feat: add baseURL and apiKey support for OpenAI-compatible APIs

Enable connecting to any OpenAI-compatible API (Ollama, vLLM, LM Studio,
etc.) by adding baseURL and apiKey fields to AgentConfig and
OrchestratorConfig, threaded through to adapter constructors.

- OpenAIAdapter and AnthropicAdapter accept optional baseURL
- createAdapter() forwards baseURL to both adapters, warns if used with copilot
- All execution paths (runAgent, runTeam coordinator, buildPool) merge defaults
- Fully backward compatible — omitting new fields preserves existing behavior

src/agent/agent.ts

@@ -109,7 +109,7 @@ export class Agent {
     }
 
     const provider = this.config.provider ?? 'anthropic'
-    const adapter = await createAdapter(provider)
+    const adapter = await createAdapter(provider, this.config.apiKey, this.config.baseURL)
 
     const runnerOptions: RunnerOptions = {
       model: this.config.model,

src/llm/adapter.ts

@@ -54,24 +54,29 @@ export type SupportedProvider = 'anthropic' | 'copilot' | 'openai'
  *
  * @param provider - Which LLM provider to target.
  * @param apiKey   - Optional API key override; falls back to env var.
+ * @param baseURL  - Optional base URL for OpenAI-compatible APIs (Ollama, vLLM, etc.).
  * @throws {Error} When the provider string is not recognised.
  */
 export async function createAdapter(
   provider: SupportedProvider,
   apiKey?: string,
+  baseURL?: string,
 ): Promise<LLMAdapter> {
   switch (provider) {
     case 'anthropic': {
       const { AnthropicAdapter } = await import('./anthropic.js')
-      return new AnthropicAdapter(apiKey)
+      return new AnthropicAdapter(apiKey, baseURL)
     }
     case 'copilot': {
+      if (baseURL) {
+        console.warn('[open-multi-agent] baseURL is not supported for the copilot provider and will be ignored.')
+      }
       const { CopilotAdapter } = await import('./copilot.js')
       return new CopilotAdapter(apiKey)
     }
     case 'openai': {
       const { OpenAIAdapter } = await import('./openai.js')
-      return new OpenAIAdapter(apiKey)
+      return new OpenAIAdapter(apiKey, baseURL)
     }
     default: {
       // The `never` cast here makes TypeScript enforce exhaustiveness.

src/llm/anthropic.ts

@@ -189,9 +189,10 @@ export class AnthropicAdapter implements LLMAdapter {
 
   readonly #client: Anthropic
 
-  constructor(apiKey?: string) {
+  constructor(apiKey?: string, baseURL?: string) {
     this.#client = new Anthropic({
       apiKey: apiKey ?? process.env['ANTHROPIC_API_KEY'],
+      baseURL,
     })
   }
 

src/llm/openai.ts

@@ -69,9 +69,10 @@ export class OpenAIAdapter implements LLMAdapter {
 
   readonly #client: OpenAI
 
-  constructor(apiKey?: string) {
+  constructor(apiKey?: string, baseURL?: string) {
     this.#client = new OpenAI({
       apiKey: apiKey ?? process.env['OPENAI_API_KEY'],
+      baseURL,
     })
   }
 

src/orchestrator/orchestrator.ts

@@ -341,8 +341,8 @@ async function buildTaskPrompt(task: Task, team: Team): Promise<string> {
  */
 export class OpenMultiAgent {
   private readonly config: Required<
-    Omit<OrchestratorConfig, 'onProgress'>
-  > & Pick<OrchestratorConfig, 'onProgress'>
+    Omit<OrchestratorConfig, 'onProgress' | 'defaultBaseURL' | 'defaultApiKey'>
+  > & Pick<OrchestratorConfig, 'onProgress' | 'defaultBaseURL' | 'defaultApiKey'>
 
   private readonly teams: Map<string, Team> = new Map()
   private completedTaskCount = 0
@@ -360,6 +360,8 @@ export class OpenMultiAgent {
       maxConcurrency: config.maxConcurrency ?? DEFAULT_MAX_CONCURRENCY,
       defaultModel: config.defaultModel ?? DEFAULT_MODEL,
       defaultProvider: config.defaultProvider ?? 'anthropic',
+      defaultBaseURL: config.defaultBaseURL,
+      defaultApiKey: config.defaultApiKey,
       onProgress: config.onProgress,
     }
   }
@@ -405,7 +407,13 @@ export class OpenMultiAgent {
    * @param prompt - The user prompt to send.
    */
   async runAgent(config: AgentConfig, prompt: string): Promise<AgentRunResult> {
-    const agent = buildAgent(config)
+    const effective: AgentConfig = {
+      ...config,
+      provider: config.provider ?? this.config.defaultProvider,
+      baseURL: config.baseURL ?? this.config.defaultBaseURL,
+      apiKey: config.apiKey ?? this.config.defaultApiKey,
+    }
+    const agent = buildAgent(effective)
     this.config.onProgress?.({
       type: 'agent_start',
       agent: config.name,
@@ -462,6 +470,8 @@ export class OpenMultiAgent {
       name: 'coordinator',
       model: this.config.defaultModel,
       provider: this.config.defaultProvider,
+      baseURL: this.config.defaultBaseURL,
+      apiKey: this.config.defaultApiKey,
       systemPrompt: this.buildCoordinatorSystemPrompt(agentConfigs),
       maxTurns: 3,
     }
@@ -792,6 +802,8 @@ export class OpenMultiAgent {
         ...config,
         model: config.model,
         provider: config.provider ?? this.config.defaultProvider,
+        baseURL: config.baseURL ?? this.config.defaultBaseURL,
+        apiKey: config.apiKey ?? this.config.defaultApiKey,
       }
       pool.add(buildAgent(effective))
     }

src/types.ts

@@ -187,6 +187,14 @@ export interface AgentConfig {
   readonly name: string
   readonly model: string
   readonly provider?: 'anthropic' | 'copilot' | 'openai'
+  /**
+   * Custom base URL for OpenAI-compatible APIs (Ollama, vLLM, LM Studio, etc.).
+   * Note: local servers that don't require auth still need `apiKey` set to a
+   * non-empty placeholder (e.g. `'ollama'`) because the OpenAI SDK validates it.
+   */
+  readonly baseURL?: string
+  /** API key override; falls back to the provider's standard env var. */
+  readonly apiKey?: string
   readonly systemPrompt?: string
   /** Names of tools (from the tool registry) available to this agent. */
   readonly tools?: readonly string[]
@@ -286,6 +294,8 @@ export interface OrchestratorConfig {
   readonly maxConcurrency?: number
   readonly defaultModel?: string
   readonly defaultProvider?: 'anthropic' | 'copilot' | 'openai'
+  readonly defaultBaseURL?: string
+  readonly defaultApiKey?: string
   onProgress?: (event: OrchestratorEvent) => void
 }