Method onChainStart

packages/components/src/handler.ts:916–1150

(name: string, input: string, parentIds?: ICommonObject)

    }

    async onChainStart(name: string, input: string, parentIds?: ICommonObject) {
        const returnIds: ICommonObject = {
            langSmith: {},
            langFuse: {},
            lunary: {},
            langWatch: {},
            arize: {},
            phoenix: {},
            opik: {}
        }

        if (Object.prototype.hasOwnProperty.call(this.handlers, 'langSmith')) {
            if (!parentIds || !Object.keys(parentIds).length) {
                const parentRunConfig: RunTreeConfig = {
                    name,
                    run_type: 'chain',
                    inputs: {
                        text: input
                    },
                    serialized: {},
                    project_name: this.handlers['langSmith'].langSmithProject,
                    client: this.handlers['langSmith'].client,
                    ...this.nodeData?.inputs?.analytics?.langSmith
                }
                const parentRun = new RunTree(parentRunConfig)
                await parentRun.postRun()
                // Merge rather than replace: AnalyticHandler is a per-chatId singleton, so recursive
                // executeAgentFlow calls (e.g. iterationAgentflow) re-enter onChainStart on the same
                // instance. Replacing would drop the outer call's parent entry and orphan its trace.
                this.handlers['langSmith'].chainRun = {
                    ...this.handlers['langSmith'].chainRun,
                    [parentRun.id]: parentRun
                }
                returnIds['langSmith'].chainRun = parentRun.id
            } else {
                const parentRun: RunTree | undefined = this.handlers['langSmith'].chainRun[parentIds['langSmith'].chainRun]
                if (parentRun) {
                    const childChainRun = await parentRun.createChild({
                        name,
                        run_type: 'chain',
                        inputs: {
                            text: input
                        }
                    })
                    await childChainRun.postRun()
                    this.handlers['langSmith'].chainRun = {
                        ...this.handlers['langSmith'].chainRun,
                        [childChainRun.id]: childChainRun
                    }
                    returnIds['langSmith'].chainRun = childChainRun.id
                }
            }
        }

        if (Object.prototype.hasOwnProperty.call(this.handlers, 'langFuse')) {
            let langfuseTraceClient: LangfuseTraceClient

            if (!parentIds || !Object.keys(parentIds).length) {