--- title: "prompttools vs langstream" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/hegelai-prompttools-vs-rogeriochaves-langstream" tools: ["hegelai-prompttools", "rogeriochaves-langstream"] --- # prompttools vs langstream *GraphCanon updated Aug 7, 2026* ## Verdict Pick prompttools if prompttools aims to support developers in the testing and experimentation of prompts for language models as well as integrating vector databases through Python utilities; pick langstream if langStream is a Python-based tool for building robust Language Model (LLM) applications, emphasizing modularity and composability. [prompttools](http://prompttools.readthedocs.io) reports 3.0k GitHub stars, 255 forks, and 41 open issues, last pushed Feb 11, 2026. [langstream](https://rogeriochaves.github.io/langstream/) has 417 stars, 28 forks, and 3 open issues, last pushed Jan 3, 2024. Figures are from public GitHub metadata via [prompttools's repository](https://github.com/hegelai/prompttools) and [langstream's repository](https://github.com/rogeriochaves/langstream). | | [prompttools](/tools/hegelai-prompttools.md) | [langstream](/tools/rogeriochaves-langstream.md) | | --- | --- | --- | | Tagline | Open-source tools for prompt testing and experimentation | Build robust LLM applications with true composability | | Stars | 3,046 | 417 | | Forks | 255 | 28 | | Open issues | 41 | 3 | | Language | Python | Python | | Adopt for | Prompttools aims to support developers in the testing and experimentation of prompts for language models as well as integrating vector databases through Python utilities. | LangStream is a Python-based tool for building robust Language Model (LLM) applications, emphasizing modularity and composability. | | Persona | - | - | | Runtime | - | - | | License | Apache-2.0 | MIT | | Categories | Developer Tools, LLM Frameworks, Vector Databases | Developer Tools, LLM Frameworks | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [prompttools](/tools/hegelai-prompttools.md) | [langstream](/tools/rogeriochaves-langstream.md) | | --- | --- | --- | | Maintenance | Slowing (36%) | Dormant (18%) | | Days since push | 177d | 946d | | Open issues (now) | 41 | 3 | | Owner type | Organization | User | | Full report | [trust report](/tools/hegelai-prompttools/trust.md) | [trust report](/tools/rogeriochaves-langstream/trust.md) | ## Decision facts: prompttools - **Hosting:** self hosted - **Pricing:** freemium - PromptsTools is open-source under the Apache-2.0 license, making it free to use but with no official support available. - **Adopt for:** Prompttools aims to support developers in the testing and experimentation of prompts for language models as well as integrating vector databases through Python utilities. ## Decision facts: langstream - **Adopt for:** LangStream is a Python-based tool for building robust Language Model (LLM) applications, emphasizing modularity and composability. ## Choose when ### Choose prompttools if… - License: prompttools is Apache-2.0, langstream is MIT. - Pricing: PromptsTools is open-source under the Apache-2.0 license, making it free to use but with no official support available.. - Tags unique to prompttools: deep-learning, embeddings, large language models, llms. - Also covers Vector Databases. - Prompttools aims to support developers in the testing and experimentation of prompts for language models as well as integrating vector databases through Python utilities. ### Choose langstream if… - License: langstream is MIT, prompttools is Apache-2.0. - Tags unique to langstream: composability, modular development, python. - LangStream is a Python-based tool for building robust Language Model (LLM) applications, emphasizing modularity and composability. ## When NOT to use prompttools - Last GitHub push was 196 days ago (slowing maintenance, Feb 11, 2026). Validate activity before betting a new project on prompttools. - Developer Tools: A gateway is overkill when you're pinned to a single provider and model. - LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. - Vector Databases: Don't reach for a dedicated vector DB under ~100k vectors; pgvector on your existing Postgres is simpler to operate. ## When NOT to use langstream - Last GitHub push was 965 days ago (dormant maintenance, Jan 3, 2024). Validate activity before betting a new project on langstream. - Developer Tools: A gateway is overkill when you're pinned to a single provider and model. - LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. ## Common questions ### What is the difference between prompttools and langstream? prompttools: Open-source tools for prompt testing and experimentation. langstream: Build robust LLM applications with true composability. See the comparison table for live GitHub stats and shared categories. ### When should I choose prompttools over langstream? Choose prompttools over langstream when License: prompttools is Apache-2.0, langstream is MIT; Pricing: PromptsTools is open-source under the Apache-2.0 license, making it free to use but with no official support available.; Tags unique to prompttools: deep-learning, embeddings, large language models, llms; Also covers Vector Databases; Prompttools aims to support developers in the testing and experimentation of prompts for language models as well as integrating vector databases through Python utilities. ### When should I choose langstream over prompttools? Choose langstream over prompttools when License: langstream is MIT, prompttools is Apache-2.0; Tags unique to langstream: composability, modular development, python; LangStream is a Python-based tool for building robust Language Model (LLM) applications, emphasizing modularity and composability. ### When should I avoid prompttools? Last GitHub push was 196 days ago (slowing maintenance, Feb 11, 2026). Validate activity before betting a new project on prompttools. Developer Tools: A gateway is overkill when you're pinned to a single provider and model. LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. Vector Databases: Don't reach for a dedicated vector DB under ~100k vectors; pgvector on your existing Postgres is simpler to operate. ### When should I avoid langstream? Last GitHub push was 965 days ago (dormant maintenance, Jan 3, 2024). Validate activity before betting a new project on langstream. Developer Tools: A gateway is overkill when you're pinned to a single provider and model. LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. ### Is prompttools or langstream more popular on GitHub? prompttools has more GitHub stars (3,046 vs 417). Stars measure visibility, not whether either tool fits your constraints. ### Are prompttools and langstream open source? Yes - both are open-source projects on GitHub (prompttools: Apache-2.0, langstream: MIT). ### Where can I find alternatives to prompttools or langstream? GraphCanon lists graph-backed alternatives at [prompttools alternatives](/tools/hegelai-prompttools/alternatives) and [langstream alternatives](/tools/rogeriochaves-langstream/alternatives) ([prompttools markdown twin](/tools/hegelai-prompttools/alternatives.md), [langstream markdown twin](/tools/rogeriochaves-langstream/alternatives.md)), ranked by typed relationship edges rather than popularity votes. ### Is there a machine-readable version of this comparison? Yes. The markdown twin at [this comparison](/compare/hegelai-prompttools-vs-rogeriochaves-langstream.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, prompttools or langstream? prompttools: Slowing. langstream: Dormant. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance. ### Where are the full trust reports for prompttools and langstream? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [prompttools trust report](/tools/hegelai-prompttools/trust); [langstream trust report](/tools/rogeriochaves-langstream/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=hegelai-prompttools`](/api/graphcanon/graph?tool=hegelai-prompttools) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_