)
Checked GitHub
GitHub stars
510
Checked github api via nightly crawl, recovered from git history 20e874270887c1008f860ee0198e461a23c9e438

Each value shows when we last confirmed it and where it came from. Values we have not confirmed are left out, never guessed.

Stars and usage

How ReLLM is growing

GitHub stars

513 to 510

stars. 12 July 2026 to 26 Sept 2026, 2 readings.

Source: github api via nightly crawl, recovered from git history 20e874270887c1008f860ee0198e461a23c9e438. Checked .

Alternatives

Alternatives to ReLLM

RecordTypeHow we knowChecked
TypeChatThis is an alternative to itOpen sourceNamed in the listingNot dated

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Sources

Where this comes from

  • GitHubOfficial

    Checked · Latest version

  • github api via nightly crawl, recovered from git history 20e874270887c1008f860ee0198e461a23c9e438Registry

    Checked · GitHub stars

A source shows what was published when we checked it. It does not certify security, performance or a working installation. Read our method.

Changelog

What changed

  1. Released 0.0.4

    Source: GitHub

  2. Released 0.0.3

    Source: GitHub

Open-source & AI alternatives

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