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Rust API

The Rust API is documented inline via rustdoc. See docs.rs/langmail for the authoritative, versioned reference — including error variants, method receivers, and serde derivations.

Surface at a glance

Entry points and options. Payload structs (Address, CallToAction, ThreadMessage) and the provider-adapter entry point (preprocess_parsed / ParsedInput) are documented on docs.rs/langmail.

Item Description
preprocess fn preprocess(raw: &[u8]) -> Result<ProcessedEmail, LangmailError>
preprocess_with_options Preprocess with a custom PreprocessOptions
adapters::preprocess_gmail fn preprocess_gmail(msg_json: &str) -> Result<ProcessedEmail, LangmailError> — normalize a Gmail API Schema$Message (JSON) through the shared pipeline
adapters::preprocess_gmail_with_options As above, with a PreprocessOptions override
ProcessedEmail The parsed output struct
ProcessedEmail::to_llm_context Method on ProcessedEmail returning the LLM-ready string
ProcessedEmail::to_llm_context_with_options As above, with a LlmContextOptions
PreprocessOptions strip_quotes, strip_signature, max_body_length
LlmContextOptions render_mode: RenderMode
RenderMode LatestOnly | ThreadHistory
LangmailError Error variants returned by preprocess

Notes

  • preprocess returns a Result; unlike the Node and Python bindings, there is no exception channel.
  • to_llm_context is a method on ProcessedEmail, not a free function.
  • All data types (ProcessedEmail, Address, CallToAction, ThreadMessage, PreprocessOptions, LlmContextOptions, RenderMode) derive serde::Serialize / Deserialize for JSON round-tripping. LangmailError does not.
  • Provider adapters live under langmail::adapters. They take the provider's JSON as &str — serialize a Gmail users.messages.get response with serde_json::to_string and pass the result. The adapter walks payload.parts, base64url-decodes the bodies, and feeds them into the same cleaning pipeline as preprocess, so the output is byte-identical to the MIME path. Gmail-specific errors are raised as LangmailError::InvalidGmailMessage and LangmailError::BodyRequiresAttachmentFetch.