# jbevain/cecil

Cecil is a library to inspect, modify and create .NET programs and libraries.

Repository: https://github.com/jbevain/cecil
Canonical: https://ross.abutalabs.com/products/cecil
Language: C#
License: MIT
License Family: permissive
Topics: dotnet, library, bytecode, cil, c-sharp, mono
Last push: 2025-09-11T16:57:23+00:00

## Health v2 (maintenance only)
Score: 41/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 41, release rhythm 8, longevity 100
- inputs: {"age_days": 5987, "days_push": 356, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2994, forks 654 (observed 2026-08-28T04:07:36.247824+00:00)

## What it is
Mono.Cecil is a C# library for inspecting, modifying, and generating .NET assemblies in ECMA CIL form. It provides a powerful object model over .NET binaries without requiring assembly loading via Reflection.

## Use cases
- analyze .NET assemblies without loading them via reflection
- rewrite IL code in existing .NET binaries
- inject instrumentation or logging code into assemblies at build time
- build static analysis tools for .NET programs
- generate new .NET assemblies programmatically
- strip or modify metadata in compiled libraries

## When to choose
- you need to read or rewrite .NET IL without loading assemblies into the runtime
- you're building a weaver, analyzer, or post-build IL transformer
- you need fine-grained control over .NET metadata and CIL generation

## When to avoid
- you only need to inspect loaded types at runtime - use System.Reflection instead
- you're generating dynamic code at runtime - Reflection.Emit or source generators may fit better
- you need source-level rather than IL-level transformation

## Facets
- artifact type: library
- maturity: stable
- function: parser, compiler, developer-tools
- domain: developer-tools, programming-languages, compilers
- platform: dotnet, cross-platform
- tags: cil, il-weaving, bytecode-manipulation, reflection-emit, mono, static-analysis

## Member repositories
- jbevain/cecil (main) score 41

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:36.247824+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:47:26.233993+00:00, confidence not recorded.
  - readme: https://github.com/jbevain/cecil (fetched 2026-08-28T04:07:36.247824+00:00, sha e8ae0ecc5956)
- Data as of 2026-08-30T08:39:29.467469+00:00.