For AI agents: a documentation index is available at /docs/llms.txt. Append .md to any page URL for markdown, or send Accept: text/markdown.
Amplitude AI SDK reference
This page is the developer reference for the Amplitude AI SDK. For the product-level setup overview, refer to Set up Agent Analytics. For the product concepts and how Amplitude uses the data, refer to the Agent Analytics overview and Analyze agent results.
The timeline below shows what your instrumentation produces. Click any event to inspect its shape and the call that emits it.
| [Agent] Session ID | 4ddcc6b2-1041-432a-aa8c-ebe3eccac40b |
| [Agent] Agent ID | support-chatbot |
| [Agent] Trace ID | b4f63d43-d752-4b1f-8489-d234ddf586b2 |
| $llm_message.text | I can help. Your subscription renews on Aug 15… |
| [Agent] Model Name | gpt-4o-mini |
| [Agent] Provider | openai |
| [Agent] Input Tokens | 1245 |
| [Agent] Output Tokens | 87 |
| [Agent] Latency Ms | 3420 |
| [Agent] Cost USD | 0.0012 |
s.trackAiMessage(...) or a provider wrapper.Prerequisites
- An Amplitude project with Agent Analytics enabled.
- The View Agent Analytics Objects permission. Admins grant access through role-based access control (RBAC).
- An agent codebase to instrument in Node.js or Python (or a runtime that can call the Amplitude HTTP API).
- The project's API key for the right data center. Agent Analytics runs in US and EU.
Install the SDK
npm install @amplitude/ai @amplitude/analytics-node
To have your AI coding agent install and instrument the SDK for you, refer to Instrument your agent with the AI SDK.
The packages are @amplitude/ai on npm and amplitude-ai on PyPI. For what changed in each version, refer to the Node and Python release notes.
The Python package installs provider and framework support as extras, so you only install what you use:
| Extra | Installs support for |
|---|---|
openai, azure | OpenAI and Azure OpenAI |
anthropic | Anthropic |
gemini | Google Gen AI (google-genai) |
bedrock | Amazon Bedrock (boto3) |
mistral | Mistral |
langchain, llamaindex, openai-agents, crewai | The matching framework integration |
fastapi | The FastAPI and Starlette middleware |
otel | OpenTelemetry export |
tokens | Local token counting (tiktoken) |
mcp | The SDK's MCP server |
all | Every extra in this table |
python3 -m pip install "amplitude-ai[openai,fastapi]"
In Node, install the provider package you use, such as openai or @anthropic-ai/sdk, next to @amplitude/ai. Provider packages are optional peer dependencies.
Initialize the SDK
Initialize once at your application entry point and reuse the instance. The recommended pattern is a bootstrap module that exports ai plus wrapped provider clients.
// src/lib/amplitude.ts
import { AmplitudeAI, AIConfig, OpenAI } from "@amplitude/ai";
export const ai = new AmplitudeAI({
apiKey: process.env.AMPLITUDE_AI_API_KEY!,
config: new AIConfig({ contentMode: "full", redactPii: true }),
});
export const openai = new OpenAI({
apiKey: process.env.OPENAI_API_KEY!,
amplitude: ai,
});
Import openai from this module instead of directly from 'openai'. Add more wrapped providers as needed.
To validate events during development without sending them, set dryRun: true (Node) or dry_run=True (Python) on AIConfig. To inspect the sanitized upload body, use review mode.
Configure the SDK
Pass an AIConfig to the AmplitudeAI constructor. All options are optional; the defaults work for most apps.
| Option | Description |
|---|---|
contentMode | 'full' (default), 'metadata_only', or 'customer_enriched'. Controls what message content reaches Amplitude. Refer to Choose a privacy mode. |
redactPii | Scrub emails, phone numbers, SSNs, credit card numbers, and IP addresses from tracked content before events leave the process. Defaults to true. Set to false to opt out. |
customRedactionPatterns | Additional redaction patterns. Accepts regex strings (replaced with [REDACTED]) or { pattern, replacement } objects for named labels. |
customRedactionFn | A (text) => string callback for custom redaction logic (for example, an NER library). Runs after all regex-based redaction. |
debug | Log every tracked event to stderr. |
dryRun | Build and log events without sending them to Amplitude. Use during development. |
reviewMode | Record each post-redaction event and print a sanitized upload preview without sending it. Defaults to false. Refer to Review outbound traffic. |
validate | Enforce strict validation of required fields. |
onEventCallback | A (event, statusCode, message) => void callback invoked exactly once per tracked event, from the delivery path. |
propagateContext | Enable cross-service context propagation. Refer to Propagate context across services. |
strictCost | Throw CostCalculationError when a response has tokens but the SDK can't calculate its cost. Use in development and CI to catch unpriced model names. Defaults to false. |
captureStackTrace | Attach error.stack to error events as [Agent] Stack Trace. Stack traces can contain file paths and internal details, so this defaults to false. |
For redaction recipes (named replacements, custom scrubbers, international locales), refer to Choose a privacy mode.
Instrument an agent session
Wrap each agent invocation in a session. The session correlates every event (user message, model response, tool calls, spans) into a single record.
An agent session is one job the user hands the agent, from start to finish. Set the sessionId from an ID you already track, such as a conversation thread, ticket, call, or run ID, rather than inventing a new one. Refer to Choose a session ID.
import { ai, openai } from "@/lib/amplitude";
const agent = ai.agent("chat-handler", {
description: "Customer support chatbot",
});
export async function POST(req: Request) {
const { messages, userId } = await req.json();
return agent.session({ userId }).run(async (s) => {
s.trackUserMessage(messages[messages.length - 1].content);
const response = await openai.chat.completions.create({
model: "gpt-4o-mini",
messages,
});
return Response.json(response);
});
}
A session opened with run() (Node) or the session() context manager (Python) closes when the scope exits. For sessions that span multiple requests, call trackSessionEnd() (Node) or track_session_end() (Python) when the job finishes, or let the idle timeout close it. Refer to How sessions close and Configure session timeouts.
Minimum viable instrumentation
Agent Analytics needs four fields to correlate events: the API key, a user identifier (userId or deviceId), an agentId, and a sessionId. The recommended pattern automatically adds provider wrappers so the SDK captures model, token, cost, and latency data.
For the user ID rules that keep one person from splitting into two users, refer to Set user IDs.
Auto-instrument provider calls
The SDK offers two zero-code paths for capturing provider activity.
Provider wrappers
Wrap the provider client at construction time. The wrapper forwards calls to the underlying client and records request, response, tokens, latency, and cost. Import the wrapper classes from the AI SDK, not from the provider package.
import { OpenAI } from "@amplitude/ai";
const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY!, amplitude: ai });
| Provider | Wrapper |
|---|---|
| OpenAI (Chat Completions + Responses) | new OpenAI({ apiKey, amplitude: ai }) |
| Anthropic | new Anthropic({ apiKey, amplitude: ai }) |
| Azure OpenAI | new AzureOpenAI({ apiKey, amplitude: ai }) |
Gemini (@google/generative-ai) | new Gemini({ apiKey, amplitude: ai }) |
Google Gen AI (@google/genai) | new GoogleGenAI({ apiKey, amplitude: ai }) |
| Bedrock (Converse APIs) | new Bedrock({ amplitude: ai, client }) |
| Mistral | new Mistral({ apiKey, amplitude: ai }) |
If you can't change the construction site, use wrap(existingClient, ai) (Node) or wrap(existing_client, amplitude=ai) (Python) to instrument an existing client without modifying its creation.
