mermaid_cli/providers/model/
anthropic.rs

1//! Anthropic provider — wraps `models::adapters::anthropic::AnthropicAdapter`.
2//!
3//! Same pattern as `ollama.rs`: the adapter handles the wire format
4//! (`cache_control` blocks, extended-thinking signature round-trip);
5//! this wrapper plumbs `ChatRequest` / `StreamContext` into it.
6//!
7//! Anthropic is the one provider that emits a `provider_continuation`
8//! that MUST round-trip on the next request. The adapter's
9//! `ModelResponse.provider_continuation` already carries it; we forward
10//! that onto the `FinalResponse` so the reducer can commit it via
11//! `ChatMessage::with_provider_continuation`.
12
13use async_trait::async_trait;
14
15use mermaid_domain::ChatRequest;
16use mermaid_model::models::adapters::anthropic::AnthropicAdapter;
17use mermaid_model::models::{Model, ModelConfig, ModelError, Result};
18
19use super::super::ctx::{FinalResponse, StreamContext, StreamEvent};
20use super::{ContextSizing, ModelProvider, resolve_limits_cached};
21use mermaid_model::models::ModelCapabilities;
22
23/// Anthropic's Messages-API root, and the env var its key lives in.
24///
25/// One definition, next to the provider, like `meta`'s. `ProviderFactory`
26/// builds the endpoint from these and `providers::discovery` reports it from
27/// the same constants — the literal used to be spelled out separately in both.
28pub const DEFAULT_BASE_URL: &str = "https://api.anthropic.com/v1";
29pub const DEFAULT_API_KEY_ENV: &str = "ANTHROPIC_API_KEY";
30
31/// Anthropic adapter fronted by `ModelProvider`.
32pub struct AnthropicProvider {
33    adapter: AnthropicAdapter,
34    capabilities: ModelCapabilities,
35}
36
37impl AnthropicProvider {
38    /// Wrap a fresh [`AnthropicAdapter`] as a `ModelProvider`.
39    ///
40    /// # Errors
41    ///
42    /// Only [`AnthropicAdapter::new`]'s — the HTTP client build. The API is
43    /// not contacted here, so an invalid key or unreachable `base_url` still
44    /// constructs and fails on the first request.
45    pub fn new(api_key: String, model_name: String, base_url: String) -> Result<Self> {
46        let adapter = AnthropicAdapter::new(api_key, model_name, base_url)?;
47        let capabilities = adapter.capabilities().clone().with_provider_continuation();
48        Ok(Self {
49            adapter,
50            capabilities,
51        })
52    }
53}
54
55#[async_trait]
56impl ModelProvider for AnthropicProvider {
57    fn capabilities(&self) -> &ModelCapabilities {
58        &self.capabilities
59    }
60
61    /// Live limit discovery via Anthropic's Models API (`GET /v1/models/
62    /// {id}` → `max_input_tokens` window + `max_tokens` output ceiling).
63    /// Cache-first via `provider_probes` (TTL-bounded), one live fetch on a
64    /// miss; a fetch failure resolves all-`None` (adapter floors apply).
65    async fn resolve_context_window(&self, request: &ChatRequest) -> ContextSizing {
66        let _ = request;
67        let model = Model::name(&self.adapter).to_string();
68        let limits =
69            resolve_limits_cached("anthropic", &model, || self.adapter.fetch_model_limits()).await;
70        let window = limits.as_ref().and_then(|l| l.max_context_tokens);
71        ContextSizing {
72            model_max: window,
73            effective: window,
74            source: None,
75            max_output: limits.as_ref().and_then(|l| l.max_output_tokens),
76        }
77    }
78
79    async fn chat(&self, request: ChatRequest, ctx: StreamContext) -> Result<FinalResponse> {
80        let config = build_model_config(&request);
81        // F2: ordered relay — see stream_bridge docs.
82        let (relay_tx, relay_handle) = super::stream_bridge::ordered_relay(ctx.sink.clone());
83        let callback = super::stream_bridge::forward_callback(relay_tx.clone());
84        let chat_fut = self
85            .adapter
86            .chat(&request.messages, &config, Some(callback));
87
88        let response = tokio::select! {
89            biased;
90            _ = ctx.token.cancelled() => {
91                return Err(ModelError::Cancelled);
92            },
93            r = chat_fut => r?,
94        };
95
96        let usage = response.usage.clone();
97        let provider_continuation = response.provider_continuation.clone();
98        let stop_reason = response.stop_reason.clone();
99        // Terminal Done through the ordered relay, then drain (see stream_bridge).
100        let _ = relay_tx.send(StreamEvent::Done {
101            usage: usage.clone(),
102            provider_continuation: provider_continuation.clone(),
103            stop_reason: stop_reason.clone(),
104        });
105        drop(relay_tx);
106        mermaid_model::utils::join_logged(relay_handle.take(), "stream_relay").await;
107
108        Ok(FinalResponse {
109            usage,
110            provider_continuation,
111            tool_calls: response.tool_calls.unwrap_or_default(),
112            stop_reason,
113        })
114    }
115}
116
117fn build_model_config(request: &ChatRequest) -> ModelConfig {
118    ModelConfig {
119        model: request.model_id.clone(),
120        temperature: request.temperature,
121        max_tokens: request.max_tokens,
122        reasoning: request.reasoning,
123        system_prompt: Some(request.system_prompt.clone()),
124        dynamic_system_suffix: request.instructions.clone(),
125        tools: request.tools.iter().map(|t| t.to_openai_json()).collect(),
126        resolved_context_window: request.resolved_context_window,
127        resolved_max_output: request.resolved_max_output,
128        // The adapter maps this to `output_config.format` (native
129        // structured output); client-side validation stays the final gate.
130        output_schema: request.output_schema.clone(),
131        ..Default::default()
132    }
133}
134
135#[cfg(test)]
136mod tests {
137    use super::*;
138
139    #[test]
140    fn build_model_config_maps_fields() {
141        let req = ChatRequest {
142            model_id: "anthropic/claude-opus-4-7".to_string(),
143            messages: vec![],
144            system_prompt: "sys".to_string(),
145            instructions: Some("MERMAID.md content".to_string()),
146            reasoning: mermaid_model::models::ReasoningLevel::XHigh,
147            temperature: 0.7,
148            max_tokens: 8192,
149            tools: vec![],
150
151            ollama_num_ctx: None,
152            ollama_allow_ram_offload: None,
153            resolved_context_window: None,
154            resolved_max_output: None,
155            output_schema: None,
156            suppress_auto_compact: false,
157            suppressed_builtin_tools: Vec::new(),
158        };
159        let cfg = build_model_config(&req);
160        assert_eq!(cfg.reasoning, mermaid_model::models::ReasoningLevel::XHigh);
161        assert_eq!(cfg.max_tokens, 8192);
162        assert_eq!(
163            cfg.dynamic_system_suffix.as_deref(),
164            Some("MERMAID.md content")
165        );
166    }
167}
mermaid_cli/providers/model/anthropic.rs

mermaid_cli/providers/model/
anthropic.rs
