Offline Usage

Synwire can be used entirely offline without API keys for development, testing, and CI.

FakeChatModel

Returns pre-configured responses deterministically:

use synwire_core::language_models::{FakeChatModel, BaseChatModel};
use synwire_core::messages::Message;

let model = FakeChatModel::new(vec![
    "First response".into(),
    "Second response".into(),
]);

// Responses cycle: call 0 -> "First response", call 1 -> "Second response", call 2 -> "First response"

Features

Error injection: with_error_at(n) returns an error on call n
Stream chunking: with_chunk_size(n) splits responses into n-character chunks
Stream errors: with_stream_error_after(n) injects errors after n chunks
Call tracking: call_count() and calls() for assertions

FakeEmbeddings

Returns deterministic embedding vectors:

use synwire_core::embeddings::{FakeEmbeddings, Embeddings};

let embeddings = FakeEmbeddings::new(32); // 32-dimensional vectors
let vectors = embeddings.embed_documents(&["hello".into()]).await?;

InMemoryVectorStore

Full vector store implementation with no external dependencies:

use synwire_core::vectorstores::InMemoryVectorStore;

let store = InMemoryVectorStore::new();

InMemoryCheckpointSaver

In-memory checkpoint storage:

use synwire_checkpoint::memory::InMemoryCheckpointSaver;

let saver = InMemoryCheckpointSaver::new();

Test utilities

The synwire-test-utils crate provides:

Proptest strategies for all core types (messages, documents, embeddings, tools, channels, graphs)
Fixture builders (DocumentBuilder, MessageBuilder, PromptTemplateBuilder, ToolSchemaBuilder)
Re-exports of all strategy modules

All tests in the workspace run with cargo nextest run without any environment variables. Integration tests requiring live APIs are behind feature flags or in separate test files excluded from default runs.

Disabling network features

For air-gapped environments:

[dependencies]
synwire-core = { version = "0.1", default-features = false }

This removes reqwest and backoff dependencies. Use FakeChatModel and FakeEmbeddings exclusively.

Synwire Documentation