Coverage varies by provider. All wrappers capture streaming, system prompts, and cost; the rest depends on what the provider's API exposes:
| Feature | OpenAI | Anthropic | Gemini | Azure OpenAI | Bedrock | Mistral |
|---|---|---|---|---|---|---|
| Streaming | Yes | Yes | Yes | Yes | Yes | Yes |
| Tool-call tracking | Yes | Yes | No | Yes | Yes | No |
| TTFB measurement | Yes | Yes | No | Yes | No | No |
| Cache token stats | Yes | Yes | Yes | Yes | Yes | No |
| Responses API | Yes | — | — | — | — | — |
| Reasoning content | Yes | Yes | No | Yes | No | No |
| Cost estimation | Yes | Yes | Yes | Yes | Yes | Yes |
Bedrock model IDs such as us.anthropic.claude-3-5-sonnet are normalized for price lookup automatically.
patch()
Call patch({ amplitudeAI: ai }) once at startup for zero-code instrumentation. The SDK monkey-patches supported clients and auto-extracts [Agent] Tool Call events from message arrays for OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages. Extracted tool calls land with latencyMs: 0 because execution timing isn't available through message inspection. Use tool() or trackToolCall() when you need real tool latency.
patch() requires an active session context. Patched calls that fire outside a session context are silently dropped: no event is emitted, no error is thrown, and the provider call itself is unaffected. This includes AMPLITUDE_AI_AUTO_PATCH=true with amplitude-ai-instrument, which patches at process start but establishes no ambient session. This is the most common cause of "I instrumented but see no events." To verify a patched setup, wrap one call in a session:
const ai = new AmplitudeAI({ apiKey: process.env.AMPLITUDE_AI_API_KEY! });
patch({ amplitudeAI: ai });
const agent = ai.agent("verify", { userId: "verify-user-1" });
await agent.session().run(async () => {
await openai.chat.completions.create({
model: "gpt-4o",
messages: [{ role: "user", content: "Hello" }],
});
}); // one [Agent] AI Response
For request-scoped work, the Express middleware establishes the session context automatically (refer to Framework notes).
Track tools
The tool() higher-order function wraps a tool function so the SDK records each call:
import { tool } from "@amplitude/ai";
const searchProducts = tool(searchDB, { name: "search_products" });
// Inside session.run, call as usual:
const result = await searchProducts(query);
// [Agent] Tool Call event emitted with duration, success, input/output
For inline tool calls or unsupported flows, use s.trackToolCall(name, latencyMs, success, { input, output }) directly.
Tool content comes from the input and output options. Amplitude ignores other spellings without an error, so the span records that a tool ran but not what it did. That includes toolInput and toolOutput, which are the names of the resulting [Agent] Tool Input and [Agent] Tool Output properties. Tool calls that patch() extracts automatically carry no input or output either, so add an explicit trackToolCall when you need the content. Rendering agent visuals in the session view depends on it. Refer to Render agent artifacts.
For scripts and notebooks, ToolCallTracker.setAmplitude() (Node) or ToolCallTracker.set_amplitude() (Python) sets a process-wide default for tool tracking outside a session. The setting is global, so don't use it in multi-tenant servers; open a session per request instead.
tool() and @tool capture input and output according to the active privacy config: the one passed to the decorator, then the session's AmplitudeAI client, then ToolCallTracker. When none is set, the SDK records metadata only, and the Python SDK logs a one-time warning that starts with @tool: no privacy config found. To capture content, pass privacyConfig (Node) or privacy_config= (Python), or run the tool inside a session.
Track spans
Spans wrap internal sub-operations such as vector lookups, reranks, guardrails, or any timed work that sits inside a turn. They emit [Agent] Span events and share the trace's identity.
OTEL-enabled behavior
When OTEL is enabled through enable_otel() / enableOtel(), observe() / @observe creates real OTEL spans instead of emitting events directly. The SpanEventMapper converts these spans into the appropriate [Agent] event type. Use the type parameter to control routing: @observe(type="tool") routes the span as [Agent] Tool Call rather than [Agent] Span.
import { observe } from "@amplitude/ai";
// As a higher-order function:
const runSubAgent = observe(
async (prompt: string) => {
return await subAgent.execute(prompt);
},
{ name: "sub-agent-execution" },
);
// Or explicitly when you need error capture:
const start = Date.now();
try {
const result = await subAgent.execute(prompt);
s.trackSpan({
name: "sub-agent-execution",
latencyMs: Date.now() - start,
inputState: { prompt: prompt.slice(0, 1000) },
outputState: { response: result.slice(0, 1000) },
});
} catch (e) {
s.trackSpan({
name: "sub-agent-execution",
latencyMs: Date.now() - start,
isError: true,
errorType: (e as Error).name,
errorMessage: (e as Error).message,
});
throw e;
}
Spans don't replace turn-level events
Agent Analytics turn counts and interaction views are driven by [Agent] User Message and [Agent] AI Response, not spans. If you only emit spans around internal steps, dashboards show traces with no turn-level analytics. Always emit the User Message / AI Response pair for each user-visible cycle, and use spans on top.
Track embeddings
For retrieval and RAG workloads, track each embedding call as an [Agent] Embedding event with its model, provider, latency, and optionally input tokens, dimensions, and cost. Call the provider's embeddings API with your regular client, then track the call. The LlamaIndex and OpenTelemetry integrations track embeddings for you.
import OpenAIClient from "openai";
const embedder = new OpenAIClient();
const start = Date.now();
const result = await embedder.embeddings.create({ model: "text-embedding-3-small", input: query });
s.trackEmbedding("text-embedding-3-small", "openai", Date.now() - start, {
inputTokens: result.usage.prompt_tokens,
dimensions: result.data[0].embedding.length,
});
When you pass input tokens, the SDK calculates [Agent] Cost USD for you. To set the cost yourself, pass totalCostUsd (Node) or total_cost_usd (Python).
Manual instrumentation
For custom flows or unsupported providers, use the manual methods on the session object directly. Each maps to a single [Agent] event type.
| Method | Event | Use when |
|---|---|---|
s.trackUserMessage(text) | [Agent] User Message | User-authored input arrives |
s.trackAiMessage(text, model, provider, latencyMs, opts?) | [Agent] AI Response | Provider wrapper can't auto-capture |
s.trackToolCall(name, latencyMs, success, opts?) | [Agent] Tool Call | Calling a tool outside tool(). Content comes from opts.input / opts.output |
s.trackSpan({ name, latencyMs, ... }) | [Agent] Span | Wrapping an internal sub-step |
s.runAs(childAgent, fn) | (delegation) | Routing to a child agent |
For AI responses that don't go through a wrapper (proxies, custom gateways), pass usage from the completion response:
s.trackAiMessage(completedMessage.content, "gpt-4o", "openai", latencyMs, {
inputTokens: usage.prompt_tokens,
outputTokens: usage.completion_tokens,
totalTokens: usage.total_tokens,
});
Pass the canonical provider model id (gpt-4o-mini, claude-sonnet-4-20250514), not an internal gateway label, so cost auto-calculates correctly.
Add segmentation with context
Pass a context dictionary to ai.agent(...) to attach arbitrary segmentation dimensions to every event. The SDK serializes it to [Agent] Context, so you can segment AI sessions without registering new global properties.
const agent = ai.agent("support-bot", {
context: {
agent_type: "executor",
experiment_variant: "reasoning-enabled",
surface: "chat",
},
});
These keys cover the most common segmentation needs:
| Key | Example values | Use case |
|---|---|---|
agent_type | "planner", "executor", "retriever", "router" | Group analytics by agent role in multi-agent systems. |
experiment_variant | "control", "treatment-v2" | Compare quality, abandonment, or cost across A/B test arms. |
feature_flag | "new-rag-pipeline" | Track which flags were active during the session. |
surface | "chat", "search", "copilot" | Identify the UI surface that triggered the interaction. |
prompt_revision | "v7", "2026-02-15" | Track the prompt version; detect regressions alongside agentVersion. |
deployment_region | "us-east-1", "eu-west-1" | Segment by region for latency or compliance analysis. |
canary_group | "canary", "stable" | Separate canary from stable deployments during a rollout. |
Tag sessions
Pass tags when you open a session to label every event in it, for example by feature or cohort. The SDK emits them as [Agent] Tags on each event in the session.
await agent.session({ userId, sessionId, tags: ["beta", "checkout"] }).run(async (s) => {
// ...
});
Use context for key-value dimensions and tags for simple labels.
Merge context across child agents
Child agents inherit the parent's context. Keys on the child override matching parent keys; parent keys the child doesn't set are preserved.
const parent = ai.agent("orchestrator", {
context: { experiment_variant: "treatment", surface: "chat" },
});
const child = parent.child("researcher", {
context: { agent_type: "retriever" },
});
// child context = { experiment_variant: "treatment", surface: "chat", agent_type: "retriever" }
Query context in Amplitude
[Agent] Context is a JSON string. To query individual keys:
- Derived properties: For frequently-used keys, create a derived event property (Data > Properties > Derived > New) that extracts the value permanently.
- Filters: Use
[Agent] Context contains "key":"value"for string matching in chart filters.
