feat: add flows

Signed-off-by: Tomas Dvorak <toomas2d@gmail.com>

examples/flows/agent.ts

@@ -0,0 +1,78 @@
+import "dotenv/config";
+import { BeeAgent } from "bee-agent-framework/agents/bee/agent";
+import { BAMChatLLM } from "bee-agent-framework/adapters/bam/chat";
+import { z } from "zod";
+import { BaseMessage } from "bee-agent-framework/llms/primitives/message";
+import { JsonDriver } from "bee-agent-framework/llms/drivers/json";
+import { WikipediaTool } from "bee-agent-framework/tools/search/wikipedia";
+import { OpenMeteoTool } from "bee-agent-framework/tools/weather/openMeteo";
+import { ReadOnlyMemory } from "bee-agent-framework/memory/base";
+import { UnconstrainedMemory } from "bee-agent-framework/memory/unconstrainedMemory";
+import { Flow } from "bee-agent-framework/flows";
+import { createConsoleReader } from "examples/helpers/io.js";
+
+const schema = z.object({
+  answer: z.instanceof(BaseMessage).optional(),
+  memory: z.instanceof(ReadOnlyMemory),
+});
+
+const workflow = new Flow({ schema: schema })
+  .addStep("simpleAgent", async (state) => {
+    const simpleAgent = new BeeAgent({
+      llm: BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct"),
+      tools: [],
+      memory: state.memory,
+    });
+    const answer = await simpleAgent.run({ prompt: null });
+    reader.write("🤖 Simple Agent", answer.result.text);
+
+    return {
+      update: { answer: answer.result },
+      next: "critique",
+    };
+  })
+  .addStep("critique", schema.required(), async (state) => {
+    const llm = BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct");
+    const { parsed: critiqueResponse } = await new JsonDriver(llm).generate(
+      z.object({ score: z.number().int().min(0).max(100) }),
+      [
+        BaseMessage.of({
+          role: "system",
+          text: `You are an evaluation assistant who scores the credibility of the last assistant's response. Chitchatting always has a score of 100. If the assistant was unable to answer the user's query, then the score will be 0.`,
+        }),
+        ...state.memory.messages,
+        state.answer,
+      ],
+    );
+    reader.write("🧠 Score", critiqueResponse.score.toString());
+
+    return {
+      next: critiqueResponse.score < 75 ? "complexAgent" : Flow.END,
+    };
+  })
+  .addStep("complexAgent", async (state) => {
+    const complexAgent = new BeeAgent({
+      llm: BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct"),
+      tools: [new WikipediaTool(), new OpenMeteoTool()],
+      memory: state.memory,
+    });
+    const { result } = await complexAgent.run({ prompt: null });
+    reader.write("🤖 Complex Agent", result.text);
+    return { update: { answer: result } };
+  })
+  .setStart("simpleAgent");
+
+const reader = createConsoleReader();
+const memory = new UnconstrainedMemory();
+
+for await (const { prompt } of reader) {
+  const userMessage = BaseMessage.of({ role: "user", text: prompt });
+  await memory.add(userMessage);
+
+  const response = await workflow.run({
+    memory: memory.asReadOnly(),
+  });
+  await memory.add(response.state.answer!);
+
+  reader.write("🤖 Final Answer", response.state.answer!.text);
+}

