feat(llm): route adapters by provider

packages/compact/compact-basic/src/index.ts

@@ -294,8 +294,8 @@ export class BasicCompactService extends CompactService {
    * loop step: it does not run the `agent/request` waterfall (that seam shapes
    * the loop's conversation requests); per-call
    * interception happens at `llm/stream` like any other direct call. The model
-   * comes from `BasicCompactConfig.summarizationModel`, falling back to the
-   * agent's own model.
+   * target comes from the explicit summarization provider/model pair, falling
+   * back to the last logged request target and then the agent's creation options.
    * Override in a subclass for a template or remote summarizer.
    *
    * Honors the adapter failure contract: an adapter may report a model failure
@@ -307,23 +307,27 @@ export class BasicCompactService extends CompactService {
    * down the in-flight summarization rather than orphaning the model call.
    *
    * Returns the summary blocks TOGETHER with the call envelope it actually
-   * used (`model`, `maxTokens`) — the caller logs the envelope on the
+   * used (`provider`, `model`, `maxTokens`) — the caller logs the envelope on the
    * `compact/summary` provenance event, so an overriding subclass (template
    * or remote summarizer) reports its own envelope honestly.
    *
    * @param text - plain-text rendering of the conversation region to condense.
-   * @param agent - supplies the fallback model and the session id stamped on
-   *   the call; throws when neither it nor the config names a model.
+   * @param agent - supplies the request-header/creation fallback target and the
+   *   session id stamped on the call; throws when no complete target exists.
    * @param signal - optional abort signal, forwarded into the model call.
    * @returns the text-only summary blocks plus the call envelope used
-   *   (`model`, and `maxTokens` when the summarizer has a cap).
+   *   (`provider`, `model`, and `maxTokens` when the summarizer has a cap).
    */
   async summarize(
     text: string, agent: Agent, signal?: AbortSignal,
-  ): Promise<{ summary: ContentBlock[]; model: string; maxTokens?: number }> {
+  ): Promise<{ summary: ContentBlock[]; provider: string; model: string; maxTokens?: number }> {
     const assembler = new BlockAssembler()
+    const logged = agent.session.requestHeader()?.config
+    const provider = this.config.summarizationProvider || logged?.provider || agent.options.provider || ''
+    const model = this.config.summarizationModel || logged?.model || agent.options.model || ''
     const options: GenerateOptions = {
-      model: this.config.summarizationModel || agent.options.model || '',
+      provider,
+      model,
       messages: [{
         role: 'user',
         content: [{ type: 'text', text: `Summarize this conversation history:\n\n${text}\n\nSummary:` }],
@@ -335,8 +339,8 @@ export class BasicCompactService extends CompactService {
     // exactOptionalPropertyTypes: only set `signal` when present — assigning
     // `undefined` to an optional `signal?: AbortSignal` is a type error.
     if (signal) options.signal = signal
-    if (!options.model) {
-      throw new Error('no model available for summarization: set BasicCompactConfig.summarizationModel or AgentOptions.model')
+    if (!options.provider || !options.model) {
+      throw new Error('no provider/model available for summarization: set both summarization fields or provide a logged/agent target')
     }
     for await (const chunk of this.ctx.llm.stream(options)) {
       assembler.push(chunk)
@@ -353,7 +357,7 @@ export class BasicCompactService extends CompactService {
     // config.maxTokens is required and validated positive, so this backend's
     // envelope always carries the cap; the return type's optionality exists
     // for overriding subclasses whose summarizer has none.
-    return { summary, model: options.model, maxTokens: this.config.maxTokens }
+    return { summary, provider: options.provider, model: options.model, maxTokens: this.config.maxTokens }
   }
 
   // ---- Core API (implements the abstract contract) ----
@@ -511,7 +515,7 @@ export class BasicCompactService extends CompactService {
     try {
       // --- Extract text and summarize ---
       const text = renderTranscript(session.events, shadowedSeqs)
-      const { summary, model, maxTokens } = await this.summarize(text, agent, signal)
+      const { summary, provider, model, maxTokens } = await this.summarize(text, agent, signal)
 
       // Estimate token count of the shadowed content for provenance.
       let shadowedTokenCount = 0
@@ -533,6 +537,7 @@ export class BasicCompactService extends CompactService {
         shadowedRange: { start, end },
         shadowedSeqs,
         shadowedTokenCount,
+        provider,
         model,
         ...maxTokens !== undefined ? { maxTokens } : {},
       })

packages/compact/compact-basic/src/types.ts

@@ -24,7 +24,9 @@ export interface BasicCompactConfig {
   thresholdRatio: number
   /** Number of tokens of recent context to retain during compaction. */
   retainTokens: number
-  /** Model to use for summarization (`''` — uses the agent's model). */
+  /** Provider to use for summarization (`''` with an empty model inherits the conversation target). */
+  summarizationProvider: string
+  /** Model to use for summarization (`''` with an empty provider inherits the conversation target). */
   summarizationModel: string
   /** Provider generation cap for the summarization call. */
   maxTokens: number
@@ -70,6 +72,12 @@ export function resolveConfig(config: BasicCompactConfig): ResolvedConfig {
   if (typeof resolved.summarizationModel !== 'string') {
     throw new Error('BasicCompactConfig: summarizationModel must be a string.')
   }
+  if (typeof resolved.summarizationProvider !== 'string') {
+    throw new Error('BasicCompactConfig: summarizationProvider must be a string.')
+  }
+  if ((resolved.summarizationProvider.length === 0) !== (resolved.summarizationModel.length === 0)) {
+    throw new Error('BasicCompactConfig: summarizationProvider and summarizationModel must both be empty or both be set.')
+  }
   if (typeof resolved.auto !== 'boolean') {
     throw new Error('BasicCompactConfig: auto must be a boolean.')
   }