Use multiple tenants
On a multi-tenant platform, create a tenant-scoped handle with ai.tenant(orgId, opts?) (Node) or ai.tenant(org_id, ...) (Python). Every agent created from the handle pre-binds customerOrgId, which lands as [Agent] Customer Org ID on each event, so you can segment usage by end customer without threading the org ID through every call.
const tenant = ai.tenant("org-456", { env: "production" });
const agent = tenant.agent("support-bot", { userId: "user-123" });
// agent.track* calls carry [Agent] Customer Org ID = "org-456"
Classify model tiers
The SDK infers a model tier from the model name and attaches it as [Agent] Model Tier on every [Agent] AI Response. Tiers let you compare cost and performance across model classes without listing every model.
| Tier | Examples | When to use |
|---|---|---|
fast | gpt-4o-mini, claude-3-haiku, gemini-flash, gpt-3.5-turbo | High-volume, latency-sensitive work. |
standard | gpt-4o, claude-3.5-sonnet, gemini-pro, llama, command | General purpose. |
reasoning | o1, o3-mini, deepseek-r1, Claude with extended thinking | Complex reasoning tasks. |
Call inferModelTier() / infer_model_tier() to resolve a tier directly:
import { inferModelTier } from "@amplitude/ai";
inferModelTier("gpt-4o-mini"); // 'fast'
inferModelTier("claude-3.5-sonnet"); // 'standard'
inferModelTier("o1-preview"); // 'reasoning'
For custom or fine-tuned models the name can't classify, pass modelTier / model_tier on the AI-message call to override the inferred value:
s.trackAiMessage(response.content, "ft:gpt-4o:my-org:custom", "openai", latencyMs, {
modelTier: "standard",
});
Track attachments
Pass an attachments array to the user-message call to record files sent with a message (images, PDFs, URLs). Each entry carries type, name, and size_bytes.
s.trackUserMessage("Analyze this document", {
attachments: [
{ type: "image", name: "chart.png", size_bytes: 102400 },
{ type: "pdf", name: "report.pdf", size_bytes: 2048576 },
],
});
The SDK derives these properties from the array, recording attachment metadata only, never file content: [Agent] Has Attachments, [Agent] Attachment Types, [Agent] Attachment Count, [Agent] Total Attachment Size Bytes, and [Agent] Attachments. Attachments also apply to AI responses, such as model-generated images. Pass the same attachments option to the AI-message call.
Capture implicit feedback
Behavioral signals indicate whether a response met the user's need without requiring an explicit rating. Set these options on the relevant track calls; the SDK maps them to queryable quality properties.
| Signal | Property | Interpretation |
|---|---|---|
| Copy | [Agent] Was Copied | User copied the output, a positive signal. Set on the AI-message call. |
| Regeneration | [Agent] Is Regeneration | User asked for a redo, a negative signal. Set on the user-message call. |
| Edit | [Agent] Is Edit + [Agent] Edited Message ID | User refined a previous prompt, a friction signal. Set on the user-message call. |
| Abandonment | [Agent] Abandonment Turn | User left after N turns; a low value (such as 1) signals first-response dissatisfaction. Set on session end. |
// AI response the user copied (positive)
s.trackAiMessage("To create a funnel, go to...", "gpt-4o", "openai", latencyMs, { wasCopied: true });
// User regenerates (negative — first response fell short)
s.trackUserMessage("How do I create a funnel?", { isRegeneration: true });
// User edits and resubmits their prompt
s.trackUserMessage("How do I create a conversion funnel for signups?", {
isEdit: true,
editedMessageId: originalMsgId,
});
// User left after the first AI response
agent.trackSessionEnd({ sessionId: "sess-1", abandonmentTurn: 1 });
Import existing conversations
To backfill a full message history in one call, use trackConversation() (Node) or track_conversation() (Python). Pass an array of { role, content } messages; each becomes a [Agent] User Message or [Agent] AI Response, with turn IDs auto-incremented in order. system messages are skipped.
import { trackConversation } from "@amplitude/ai";
import * as amplitude from "@amplitude/analytics-node";
trackConversation({
amplitude,
userId: "user-123",
sessionId: "sess-abc",
agentId: "support-bot",
messages: [
{ role: "user", content: "How do I reset my password?" },
{
role: "assistant",
content: "Go to Settings > Security > Reset Password.",
model: "gpt-4o",
provider: "openai",
latency_ms: 1200,
input_tokens: 15,
output_tokens: 42,
},
{ role: "user", content: "Thanks, that worked!" },
],
});
Use this to import historical conversations or migrate data from external systems. The function accepts the same context fields as the individual tracking methods.
Send user feedback (scores)
Capture explicit user feedback, such as a thumbs up or down on a response or an optional rating, as a [Agent] Score event. Scores come only from your application; Amplitude's enrichment pipeline never generates them. Call ai.score() any time, including after the session closes, because it targets a message or session by ID rather than the active session.
// Thumbs up/down on a specific AI response
ai.score({
userId: "user-123",
name: "user-feedback",
value: 1.0,
targetId: aiMessageId,
targetType: "message",
source: "user",
});
Use the name user-feedback for your binary thumbs control. A thumbs down sent this way counts as explicit dissatisfaction for the Negative Feedback signal. For the full pattern (in-session and post-request paths, CSAT scales), refer to the Collect user feedback in Agent Analytics.
If you ingest events directly instead of using the SDK, send an [Agent] Score event with [Agent] Score Name set to your score name (for example, user-feedback).
Multi-agent architectures
Parent agents can delegate to child agents. Child agents inherit the parent's session, so all events stay correlated under one Session ID.
const orchestrator = ai.agent('shopping-agent', { description: 'Orchestrates shopping requests' });
const recipeAgent = orchestrator.child('recipe-agent', { description: 'Finds recipes' });
await orchestrator.session({ userId }).run(async (s) => {
s.trackUserMessage(userInput);
const result = await s.runAs(recipeAgent, async (cs) => {
cs.trackUserMessage(delegatedQuery);
return openai.chat.completions.create({ model: 'gpt-4o', messages: [...] });
});
});
Wrap delegation calls with observe() or trackSpan if you want latency and error metrics on the dispatch itself, not only the child's LLM call.
Integration patterns
Single-request API endpoint
For a serverless function or one-shot endpoint, create the session inside the handler and flush before returning so the runtime doesn't freeze before events ship.
app.post("/chat", async (req, res) => {
const agent = ai.agent("api-handler", { userId: req.userId });
const result = await agent.session({ sessionId: req.sessionId }).run(async (s) => {
s.trackUserMessage(req.body.message);
const start = performance.now();
const response = await openai.chat.completions.create({
model: "gpt-4o",
messages: req.body.messages,
});
s.trackAiMessage(
response.choices[0].message.content ?? "",
"gpt-4o",
"openai",
performance.now() - start,
{
inputTokens: response.usage?.prompt_tokens,
outputTokens: response.usage?.completion_tokens,
},
);
return response.choices[0].message.content;
});
await ai.flush();
res.json({ response: result });
});
Long-lived session (chatbot)
For a multi-turn conversation, create the session once and reuse it across turns. Track a user/AI pair per turn; the session ends when run() returns or the idle timeout fires.
const agent = ai.agent("chatbot", { userId: "user-123", env: "production" });
await agent.session({ sessionId: conversationId }).run(async (s) => {
s.trackUserMessage("What is Amplitude?");
const r1 = await llm.chat("What is Amplitude?");
s.trackAiMessage(r1.content, "gpt-4o", "openai", r1.latencyMs, {
inputTokens: r1.usage.input,
outputTokens: r1.usage.output,
});
s.trackUserMessage("How does it track events?");
const r2 = await llm.chat("How does it track events?");
s.trackAiMessage(r2.content, "gpt-4o", "openai", r2.latencyMs, {
inputTokens: r2.usage.input,
outputTokens: r2.usage.output,
});
});
Multi-agent orchestration
When a parent agent delegates to specialized children, wrap each delegation in runAs() / arun_as(). Both manual tracking calls and provider wrappers inside the callback pick up the child's identity automatically. For the basic delegation shape, refer to Multi-agent architectures.
How runAs / arun_as works:
- Shares the parent session's
sessionId,traceId, and turn counter. - Sets
agentIdto the child andparentAgentIdto the parent for the callback's duration. - Suppresses auto user-message tracking, so internal
role: "user"prompts in delegation calls don't create spurious user turns. - Doesn't emit
[Agent] Session End; the child runs inside the parent session, which emits one session end. - Restores the parent context when the callback completes, even on error.
- Supports nesting: a child can
runAsa grandchild.
