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Colfer is a code-generation tool that creates serialization/deserialization code from schema definitions, optimized for speed and binary size. It supports C, Go, Java, and JavaScript, with a straightforward compiler and public-domain license.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | pascaldekloe/colfer |
| Owner | pascaldekloe |
| Primary language | Java |
| License | CC0-1.0 — Requires review (not clearly OSI) |
| Stars | 758 |
| Forks | 55 |
| Open issues | 10 |
| Latest release | v1.8.1 (2020-06-18) |
| Last updated | 2026-02-26 |
| Source | https://github.com/pascaldekloe/colfer |
What colfer is
Colfer generates marshalling/unmarshalling code from .colf schema files for cross-language binary serialization. Built-in size limits prevent memory bombs; framing supports streaming and concatenation. Protocol inspired by Protocol Buffers but positioned as faster and smaller.
Get the colfer source
Clone the repository and explore it locally.
git clone https://github.com/pascaldekloe/colfer.gitcd colfer# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- Schema must be committed to version control; code generation is typically part of the build pipeline (Maven plugin available for Java).
- Default size limits (16 MB payload, 64k list elements) are configurable per compile target but affect all generated code—verify suitability for your data volumes.
- Field count is treated as schema version; add new fields only at the end for backward compatibility; deprecated fields should be renamed to discourage use.
- Text validation (UTF-8 handling) is not enforced during marshalling/unmarshalling; Java and JavaScript replace unmappable chars with '?', C and Go pass through malformed sequences.
- Compiler requires schema definitions in .colf format; prebuilt binaries or `go get` installation recommended to avoid adding Go toolchain dependency to build.
When to avoid it — and what to weigh
- Enumerations Required — Colfer explicitly does not support enumerations. If your domain requires type-safe enum fields, this is a hard blocker.
- Rust or Python as Primary Languages — Language support is limited to C, Go, Java, and JavaScript. Rust and Python are listed as TODO; community ports exist but lack official support.
- Evolving Schema with Many Fields — Hard limit of 127 fields per struct and no enumeration support constrains schema evolution. Complex domain models may require restructuring.
- Human-Readable Format Preferred — Colfer is binary-only. If debugging, logging, or human inspection of payloads is critical, consider text-based formats (JSON, YAML) or hybrid approaches.
License & commercial use
Colfer is released under CC0-1.0 (Creative Commons Zero v1.0 Universal), placing the software in the public domain. The format specification is free and unencumbered.
CC0-1.0 is a public-domain dedication with no restrictions on commercial use, modification, or distribution. No warranties are implied. This is not a traditional OSI-approved license but achieves similar permissiveness. Recommended to review your legal team's interpretation of public-domain software in your jurisdiction.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Active |
| Documentation | Adequate |
| License clarity | Clear |
| Deployment complexity | Low |
| DEV.co fit | Good |
| Assessment confidence | High |
Colfer includes built-in protections: hardcoded size limits prevent memory exhaustion from untrusted input, framing prevents reading outside serial boundaries, marshaller cannot produce malformed output. Fuzz testing has not revealed vulnerabilities to date, but security assurances depend on implementation maturity. UTF-8 handling is lenient (replacement rather than rejection); validate text fields at application layer if strict encoding enforcement is required. Field count is not cryptographically signed; schema tampering is not detected.
Alternatives to consider
Protocol Buffers (protobuf)
Industry standard with broader ecosystem, official support for Rust/Python, more mature tooling. Colfer positions itself as faster and smaller but protobuf has stronger community, better documentation, and richer language support.
FlatBuffers
Zero-copy deserialization and similar performance goals. Broader language support and active Google backing. Better for scenarios requiring random access to nested structures without full deserialization.
MessagePack / CBOR
Simpler, language-agnostic binary formats without code generation. Easier to debug and inspect; useful if schema is fluid or if human inspection of payloads is needed. Trade-off: larger payload sizes.
Build on colfer with DEV.co software developers
If you're building cross-language microservices, mobile backends, or streaming systems where performance and payload size matter, download a prebuilt Colfer compiler and test with your schema. Review the benchmark wiki and security guarantees before committing to production use.
Talk to DEV.coRelated open-source tools
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colfer FAQ
Can I use Colfer with Python or Rust?
What happens if I receive a payload larger than ColferSizeMax?
How do I handle schema evolution?
Is Colfer suitable for REST APIs or only RPC-like messaging?
From evaluation to production software
DEV.co pairs senior engineers with teams adopting tools like colfer. Our software development services span ai coding agents architecture, implementation, and the AI development services that increasingly sit alongside them.
Evaluate Colfer for Your Serialization Needs
If you're building cross-language microservices, mobile backends, or streaming systems where performance and payload size matter, download a prebuilt Colfer compiler and test with your schema. Review the benchmark wiki and security guarantees before committing to production use.