Changelog

v1.5.0

DX improvements: testing, createModel, validation, debug mode

New: `@usestratus/sdk/testing` entrypoint

Ship test utilities as a separate import so they stay out of production bundles.

import { createMockModel, textResponse, toolCallResponse } from "@usestratus/sdk/testing";

const model = createMockModel([
  toolCallResponse([{ name: "search", args: { q: "test" } }]),
  textResponse("Found 3 results"),
]);

const agent = new Agent({ name: "test", model, tools: [searchTool] });
const result = await run(agent, "Search for test");

createMockModel accepts { capture: true } to record every ModelRequest for assertions.

New: `createModel()` factory

Reads AZURE_OPENAI_ENDPOINT, AZURE_OPENAI_API_KEY, and AZURE_OPENAI_DEPLOYMENT from environment variables. Throws a StratusError with a specific message when a required value is missing.

import { createModel } from "@usestratus/sdk/azure";

const model = createModel();                   // Responses API (default)
const model = createModel("chat-completions"); // explicit backend

New: `session.wait()`

One-call convenience that drains the stream and returns the result:

session.send("What's the weather?");
const result = await session.wait();

New: Agent construction validation

The Agent constructor now validates tools at construction time:

Duplicate tool names throw StratusError
timeout <= 0 throws StratusError
Empty description logs a console.warn

Use validateAgent(agent) for programmatic access to { errors, warnings }.

New: `{ debug: true }` mode

Log model calls, tool executions, and handoffs to stderr:

await run(agent, "Hello", { debug: true });
// [stratus:model] 2026-04-02T... request to assistant {"messages":2,"tools":1}
// [stratus:model] 2026-04-02T... response from assistant {"content":"Hi!"}

Also works on sessions: createSession({ model, debug: true }).

v1.4.0

Azure Responses API: compact, background tasks, CRUD, encrypted reasoning, MCP approval

New: Compact endpoint

Shrink a conversation's context window while preserving essential information:

const compacted = await model.compact({
  input: conversationItems,
});
const followUp = await model.getResponse({
  messages: [{ role: "user", content: "Continue" }],
  rawInputItems: compacted.output,
});

Also supports compact({ previousResponseId: "resp_..." }).

New: Background tasks

Run long-running requests asynchronously (designed for reasoning models like o3):

const bg = await model.createBackgroundResponse({ messages });
// Poll until done
let response = bg;
while (response.status !== "completed") {
  await new Promise((r) => setTimeout(r, 2000));
  response = await model.retrieveResponse(response.id);
}

Cancel with model.cancelResponse(id). Resume streaming with model.streamBackgroundResponse(id, { startingAfter }).

New: Retrieve, delete, list stored responses

const response = await model.retrieveResponse("resp_abc123");
const items = await model.listInputItems("resp_abc123");
await model.deleteResponse("resp_abc123");

New: Encrypted reasoning items

Preserve reasoning context across turns in stateless mode:

const result = await model.getResponse({
  messages: [{ role: "user", content: "Solve this" }],
  modelSettings: { include: ["reasoning.encrypted_content"] },
});
// Pass reasoning items back in next turn
const followUp = await model.getResponse({
  messages: [{ role: "user", content: "Continue" }],
  rawInputItems: result.outputItems?.filter((i) => i.type === "reasoning") ?? [],
});

New: MCP approval flow

Submit mcp_approval_response via rawInputItems when using remote MCP tools with approval:

const continued = await model.getResponse({
  messages,
  previousResponseId: result.responseId,
  rawInputItems: [{
    type: "mcp_approval_response",
    approve: true,
    approval_request_id: "mcpr_123",
  }],
});

New: `rawInputItems` on ModelRequest

Append opaque items (compaction, encrypted reasoning, MCP approvals) to the Responses API input array.

New: `include` and `background` in ModelSettings

include: string[] — fields to include in response (e.g. ["reasoning.encrypted_content"])
background: boolean — run as async background task

v1.3.0

Azure feature parity: allowedTools, canUseTool, interrupt, audio, predicted output

allowedTools glob patterns on RunOptions to restrict available tools
canUseTool centralized permission callback
Graceful interrupt() on streaming runs
prediction (predicted output) in ModelSettings for Chat Completions
modalities and audio config for gpt-4o-audio models
dataSources for Azure On Your Data (RAG)

v1.2.0

Phase 6: Feature parity release

Tool timeout, isEnabled, handoff isEnabled/inputType/inputFilter
Run hooks (onAgentStart/End, onHandoff, onToolStart/End, onLlmStart/End)
Tool guardrails (input/output), guardrail results on RunResult
Error handlers for maxTurns, custom toolUseBehavior function
resetToolChoice, toolErrorFormatter, callModelInputFilter
fileSearchTool(), computerUseTool()
Hosted tool streaming events
toInputList() on RunResult

v1.1.0

Phase 5: Hosted tools and Responses API features

HostedTool type, AgentTool union, isHostedTool/isFunctionTool guards
Built-in tools: webSearchTool, codeInterpreterTool, mcpTool, imageGenerationTool
toolChoice fix for Responses API
previousResponseId/responseId tracking
AzureResponsesModelConfig.store

v1.0.0

Initial release

Agent + run() + stream() + tool() + structured output + handoffs + subagents + guardrails + hooks + tracing + sessions + cost tracking + AzureResponsesModel + AzureChatCompletionsModel.

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