Fan-out (parallel child calls, single user turn)
When one user turn triggers several parallel LLM calls, open a fresh trace with newTrace() / new_trace(), dispatch the children with Promise.all (Node) or asyncio.gather (Python), and emit a single AI response after they join. This keeps one trace, one user turn, and one AI response regardless of how many internal calls run.
await orchestrator.session({ sessionId }).run(async (s) => {
s.newTrace();
s.trackUserMessage("Generate plan from quiz results", { context: structuredState });
const [a, b] = await Promise.all([
s.runAs(scorer, () =>
openai.chat.completions.create({ model: "gpt-4o", messages: scorerMessages }),
),
s.runAs(matcher, () =>
openai.chat.completions.create({ model: "gpt-4o", messages: matcherMessages }),
),
]);
s.trackAiMessage(assemble(a, b), "gpt-4o", "openai", totalLatencyMs);
});
Stream responses
Streaming sessions must stay open until the stream is fully consumed. Closing the session before the stream finishes drops the AI response event.
// WRONG: session ends before stream is consumed
return agent.session({ userId }).run(async (s) => {
const stream = await openai.chat.completions.create({
model: "gpt-4o",
messages,
stream: true,
});
return new Response(stream.toReadableStream());
});
// CORRECT: session stays open until stream completes
return agent.session({ userId }).run(async (s) => {
const stream = await openai.chat.completions.create({
model: "gpt-4o",
messages,
stream: true,
});
const readable = stream.toReadableStream();
const [passthrough, forClient] = readable.tee();
const reader = passthrough.getReader();
(async () => {
while (!(await reader.read()).done) {}
})();
return new Response(forClient);
});
In Python, consume the stream inside the session block. For a streaming HTTP response, open the session inside the generator, so it stays open until your app sends the last chunk:
from fastapi.responses import StreamingResponse
def stream_answer(user_id: str, session_id: str, messages: list):
with agent.session(user_id=user_id, session_id=session_id):
stream = openai.chat.completions.create(model="gpt-4o", messages=messages, stream=True)
for chunk in stream:
if chunk.choices and chunk.choices[0].delta.content:
yield chunk.choices[0].delta.content
@app.post("/chat")
def chat(body: ChatRequest):
return StreamingResponse(stream_answer(body.user_id, body.session_id, body.messages))
With the Vercel AI SDK, flush in the onFinish callback:
const result = await streamText({
model: openai("gpt-4o"),
messages,
onFinish: async () => {
await ai.flush();
},
});
If you stream from a provider the SDK doesn't wrap, collect the stream with StreamingAccumulator, imported from @amplitude/ai in Node and amplitude_ai.utils in Python, and track one AI response when it ends. Add each text chunk with addContent() (Node) or add_content() (Python), which also measures time to first byte, record token usage from the final chunk, then pass the collected content and tokens to trackAiMessage() / track_ai_message().
Link to the standard-analytics session
When a session crosses the network boundary, pass Amplitude IDs through request headers so server-side events join the user's standard-analytics session ($session_id). Pass the value as the session's browserSessionId field:
const browserSessionId = req.headers.get("x-amplitude-session-id");
const deviceId = req.headers.get("x-amplitude-device-id");
const session = agent.session({ userId, browserSessionId, deviceId });
For cross-service propagation between back-end services, use injectContext() on the outbound side and extractContext(headers) on the inbound side.
Propagate context across services
When one back-end service calls another, propagate the active identity and session so the downstream events join the same trace instead of starting a new one. On the outbound side, injectContext() serializes the active context (session ID, trace ID, user ID) into request headers. On the inbound side, extractContext(headers) reads them back.
// --- Service A (outbound) ---
import { injectContext } from "@amplitude/ai";
await agent.session({ userId, sessionId }).run(async (s) => {
s.trackUserMessage(message);
const headers = injectContext({ "content-type": "application/json" });
await fetch("https://service-b/internal/enrich", {
method: "POST",
headers,
body: JSON.stringify({ message }),
});
});
// --- Service B (inbound) ---
import { randomUUID } from "node:crypto";
import { extractContext, runWithContextAsync, SessionContext } from "@amplitude/ai";
export async function POST(req: Request) {
const extracted = extractContext(Object.fromEntries(req.headers));
const ctx = new SessionContext({
sessionId: extracted.sessionId ?? randomUUID(),
traceId: extracted.traceId ?? null,
userId: extracted.userId ?? null,
});
return runWithContextAsync(ctx, async () => {
await handleEnrichment(req);
});
}
injectContext() returns a new headers object and never mutates the original. If no session is active, it returns the headers unchanged, so it's safe to call unconditionally.
Supported providers and frameworks
Providers with native wrappers: OpenAI (Chat Completions + Responses), Anthropic, Azure OpenAI, Gemini (@google/generative-ai), Google Gen AI (@google/genai), Mistral, Bedrock (Converse APIs).
Agent frameworks with first-party integrations: LangChain, LlamaIndex, OpenAI Agents SDK, Anthropic Tool Use, Claude Agent SDK (ClaudeAgentSDKTracker), Anthropic Managed Agents, CrewAI (Python only).
Framework integrations
The integrations below bridge an agent framework's own callback or tracing system into Agent Analytics. Each takes the ai instance, or ai.amplitude for CrewAI, plus identity fields, then hooks into the framework. CrewAI is Python-only; in Node, AmplitudeCrewAIHooks throws by design. Use the LangChain or OpenTelemetry path instead.
LangChain
Pass an AmplitudeCallbackHandler to LangChain's callbacks.
import { AmplitudeCallbackHandler } from "@amplitude/ai";
const handler = new AmplitudeCallbackHandler({ amplitudeAI: ai, userId: "user-123", sessionId: "sess-1" });
// Pass handler to any LangChain runnable via { callbacks: [handler] }
LlamaIndex
import { AmplitudeLlamaIndexHandler } from "@amplitude/ai";
const handler = new AmplitudeLlamaIndexHandler({ amplitudeAI: ai, userId: "user-123", sessionId: "sess-1" });
OpenAI Agents SDK
Register an AmplitudeTracingProcessor as a tracing processor.
import { AmplitudeTracingProcessor } from "@amplitude/ai";
const processor = new AmplitudeTracingProcessor({ amplitudeAI: ai, userId: "user-123", sessionId: "sess-1" });
// Register with the OpenAI Agents SDK trace provider.
Anthropic Tool Use
AmplitudeToolLoop runs Anthropic's multi-turn tool_use loop and tracks each AI response and tool call.
import { AmplitudeToolLoop } from "@amplitude/ai";
const loop = new AmplitudeToolLoop({ amplitudeAI: ai, userId: "user-123", sessionId: "sess-1" });
await loop.run({ client, model: "claude-sonnet-4-20250514", messages, tools, toolExecutor });
CrewAI (Python)
AmplitudeCrewAIHooks registers CrewAI hooks for LLM calls and tool calls. Pass it the underlying Amplitude client, ai.amplitude. Activate it before the crew runs and deactivate it afterward.
from amplitude_ai.integrations.crewai import AmplitudeCrewAIHooks
hooks = AmplitudeCrewAIHooks(amplitude=ai.amplitude, user_id="user-123")
hooks.activate()
result = crew.kickoff()
hooks.deactivate()
OpenTelemetry attribute mapping
If a framework already emits OpenTelemetry GenAI spans, the SDK maps them onto [Agent] properties. For how to enable this, including the span-first enableOtel() / enable_otel() path and the manual AmplitudeGenAIExporter / AmplitudeAgentExporter exporters, refer to Ingest OpenTelemetry spans. The mapping the exporter applies:
| OTEL span attribute | [Agent] property | Notes |
|---|---|---|
gen_ai.response.model / gen_ai.request.model | [Agent] Model Name | Response model preferred. |
gen_ai.system / gen_ai.provider.name | [Agent] Provider | Required; spans without it are ignored. |
gen_ai.usage.input_tokens | [Agent] Input Tokens | |
gen_ai.usage.output_tokens | [Agent] Output Tokens | |
gen_ai.usage.total_tokens | [Agent] Total Tokens | Derived from input + output if absent. |
gen_ai.request.temperature | [Agent] Temperature | |
gen_ai.request.top_p | [Agent] Top P | |
gen_ai.request.max_tokens | [Agent] Max Output Tokens | |
gen_ai.response.finish_reasons | [Agent] Finish Reason | First reason if an array. |
gen_ai.tool.name | [Agent] Tool Name | Routes the span as [Agent] Tool Call. |
gen_ai.input.messages | $llm_message | User-role messages only, and only if the privacy mode allows. |
| Span duration | [Agent] Latency Ms | |
Span status ERROR | [Agent] Is Error, [Agent] Error Message |
Some signals have no OTEL equivalent and require the native provider wrappers: reasoning content and tokens, TTFB, streaming detection, implicit feedback, file attachments, and event-graph linking through [Agent] Parent Message ID. You can run OTEL and a native wrapper together for the same call. The SDK de-duplicates, so no double events emit.