examples/flows/contentCreator.ts

@@ -0,0 +1,151 @@
+import "dotenv/config.js";
+import { Flow } from "bee-agent-framework/flows";
+import { z } from "zod";
+import { BeeAgent } from "bee-agent-framework/agents/bee/agent";
+import { UnconstrainedMemory } from "bee-agent-framework/memory/unconstrainedMemory";
+import { BAMChatLLM } from "bee-agent-framework/adapters/bam/chat";
+import { createConsoleReader } from "examples/helpers/io.js";
+import { BaseMessage } from "bee-agent-framework/llms/primitives/message";
+import { DuckDuckGoSearchTool } from "bee-agent-framework/tools/search/duckDuckGoSearch";
+import { JsonDriver } from "bee-agent-framework/llms/drivers/json";
+import { isEmpty, pick } from "remeda";
+
+const schema = z.object({
+  input: z.string(),
+  output: z.string().optional(),
+
+  topic: z.string().optional(),
+  notes: z.array(z.string()).default([]),
+  plan: z.string().optional(),
+  draft: z.string().optional(),
+});
+
+const flow = new Flow({
+  schema: schema,
+  outputSchema: schema.required({ output: true }),
+})
+  .addStep("preprocess", async (state) => {
+    const llm = BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct");
+    const driver = new JsonDriver(llm);
+
+    const { parsed } = await driver.generate(
+      schema.pick({ topic: true, notes: true }).or(
+        z.object({
+          error: z.string().describe("Use this field if the user input is not a valid topic."),
+        }),
+      ),
+      [
+        BaseMessage.of({
+          role: `user`,
+          text: [
+            "Your task is to rewrite the user input so that it guides the content planner and editor to craft a blog post that perfectly aligns with the user's needs. Notes should be used only if the user complains about something.",
+            "",
+            ...[!isEmpty(state.notes) && ["# Previous Topic", state.topic, ""]],
+            ...[!isEmpty(state.notes) && ["# Previous Notes", state.notes.join("\n"), ""]],
+            "# User Query",
+            state.input,
+          ]
+            .filter(Boolean)
+            .join("\n"),
+        }),
+      ],
+    );
+
+    return "error" in parsed
+      ? { update: { output: parsed.error }, next: Flow.END }
+      : { update: pick(parsed, ["notes", "topic"]) };
+  })
+  .addStep("planner", schema.required({ topic: true }), async (state) => {
+    const llm = BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct");
+    const agent = new BeeAgent({
+      llm,
+      memory: new UnconstrainedMemory(),
+      tools: [new DuckDuckGoSearchTool()],
+    });
+
+    const { result } = await agent.run({
+      prompt: [
+        `You are a Content Planner. Your task is to create a content plan for "${state.topic}" topic.`,
+        ``,
+        `# Objectives`,
+        `1. Prioritize the latest trends, key players, and noteworthy news.`,
+        `2. Identify the target audience, considering their interests and pain points.`,
+        `3. Develop a detailed content outline including introduction, key points, and a call to action.`,
+        `4. Include SEO keywords and relevant sources.`,
+        ``,
+        ...[!isEmpty(state.notes) && ["# Notes", state.notes.join("\n"), ""]],
+      ].join("\n"),
+    });
+
+    return {
+      update: {
+        plan: result.text,
+      },
+    };
+  })
+  .addStep("writer", schema.required({ plan: true }), async (state) => {
+    const llm = BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct");
+    const output = await llm.generate([
+      BaseMessage.of({
+        role: `system`,
+        text: `You are a Content Writer. Your task is to write a compelling blog post based on the provided Context.
+
+# Context
+${state.plan}
+
+# Objectives
+- An engaging introduction
+- Insightful body paragraphs (2-3 per section)
+- Properly named sections/subtitles
+- A summarizing conclusion
+
+Ensure the content flows naturally, incorporates SEO keywords, and is well-structured.`,
+      }),
+    ]);
+
+    return {
+      update: { draft: output.getTextContent() },
+    };
+  })
+  .addStep("editor", schema.required({ draft: true }), async (state) => {
+    const llm = BAMChatLLM.fromPreset("meta-llama/llama-3-1-70b-instruct");
+    const output = await llm.generate([
+      BaseMessage.of({
+        role: `system`,
+        text: `You are an Editor. Your task is to transform the following draft blog post to a final version.
+
+# Draft
+${state.draft}
+
+# Objectives
+- Fix Grammatical errors
+- Journalistic best practices
+
+IMPORTANT: The final version must not contain any editor's comments.
+`,
+      }),
+    ]);
+
+    return {
+      update: { output: output.getTextContent() },
+    };
+  });
+
+let lastResult = {} as Flow.output<typeof flow>;
+const reader = createConsoleReader();
+for await (const { prompt } of reader) {
+  const { result } = await flow
+    .run({
+      input: prompt,
+      notes: lastResult?.notes,
+      topic: lastResult?.topic,
+    })
+    .observe((emitter) => {
+      emitter.on("start", ({ step, run }) => {
+        reader.write(`-> ▶️ ${step}`, JSON.stringify(run.state).substring(0, 200).concat("..."));
+      });
+    });
+
+  lastResult = result;
+  reader.write("🤖 Answer", lastResult.output);
+}

examples/flows/simple.ts

@@ -0,0 +1,43 @@
+import { Flow } from "bee-agent-framework/flows";
+import { z } from "zod";
+
+const schema = z.object({
+  hops: z.number().default(0),
+});
+
+const flow = new Flow({ schema })
+  .addStep("a", async (state) => ({
+    update: { hops: state.hops + 1 },
+  }))
+  .addStep("b", async (state) => ({
+    update: { hops: state.hops + 1 },
+  }))
+  .addStep("c", async (state) => ({
+    update: { hops: state.hops + 1 },
+    next: Math.random() > 0.5 ? "a" : Flow.END,
+  }))
+  .addStep("d", () => ({}))
+  .delStep("d");
+
+{
+  console.info("Example 1");
+  const result = await flow.run({ hops: 0 });
+  console.info(`-> steps`, result.steps.map((step) => step.name).join(","));
+}
+
+{
+  console.info("Example 2");
+  const result = await flow.setStart("c").run({ hops: 10 });
+  console.info(`-> steps`, result.steps.map((step) => step.name).join(","));
+}
+
+{
+  // Type utils
+  const input: Flow.input<typeof flow> = {};
+  const output: Flow.output<typeof flow> = { hops: 10 };
+  const response: Flow.run<typeof flow> = {
+    steps: [],
+    state: { hops: 1 },
+    result: { hops: 1 },
+  };
+}

package.json

@@ -39,7 +39,8 @@
           "serializer",
           "infra",
           "deps",
-          "instrumentation"
+          "instrumentation",
+          "flows"
         ]
       ]
     }

src/context.ts

@@ -97,8 +97,8 @@ export class RunContext<T extends RunInstance, P = any> extends Serializable {
     return this.controller.signal;
   }
 
-  abort() {
-    this.controller.abort();
+  abort(reason?: Error) {
+    this.controller.abort(reason);
   }
 
   constructor(