Enum FinishReason 

pub enum FinishReason {
    Stop,
    ToolUse,
    Truncated {
        reason: Option<String>,
    },
    Other(String),
}

Semantic finish reason, replacing scattered Option<String> matching.

Each variant captures a distinct end-of-turn signal from the LLM provider. Conversion helpers (FinishReason::from_openai, FinishReason::from_anthropic, FinishReason::from_responses) normalise the provider-specific strings.

Variants

Stop

Model finished naturally (OpenAI "stop" / Anthropic "end_turn").

ToolUse

Model requested tool calls (Anthropic "tool_use").

OpenAI’s "tool_calls" is consumed at the client layer as StreamChunk::ToolCall and never reaches the react loop.

Truncated

Output was truncated by the token limit.

• OpenAI: "length"
• Anthropic: "max_tokens"
• Responses API: "incomplete"

Fields

reason: Option<String>

Provider-specific reason string, if available.

Other(String)

Any other / unknown finish reason.

Implementations

impl FinishReason

pub fn from_openai(s: Option<&str>) -> Self

Normalise an OpenAI Chat Completions finish_reason value.

pub fn from_anthropic(s: Option<&str>) -> Self

Normalise an Anthropic stop_reason value.

pub fn from_responses(reason: Option<&str>) -> Self

Normalise an OpenAI Responses API status / incomplete reason.

pub fn from_raw(s: Option<&str>) -> Self

Unified conversion when the provider is unknown at compile time.

Handles the union of OpenAI Chat and Anthropic stop-reason strings, as well as the Responses API "incomplete:reason" format. OpenAI "tool_calls" is consumed client-side and never reaches here, so it is not matched.

pub fn is_truncated(&self) -> bool

Returns true if the response was truncated by the token limit.

Trait Implementations

impl Clone for FinishReason

fn clone(&self) -> FinishReason

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FinishReason

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for FinishReason

impl PartialEq for FinishReason

fn eq(&self, other: &FinishReason) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for FinishReason