Provider-specific notes
Vercel AI SDK
Provider wrappers instrument the underlying SDK (openai), not the Vercel abstraction. If only @ai-sdk/openai is present, either add openai as a direct dependency or fall back to patch(). For streaming responses, use onFinish to call await ai.flush() (refer to Stream responses).
Claude Agent SDK
Use ClaudeAgentSDKTracker from @amplitude/ai/integrations/claude-agent-sdk. Two fields are required for the events to be useful: agentId on ai.agent() (identifies the AI feature in the LLM Usage Application Registry), and userId + sessionId on agent.session() (ties events into a single interaction).
import { AmplitudeAI } from "@amplitude/ai";
import { ClaudeAgentSDKTracker } from "@amplitude/ai/integrations/claude-agent-sdk";
import { query } from "@anthropic-ai/claude-agent-sdk";
const ai = new AmplitudeAI({ apiKey: process.env.AMPLITUDE_AI_API_KEY! });
const agent = ai.agent({ agentId: "code-reviewer" });
const tracker = new ClaudeAgentSDKTracker();
await agent.session({ userId: "u1", sessionId: "sess-abc" }).run(async (s) => {
for await (const message of query({
prompt: "Analyze this codebase",
options: { hooks: tracker.hooks(s) },
})) {
tracker.process(s, message);
}
});
In Python, import the same tracker from amplitude_ai.integrations.claude_agent_sdk:
from amplitude_ai.integrations.claude_agent_sdk import ClaudeAgentSDKTracker
from claude_agent_sdk import ClaudeAgentOptions, query
agent = ai.agent("code-reviewer")
tracker = ClaudeAgentSDKTracker()
async with agent.session(user_id="u1", session_id="sess-abc") as s:
options = ClaudeAgentOptions(hooks=tracker.hooks(s))
async for message in query(prompt="Analyze this codebase", options=options):
tracker.process(s, message)
tracker.hooks(session) returns PreToolUse / PostToolUse hooks with precise tool latency. tracker.process(session, message) processes the message stream for AI responses and user messages.
Anthropic Managed Agents
Provider wrappers don't work, because LLM calls happen in Anthropic's cloud, not your code. Use manual tracking and poll client.beta.sessions.events.list(). Map event types to SDK methods:
| Anthropic event | SDK call |
|---|---|
user.message | trackUserMessage(text) (track when sending, not when polling) |
agent.message | trackAiMessage(text, model, 'anthropic', latencyMs) |
agent.tool_use / agent.mcp_tool_use / agent.custom_tool_use | trackToolCall(name, latencyMs, success) |
agent.tool_result / agent.mcp_tool_result | skip (latency captured at tool_use time) |
session.error | trackAiMessage(errorMsg, model, 'anthropic', latencyMs, { isError: true }) |
Deduplicate events across polls, because events.list() returns previously-seen events:
const seenIds = new Set<string>(savedState.seenIds);
for (const event of response.data) {
if (seenIds.has(event.id)) continue;
seenIds.add(event.id);
// track event
}
Measure latency as wall-clock time between session.status_running and the event's processed_at, not poll round-trip. events.list() doesn't include usage or token counts, so cost tracking requires the Anthropic Admin API.
OpenAI Assistants API
Provider wrappers don't auto-instrument the Assistants API (async / polling-based). Use manual tracking: trackUserMessage() when creating a message, trackAiMessage() when polling completion events.
Instrument your own MCP server
This section covers tracking tool calls inside an MCP server you build. For the MCP server that ships with the AI SDK and helps coding agents instrument your app, refer to amplitude-ai mcp in Auto-instrument and CLI tools.
The MCP protocol doesn't pass the originating user prompt to tools, so MCP servers can't capture it. Add an optional rationale parameter to each tool so the LLM can self-explain its intent and you keep usable session content.
Framework notes
Next.js (App Router)
Initialize the SDK in a server-side module, never a client component. Add @amplitude/ai to serverExternalPackages in next.config.ts. Wrap session creation inside each route handler; in serverless deployments call await ai.flush() before the handler returns so the runtime doesn't freeze before events ship.
Express, Fastify, Hono, FastAPI, and Starlette
Use the bundled middleware to open a session for every request. Provider wrappers and tool calls inside the request handler inherit that session. The Node middleware supports Express, Fastify, and Hono. The Python middleware is ASGI middleware for FastAPI and Starlette; it ends the session and flushes events after each response.
import { createAmplitudeAIMiddleware } from "@amplitude/ai";
app.use(
createAmplitudeAIMiddleware({
amplitudeAI: ai,
userIdResolver: (req) => req.user?.id ?? null, // authenticated user, not a request header
}),
);
For Flask, Django, and other WSGI frameworks, open a session in each request handler with ai.agent(...).session(...) instead.
Edge runtimes and Cloudflare Workers
@amplitude/ai cannot bundle in Cloudflare Workers. The SDK depends on node:async_hooks, node:module, and node:crypto. Workers Builds rejects the upload even with nodejs_compat_v2 enabled. @amplitude/analytics-node is also incompatible (depends on Node's http).
The only safe import is import type { ... } from '@amplitude/ai/types', which is erased at compile time. For runtime tracking, use a fetch-based transport that constructs [Agent] events directly:
import type { AmplitudeClientLike, AmplitudeEvent } from "@amplitude/ai/types";
class FetchAmplitudeClient implements AmplitudeClientLike {
private _apiKey: string;
private _buffer: AmplitudeEvent[] = [];
constructor(apiKey: string) {
this._apiKey = apiKey;
}
track(event: AmplitudeEvent): void {
this._buffer.push(event);
}
async flush(): Promise<void> {
if (!this._buffer.length) return;
const events = this._buffer.splice(0);
try {
const resp = await fetch("https://api2.amplitude.com/2/httpapi", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({ api_key: this._apiKey, events }),
});
if (!resp.ok) console.error(`[Amplitude] Flush failed: ${resp.status}`);
} catch (err) {
console.error(`[Amplitude] Flush error: ${(err as Error).message}`);
}
}
}
export default {
async fetch(request: Request, env: Env, ctx: ExecutionContext) {
if (env.AMPLITUDE_TRACKING_DISABLED) return handleRequest(request, env);
const transport = new FetchAmplitudeClient(env.AMPLITUDE_API_KEY);
transport.track({
event_type: "[Agent] User Message",
user_id: userId,
event_properties: {
"[Agent] Session ID": sessionId,
"[Agent] Agent ID": "my-agent",
$llm_message: { text: content },
},
});
// After the LLM call completes:
transport.track({
event_type: "[Agent] AI Response",
user_id: userId,
event_properties: {
"[Agent] Session ID": sessionId,
"[Agent] Agent ID": "my-agent",
"[Agent] Model Name": model,
"[Agent] Provider": "anthropic",
"[Agent] Latency Ms": latencyMs,
$llm_message: { text: responseText },
},
});
// Non-blocking flush so events ship before the isolate terminates
ctx.waitUntil(transport.flush());
return new Response("ok");
},
};
Construct FetchAmplitudeClient per-request to avoid buffer leakage between requests. Use crypto.randomUUID() for event insert_id dedup, and gate tracking behind an AMPLITUDE_TRACKING_DISABLED env var to disable it.
Run in serverless environments
The SDK auto-detects serverless platforms (Vercel, AWS Lambda, Netlify, Google Cloud Functions, Azure Functions, Cloudflare Pages) from their environment variables. When it detects one, session.run() flushes pending events before the promise resolves, so you don't need an explicit ai.flush(). In a long-running server, it skips the per-session flush and lets the analytics client batch normally.
Control this per session with the autoFlush option (Node) or auto_flush (Python). Leave it unset to use auto-detection, set it to true to always flush on session exit, or false to never flush.
If you track events outside session.run(), flush before the handler returns or the runtime can freeze the process with events still buffered.
ai.flush() and ai.shutdown() serve different lifecycles:
ai.flush()sends buffered events now and keeps the SDK running. Use it in serverless handlers and API endpoints to guarantee delivery before responding.ai.shutdown()flushes and then closes the underlying analytics client. Call it once on process exit, such as aSIGTERMhandler. It only closes the client when you created it throughapiKey; if you passed your own instance, you own its lifecycle.
process.on("SIGTERM", () => {
ai.shutdown();
process.exit(0);
});
Cloudflare Workers (edge isolates) aren't a supported serverless target; the full SDK can't bundle into a Worker. Refer to Edge runtimes and Cloudflare Workers for the fetch-based transport.
