langsmith
Version:
Client library to connect to the LangSmith Observability and Evaluation Platform.
186 lines (185 loc) • 9.21 kB
JavaScript
import { OTLPTraceExporter } from "@opentelemetry/exporter-trace-otlp-proto";
import * as constants from "./constants.js";
import { isTracingEnabled } from "../../env.js";
import { getEnvironmentVariable, getLangSmithEnvironmentVariable, } from "../../utils/env.js";
import { extractUsageMetadata } from "../../utils/vercel.js";
/**
* Convert headers string in format "name=value,name2=value2" to object
*/
function parseHeadersString(headersStr) {
const headers = {};
if (!headersStr)
return headers;
headersStr.split(",").forEach((pair) => {
const [name, ...valueParts] = pair.split("=");
if (name && valueParts.length > 0) {
headers[name.trim()] = valueParts.join("=").trim();
}
});
return headers;
}
/**
* LangSmith OpenTelemetry trace exporter that extends the standard OTLP trace exporter
* with LangSmith-specific configuration and span attribute transformations.
*
* This exporter automatically configures itself with LangSmith endpoints and API keys,
* based on your LANGSMITH_API_KEY and LANGSMITH_PROJECT environment variables.
* Will also respect OTEL_EXPORTER_OTLP_ENDPOINT or OTEL_EXPORTER_OTLP_HEADERS environment
* variables if set.
*
* @param config - Optional configuration object that accepts all OTLPTraceExporter parameters.
* If not provided, uses default LangSmith configuration:
* - `url`: Defaults to LangSmith OTEL endpoint (`${LANGSMITH_ENDPOINT}/otel/v1/traces`)
* - `headers`: Auto-configured with LangSmith API key and project headers
* Any provided config will override these defaults.
*/
export class LangSmithOTLPTraceExporter extends OTLPTraceExporter {
constructor(config) {
const defaultLsEndpoint = getLangSmithEnvironmentVariable("ENDPOINT") ||
"https://api.smith.langchain.com";
const defaultBaseUrl = defaultLsEndpoint.replace(/\/$/, "");
const defaultUrl = getEnvironmentVariable("OTEL_EXPORTER_OTLP_ENDPOINT") ??
`${defaultBaseUrl}/otel/v1/traces`;
// Configure headers with API key and project if available
let headers = config?.headers;
if (headers === undefined) {
let defaultHeaderString = getEnvironmentVariable("OTEL_EXPORTER_OTLP_HEADERS") ?? "";
if (!defaultHeaderString) {
const apiKey = config?.apiKey ?? getLangSmithEnvironmentVariable("API_KEY");
if (apiKey) {
defaultHeaderString = `x-api-key=${apiKey}`;
}
}
headers = parseHeadersString(defaultHeaderString);
}
super({
url: defaultUrl,
headers,
...config,
});
Object.defineProperty(this, "transformExportedSpan", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "projectName", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
this.transformExportedSpan = config?.transformExportedSpan;
this.projectName =
config?.projectName ?? getLangSmithEnvironmentVariable("PROJECT");
}
export(spans, resultCallback) {
if (!isTracingEnabled()) {
return resultCallback({ code: 0 });
}
const runExport = async () => {
for (let span of spans) {
if (this.transformExportedSpan) {
span = await this.transformExportedSpan(span);
}
if (!span.attributes[constants.GENAI_PROMPT]) {
if (span.attributes["ai.prompt"]) {
span.attributes[constants.GENAI_PROMPT] =
span.attributes["ai.prompt"];
}
if (span.attributes["ai.prompt.messages"] &&
typeof span.attributes["ai.prompt.messages"] === "string") {
let messages;
try {
messages = JSON.parse(span.attributes["ai.prompt.messages"]);
}
catch (e) {
console.error("Failed to parse ai.prompt.messages", e);
}
if (messages && Array.isArray(messages)) {
span.attributes[constants.GENAI_PROMPT] = JSON.stringify({
input: messages,
});
}
}
if (span.attributes["ai.toolCall.input"]) {
span.attributes[constants.GENAI_PROMPT] =
span.attributes["ai.toolCall.input"];
}
else if (span.attributes["ai.toolCall.args"]) {
span.attributes[constants.GENAI_PROMPT] =
span.attributes["ai.toolCall.args"];
}
}
// Iterate over all attributes starting with "ai.telemetry.metadata"
for (const [key, value] of Object.entries(span.attributes)) {
if (key.startsWith("ai.telemetry.metadata.")) {
if (key === "ai.telemetry.metadata.ls_project_name") {
span.attributes[constants.LANGSMITH_SESSION_NAME] = value;
}
else if (key === "ai.telemetry.metadata.ls_project_id") {
span.attributes[constants.LANGSMITH_SESSION_ID] = value;
}
else {
const metadataKey = key.replace("ai.telemetry.metadata.", "");
span.attributes[`${constants.LANGSMITH_METADATA}.${metadataKey}`] = value;
}
delete span.attributes[key];
}
}
if (!span.attributes[constants.GENAI_COMPLETION]) {
if (span.attributes["ai.response.text"]) {
span.attributes[constants.GENAI_COMPLETION] =
span.attributes["ai.response.text"];
}
if (span.attributes["ai.response.choices"]) {
span.attributes[constants.GENAI_COMPLETION] =
span.attributes["ai.response.choices"];
}
if (span.attributes["ai.response.object"]) {
span.attributes[constants.GENAI_COMPLETION] =
span.attributes["ai.response.object"];
}
if (span.attributes["ai.response.toolCalls"]) {
span.attributes[constants.GENAI_COMPLETION] =
span.attributes["ai.response.toolCalls"];
}
if (span.attributes["ai.toolCall.output"]) {
span.attributes[constants.GENAI_COMPLETION] =
span.attributes["ai.toolCall.output"];
}
else if (span.attributes["ai.toolCall.result"]) {
span.attributes[constants.GENAI_COMPLETION] =
span.attributes["ai.toolCall.result"];
}
}
if (typeof span.attributes["ai.operationId"] === "string" &&
constants.AI_SDK_LLM_OPERATIONS.includes(span.attributes["ai.operationId"])) {
span.attributes[constants.LANGSMITH_RUN_TYPE] = "llm";
const usageMetadata = extractUsageMetadata(span);
span.attributes[constants.LANGSMITH_USAGE_METADATA] =
JSON.stringify(usageMetadata);
}
else if (typeof span.attributes["ai.operationId"] === "string" &&
constants.AI_SDK_TOOL_OPERATIONS.includes(span.attributes["ai.operationId"])) {
span.attributes[constants.LANGSMITH_RUN_TYPE] = "tool";
if (span.attributes["ai.toolCall.name"]) {
span.attributes[constants.LANGSMITH_NAME] =
span.attributes["ai.toolCall.name"];
}
}
if (span.attributes[`${constants.LANGSMITH_METADATA}.ls_run_name`]) {
span.attributes[constants.LANGSMITH_NAME] =
span.attributes[`${constants.LANGSMITH_METADATA}.ls_run_name`];
delete span.attributes[`${constants.LANGSMITH_METADATA}.ls_run_name`];
}
if (span.attributes[constants.LANGSMITH_SESSION_NAME] === undefined &&
this.projectName !== undefined) {
span.attributes[constants.LANGSMITH_SESSION_NAME] = this.projectName;
}
}
super.export(spans, resultCallback);
};
void runExport();
}
}