Ingest OpenTelemetry spans
The exporters below run in-process, inside a Node or Python app that already uses this SDK. If your spans already reach an OpenTelemetry Collector, you can skip the SDK entirely and point the Collector at Amplitude's OTLP endpoint instead. Refer to Send OpenTelemetry traces directly.
For stacks that already emit OpenTelemetry GenAI spans (OpenLIT, Traceloop, OpenAI's OTel instrumentation), map them into [Agent] events:
AmplitudeGenAIExporter(inbound, production-ready): ingests GenAI semantic-convention spans and emits[Agent]events. Ignores non-GenAI spans, so it's safe in a mixed pipeline.AmplitudeAgentExporter(outbound, experimental): converts Amplitude events into flat OTel spans for forwarding to other backends. Doesn't preserve trace hierarchy.
In Python, enable_otel() maps only spans that carry gen_ai.* or amplitude.* attributes. To also send other spans on the provider, such as HTTP or database spans, as [Agent] Span events, pass otel_span_filter="all". Span names from those instrumentations can contain user data, so review them before you turn this on.
ai = AmplitudeAI(api_key=os.environ["AMPLITUDE_AI_API_KEY"]).enable_otel(otel_span_filter="all")
Choose a privacy mode
Set contentMode (Node) or content_mode (Python) on AIConfig to full (default), metadata_only, or customer_enriched. For what each mode sends and how to choose, refer to Agent Analytics privacy modes.
Every content-emitting channel in the SDK routes through a single privacy gate, so the mode applies uniformly across direct SDK calls, provider wrappers, observe() spans, OTel exception recording, and any framework integrations. metadata_only gates these channels:
- Message text (
$llm_message.text) on User Message and AI Response - Tool inputs and outputs (
[Agent] Tool Input,[Agent] Tool Output) - System prompts (
[Agent] System Prompt) - Exception messages and stack traces recorded by
observe()and OTel span error paths - Framework-emitted content attributes such as
gen_ai.system_instructionsandgen_ai.input.messages/gen_ai.output.messages - Score comments (
[Agent] Comment)
In full mode, PII redaction scrubs emails, phone numbers, SSNs, credit card numbers, IP addresses, and base64-encoded image data before events leave the process. The SDK tunes phone and SSN detection for US formats; add customRedactionPatterns or customRedactionFn for international locales.
Redaction is on by default in both SDKs:
- Node:
redactPiidefaults totrue. - Python:
redact_piidefaults toTruefrom version 1.17.0. Earlier versions default toFalseonAIConfig, so upgrading to 1.17.0 starts scrubbing content that was sent raw before. To keep raw content, passAIConfig(redact_pii=False).
For managed-agent architectures, prefer full with redaction on. The managed API already stores message content server-side, so metadata_only adds no privacy benefit.
Provide your own session enrichments
In customer_enriched mode, the SDK sends no message text. You run your own evaluation pipeline and ship the results back as structured session-level enrichments. Use this when compliance requires zero-content transmission, or when your eval logic goes beyond Amplitude's built-in server-side enrichment.
Build a SessionEnrichments object and send it with trackSessionEnrichment() (Node) or track_session_enrichment() (Python). The enrichment lands as an [Agent] Session Enrichment event, serialized into the [Agent] Enrichments property; the same fields also attach to [Agent] Session End when you set enrichments before the session closes.
The substantive fields on a SessionEnrichments object:
| Field | Purpose |
|---|---|
qualityScore, sentimentScore | Numeric quality and sentiment of the session. |
overallOutcome | Terminal result, such as resolved or escalated. |
topicClassifications | Map of taxonomy name to a TopicClassification (topic, confidence, subcategories). |
rubricScores | Array of RubricScore (name, score, rationale, evidence). |
agentChain, rootAgentName | Agent topology for multi-agent runs. |
requestComplexity | Difficulty bucket, such as low, medium, or high. |
errorCategories | Categorized failure signals from your pipeline. |
messageLabels | Per-message labels keyed by the message ID returned from each tracking call. |
customMetadata | Arbitrary key/value data for your own analytics. |
import {
AmplitudeAI,
AIConfig,
ContentMode,
SessionEnrichments,
RubricScore,
TopicClassification,
} from "@amplitude/ai";
const ai = new AmplitudeAI({
apiKey: process.env.AMPLITUDE_AI_API_KEY!,
config: new AIConfig({ contentMode: ContentMode.CUSTOMER_ENRICHED }),
});
const agent = ai.agent("support-bot", { agentVersion: "2.1.0" });
// 1. Run the conversation — no content is sent, only metadata.
const { sessionId } = await agent.session({ userId: "user-42" }).run(async (s) => {
s.trackUserMessage("Why was I charged twice?");
s.trackAiMessage(aiResponse.content, "gpt-4o", "openai", latencyMs);
return { sessionId: s.sessionId };
});
// 2. Score the raw messages with your own pipeline.
const evalResults = await myEvalPipeline(conversationHistory);
// 3. Ship the enrichments back to Amplitude.
const enrichments = new SessionEnrichments({
qualityScore: evalResults.quality,
sentimentScore: evalResults.sentiment,
overallOutcome: evalResults.outcome,
topicClassifications: {
billing: new TopicClassification({ topic: "billing-dispute", confidence: 0.92 }),
},
rubricScores: [new RubricScore({ name: "accuracy", score: 4, maxScore: 5 })],
customMetadata: { eval_model: "gpt-4o-judge-v2" },
});
agent.trackSessionEnrichment(enrichments, { sessionId });
This produces the same event properties as Amplitude's built-in enrichment (topics, rubrics, outcomes, message labels), sourced from your pipeline instead.
Message labels
Message labels are key-value pairs attached to individual messages for filtering and segmentation, such as routing tags (flow, surface), classifier output (intent, sentiment), or business context (tier, plan). They emit as [Agent] Message Labels on the message event. Attach them two ways:
- Inline, at tracking time, by passing
labelstotrackUserMessage()/track_user_message(). - Retrospectively, when classifier results arrive after the session, through
SessionEnrichments.messageLabelskeyed by the message ID returned from each tracking call.
Manage cost and tokens
s.trackAiMessage(...) auto-calculates [Agent] Cost USD from the model name and token counts through the bundled Pydantic genai-prices catalog.
Three things prevent automatic pricing:
- Unrecognized model name. Vertex AI aliases like
claude-sonnet-4-6won't match the canonicalclaude-sonnet-4-20250514. Internal gateway labels won't resolve. Brand-new models may not yet be in genai-prices. Pass the canonical provider id, or settotalCostUsdexplicitly to override. - Fine-tuned models.
ft:model names never auto-price; passtotalCostUsdexplicitly for fine-tuned and custom models. - Incorrect
inputTokenswith prompt caching. The SDK expectsinputTokensto be cache-inclusive (cached tokens are a subset, never additive). Provider conventions differ:
Provider-name quirks to know:
- Gemini → google (Node). The Node SDK maps
geminitogoogleinternally for price lookup. PassingdefaultProvider: 'gemini'still resolves cost, but if you inspect the raw catalog and expect to seegemini, look forgoogleinstead. - Bedrock candidate generation. The lookup strips dot-separated prefixes progressively (
region.vendor.model→vendor.model→model) and triesregional.andglobal.variants, which is why new AWS regions and Bedrock vendors work automatically without a catalog update. - Local Python rate overrides. The Python SDK carries local rate tables in
costs.pythat fill gaps in the upstream catalog:gpt-5.6(upstream misses the cache-write premium and long-context tier), Fireworksfastrouters (billed at the fast tier even when the API response reports the base model ID), and a_MODEL_PRICE_ALIASESmap that points, for example,gpt-5.4atgpt-5.2pricing when upstream lags an OpenAI release.
| Provider | Raw API behavior | What to pass as inputTokens |
|---|---|---|
| OpenAI | prompt_tokens already includes cached_tokens | Use directly |
| Anthropic / Bedrock (Converse) | input_tokens excludes cache tokens | input_tokens + cache_read_input_tokens + cache_creation_input_tokens |
| Gemini | promptTokenCount includes cached; cachedContentTokenCount reports separately | Use promptTokenCount directly |
The built-in Anthropic, Bedrock, and Gemini wrappers handle this normalization for you. Manual trackAiMessage callers need to handle it themselves. Pass cacheReadTokens / cacheCreationTokens separately so the SDK applies the differential pricing.
When you need to compute cost yourself, call calculateCost({ modelName, inputTokens, outputTokens, cacheReadInputTokens, cacheCreationInputTokens }) and pass the result as totalCostUsd.
Rules for calculateCost():
inputTokensis the total input, including cache reads and cache creations. For Anthropic, passinput_tokens + cache_read_input_tokens + cache_creation_input_tokens. For OpenAI,prompt_tokensalready includes cached tokens, so pass it directly.outputTokensis the total output, including reasoning tokens where the provider emits them. OpenAI'scompletion_tokensalready includes reasoning; don't add it separately.cacheReadInputTokensandcacheCreationInputTokensare subsets ofinputTokens, used only to apply the differential pricing rate.- The
reasoningTokensparameter is deprecated and ignored. It's kept for backward compatibility; passing it separately over-costs the request.
Debugging missing costs
When the SDK can't calculate a cost, it logs one warning per unique (model, provider, reason) tuple, capped at 100 unique tuples per process. Grep your logs for Unable to calculate cost for model= to see which lookups failed and why.
Report run cost for non-conversational agents
Provider wrappers emit [Agent] Cost USD automatically on every [Agent] AI Response. Agents that finish a run without a final text response, such as batch jobs and artifact generators, may never emit an [Agent] AI Response, so their cost never lands. Call trackRunCost() at the end of the run to emit the cost the per-call events didn't cover:
s.trackRunCost(totalCostUsd, inputTokens, outputTokens, model, "openai", {
latencyMs,
content: "[Artifact: batch run]", // optional; omit for a cost-only event
});
s.track_run_cost(
total_cost_usd,
input_tokens,
output_tokens,
model,
"openai",
latency_ms=latency_ms,
content="[Artifact: batch run]", # optional; omit for a cost-only event
)
trackRunCost() emits delta cost only, so it reconciles with any per-call costs already tracked in the run. It defaults to empty content, so omit content for a cost-only balancing event, or pass a short string when you want a bubble in the session viewer. Attach cost to run completion this way rather than to [Agent] Session End, which is lifecycle-only and doesn't carry cost fields.
Keep pricing data current
Cost relies on the bundled genai-prices catalog, so a newly released model can report [Agent] Cost USD of 0 until the catalog updates. To fetch the latest prices at runtime, opt in at startup with enableLivePriceUpdates() (Node) or enable_live_price_updates() (Python).
- Default state: off. You must opt in.
- Default refresh interval: 1 hour (
3_600_000ms on Node,3600s on Python). Configurable via the first argument. - Upstream endpoint: public
raw.githubusercontent.com, the Pydanticgenai-pricesGitHub repo. Not an Amplitude-owned endpoint. - Failure mode: silent. Network errors are swallowed; the bundled catalog stays in use.
- Idempotent: a second call is a no-op.
- How to know it's working: no debug flag or status output. The only signal is
[Agent] Cost USDstarting to populate for a model that was previously missing cost.
Enable it when: you've upgraded to a newly released model that isn't in the bundled catalog yet. Without the toggle, [Agent] Cost USD stays omitted for that model until the SDK version bumps.
Don't enable it when: your process runs air-gapped, or your environment blocks outbound HTTPS to raw.githubusercontent.com. There's no benefit and every startup pays a failed network round-trip.
Capture deploy metadata
The SDK reads deploy-identifying environment variables at startup and stamps them onto every [Agent] event. This lets you filter charts by SHA or release without threading the value through your code.
| Env var | Fallback | Emits as | Behavior |
|---|---|---|---|
AMPLITUDE_GIT_SHA | GIT_SHA | [Agent] Git SHA | Read verbatim. |
AMPLITUDE_GIT_REF | GIT_REF | [Agent] Git Ref | Read verbatim. Typically a branch name or tag. |
AMPLITUDE_GIT_REPO | GIT_REPO | [Agent] Git Repo | Opt-in only. Sanitized: userinfo (user:pass@) is stripped, and the SDK logs one warning if a credential was stripped. |
The repo URL is opt-in via env var only. Earlier SDK releases auto-captured the repo from git metadata; that was removed. If [Agent] Git Repo went empty after an SDK upgrade, set AMPLITUDE_GIT_REPO explicitly.
Track semantic cache hits
When you serve a full response from your own semantic or response cache, pass wasCached: true (Node) or was_cached=True (Python) on the AI-message call. It maps to [Agent] Was Cached, distinct from token-level prompt caching, so you can chart cache-hit rate and the cost it saves.
Shape message content
The first argument to trackUserMessage becomes $llm_message.text on [Agent] User Message. This is what session lists, segmentation, and enrichment treat as "what the user said". Two practical rules:
Do pass a short natural-language line as the message body. For example, the real prompt, or a canonical summary for headless jobs:
s.trackUserMessage(
"Summarize the attached design doc and list open questions",
{
context: { structuredPayload: payloadRecord },
},
);
Don't pass large JSON blobs as the message body. The product uses the JSON as the session title and breaks down charts by raw JSON:
// Session label becomes the JSON
s.trackUserMessage(JSON.stringify(payloadRecord));
Put structured segmentation dimensions in the context option (becomes [Agent] Context JSON, queryable in charts). For server-side enrichment to reason over structured data, also keep essential facts in content. Enrichments derive eval input primarily from turn text, not from [Agent] Context.
Instrument without the SDK
For unsupported runtimes, such as Java, Go, Ruby, browsers, and edge environments, send [Agent] events to the Amplitude HTTP API directly. Refer to Send agent events without the AI SDK for the steps and the Event contract for required properties.
Verify your data
To check your instrumentation, including the amplitude-ai doctor command, the Live Events gates, and the summary() fill-rate report, refer to Verify your Agent Analytics instrumentation.
Test against a mock client
For CI, use MockAmplitudeAI from @amplitude/ai/testing to assert your events emit correctly:
import { AIConfig } from "@amplitude/ai";
import { MockAmplitudeAI } from "@amplitude/ai/testing";
const mock = new MockAmplitudeAI(new AIConfig({ contentMode: "full" }));
const agent = mock.agent("test-agent", { userId: "u1" });
await agent.session({ sessionId: "s1" }).run(async (s) => {
s.trackUserMessage("hello");
s.trackAiMessage("response", "gpt-4o-mini", "openai", 150);
});
mock.assertEventTracked("[Agent] User Message", { userId: "u1" });
mock.assertSessionClosed("s1");
// Data quality gate: every AI Response must carry the eight verification fields
for (const e of mock.eventsOfType("[Agent] AI Response")) {
const p = e.event_properties ?? {};
expect(e.user_id || e.device_id).toBeTruthy();
expect(p["[Agent] Session ID"]).toBeTruthy();
expect(p["[Agent] Model Name"]).toBeTruthy();
expect(p["[Agent] Provider"]).toBeTruthy();
expect(p["[Agent] Latency Ms"]).toBeGreaterThan(0);
expect(p["[Agent] Input Tokens"]).toBeGreaterThan(0);
expect(p["[Agent] Output Tokens"]).toBeGreaterThan(0);
expect(p["[Agent] Cost USD"]).toBeGreaterThan(0);
}
Keep this test in CI to catch silent instrumentation regressions such as bad model names or missing token counts produce broken dashboards without throwing at runtime.
Reliability and error handling
Instrumentation can't take your application down:
- Tracking calls never throw. Every
track*method catches and logs its own errors internally. A serialization bug or a bad field can't interrupt your agent's request path. - The SDK buffers and retries events. The underlying
@amplitude/analytics-nodeclient batches events and retries failed sends from its transport layer. - Failures degrade gracefully. If Amplitude is unreachable, the SDK drops events silently after exhausting retries. Your application keeps operating.
For development, set validate: true (Node) or validate=True (Python) on AIConfig to surface missing required fields, such as userId or sessionId, early. Validation errors throw ValidationError so you can catch them in tests before they reach production. Combine with dryRun / dry_run for the strictest CI checking.
Auto-instrument and CLI tools
To instrument without editing any call sites, auto-patch supported providers at process start. This is the fastest way to confirm the SDK is wired up; for the full event model (user messages, sessions, scores), use agents and sessions as shown in Initialize the SDK.
# Wrapper command
AMPLITUDE_AI_API_KEY=xxx AMPLITUDE_AI_AUTO_PATCH=true amplitude-ai-instrument node app.js
# Or Node's ESM preload flag directly
AMPLITUDE_AI_API_KEY=xxx AMPLITUDE_AI_AUTO_PATCH=true node --import @amplitude/ai/register app.js
Both runtimes read the same environment variables:
| Variable | Description |
|---|---|
AMPLITUDE_AI_API_KEY | Required to enable auto-patch. |
AMPLITUDE_AI_AUTO_PATCH | Must be "true" to turn auto-patching on. |
AMPLITUDE_AI_CONTENT_MODE | full (default), metadata_only, or customer_enriched. |
AMPLITUDE_AI_DEBUG | "true" to log each event to stderr. |
AMPLITUDE_AI_REVIEW | "true" to capture sanitized upload previews without sending them during auto-instrumentation. Setting AMPLITUDE_AI_DEBUG doesn't enable this. |
Other CLI commands:
| Command | Runtime | What it does |
|---|---|---|
amplitude-ai | Node, Python | Prints the prompt to paste into your AI coding agent. |
amplitude-ai doctor | Node, Python | Checks dependencies, environment, and the event pipeline. In Python, also amplitude-ai-doctor. |
amplitude-ai status | Node, Python | Prints the SDK version, detected provider packages, and environment configuration. |
amplitude-ai mcp | Node, Python | Starts a local stdio MCP server that gives your AI coding agent tools to scan, instrument, and verify your app. It works on your source code and doesn't read your Amplitude data. In Python, install amplitude-ai[mcp] first. |
amplitude-ai verify | Python | Runs local checks: SDK installed, API key set, provider detected, and a verify test present. Add --live for steps to confirm sessions in Amplitude. |
amplitude-ai-completions bash or zsh | Node | Prints a shell completion script for the amplitude-ai commands. |
To inspect the environment without running your app, use amplitude-ai status. It prints the installed SDK version, the provider packages it detects, and the current environment-variable configuration. To validate dependencies and the event-pipeline connection, refer to Verify your data for the doctor command.
Register the event schema in your data catalog
The SDK ships a CLI that registers all [Agent] event types and their properties in Amplitude's Data Catalog, so events arrive documented with descriptions, types, and required flags instead of being inferred from ingestion.
Prerequisites: a plan with Taxonomy API access, and the project's API key and secret key from Settings > Projects.
The bundled CLI reads the event catalog and prints a bash script of curl commands. It makes no network requests itself. Write the script to a file, review it, then run it. The script reads AMPLITUDE_API_KEY and AMPLITUDE_SECRET_KEY from the environment when it runs, so export them in the shell that runs it.
# Write the script (add --eu for EU data residency)
npx -y -p @amplitude/ai amplitude-ai-register-catalog > register.sh
# Review register.sh, then run it with AMPLITUDE_API_KEY and AMPLITUDE_SECRET_KEY exported
bash register.sh
Neither CLI accepts a secret key as a command-line value, because other local users can read process arguments and shells keep them in history. The Node CLI ignores --api-key and --secret-key and prints a warning. The Python CLI rejects a literal --secret-key value.
The commands are idempotent: they create missing events and properties and update existing ones, so it's safe to re-run after an SDK upgrade adds new fields.
Debug and dry-run
Debug and dry-run are two AIConfig flags for inspecting events locally. Each has an environment-variable equivalent for auto-instrumentation. For review mode, refer to Review outbound traffic.
debug: true (Node) / debug=True (Python) logs a one-line summary of every event to stderr and still sends events to Amplitude:
[amplitude-ai] [Agent] AI Response | user=user-123 session=sess-abc agent=my-agent model=gpt-4o latency=1203ms tokens=150→847 cost=$0.0042
dryRun: true (Node) / dry_run=True (Python) logs the full event JSON to stderr and never transmits anything. Use it to validate event shape in local development and CI without a live API key. With auto-instrumentation, set AMPLITUDE_AI_DEBUG=true on the command instead.
Review outbound traffic
Review mode records the event handed to the analytics client after privacy redaction and prints a sanitized upload preview. It sends nothing. Use it to inspect the request instrumentation would make during a security review.
Review mode labels previews pre-transport. They show the event after redaction, before gzip, retries, or fields the analytics SDK adds later, such as insert_id and library metadata. The envelope API key is [REDACTED]. Previews keep prompt and message content intact, so don't commit the artifact.
const ai = new AmplitudeAI({
apiKey: process.env.AMPLITUDE_AI_API_KEY!,
config: new AIConfig({ reviewMode: true, validate: true }),
});
// Exercise one representative session, then:
await ai.flush();
console.log(ai.getReviewTraffic());
patch({ amplitudeAI: ai }), wrap(), and agent().session() all use this client, so reviewMode: true covers those paths. For zero-code instrumentation, set AMPLITUDE_AI_REVIEW=true.
The event callback fires once per captured event with status -1 and message review-mode. flush() still flushes the underlying Amplitude client, so it doesn't strand unrelated product events on a shared client. Confirm in the network panel that no Amplitude upload left the process. AMPLITUDE_AI_DEBUG doesn't enable review mode.
Troubleshooting
For symptoms such as missing Session Records, events that don't group into sessions, empty message content, and missing costs, refer to Troubleshoot Agent Analytics setup.
API reference
Core classes
| API | Purpose |
|---|---|
new AmplitudeAI({ apiKey, config? }) | Initialize the SDK |
new AIConfig({ contentMode?, redactPii?, customRedactionPatterns?, customRedactionFn?, dryRun?, reviewMode?, debug? }) | Privacy, debug, and review config |
ai.agent(agentId, opts?) | Create a bound agent |
agent.child(agentId, opts?) | Create a child agent for delegation |
agent.session(opts?) | Create a session (auto-flushes in serverless) |
session.run(fn) | Execute work with session context |
s.runAs(childAgent, fn) | Delegate to a child agent |
ai.enableOtel() / ai.enable_otel() | Enable OTEL span-first instrumentation |
ai.otelEnabled / ai.otel_enabled | Whether OTEL mode is active (read-only) |
ai.flush() | Flush buffered events (serverless / streaming) |
ai.getReviewTraffic() / ai.get_review_traffic() | Closed upload previews plus the still-open batch, when review mode is on |
get_patch_review_traffic() | Previews captured by Python patch(review_mode=True) or AMPLITUDE_AI_REVIEW |
ai.shutdown() | Flush, then close the analytics client (process exit) |
ai.tenant(orgId, opts?) | Tenant-scoped handle that pre-binds customerOrgId |
ai.score({ userId, name, value, targetId?, targetType?, source? }) | Record explicit user feedback as [Agent] Score |
Session tracking methods
| Method | Event |
|---|---|
s.trackUserMessage(content, opts?) | [Agent] User Message |
s.trackAiMessage(content, model, provider, latencyMs, opts?) | [Agent] AI Response |
s.trackToolCall(name, latencyMs, success, opts?) | [Agent] Tool Call |
s.trackSpan({ name, latencyMs, ... }) | [Agent] Span |
s.trackEmbedding(model, provider, latencyMs, opts?) | [Agent] Embedding |
s.trackSessionEnrichment({...}) | Session-level enrichment (customer_enriched mode) |
Higher-order functions
| HOF | Event | Use |
|---|---|---|
tool(fn, { name }) | [Agent] Tool Call | Wrap tool functions |
observe(fn, { name, type? }) | [Agent] Span | Wrap any function for observability (with OTEL: creates real spans; type controls event routing) |
Other APIs
| API | Use |
|---|---|
patch({ amplitudeAI: ai }) / unpatch() | Zero-code instrumentation, auto-extracts Tool Calls from message arrays |
wrap(client, ai) | Wrap an existing provider client without modifying its construction |
injectContext() / extractContext(headers) | Cross-service propagation |
usingAttributes(attrs, fn) / using_attributes(**attrs) | Attach identity and session context to OTEL spans |
updateCurrentSpan(attrs) / update_current_span(**attrs) | Update attributes on the active OTEL span |
createAmplitudeAIMiddleware(opts) / AmplitudeAIMiddleware | Express, Fastify, and Hono middleware (Node); FastAPI and Starlette middleware (Python) |
StreamingAccumulator | Collect a stream you track manually into one AI response |
calculateCost({ modelName, ... }) | Compute cost directly when you need to override totalCostUsd |
trackRunCost(...) / track_run_cost(...) | Emit run-end delta [Agent] Cost USD for non-conversational agents |
trackConversation({ ... }) | Backfill a full message history as events |
inferModelTier(model) | Resolve a model's tier (fast / standard / reasoning) |
enableLivePriceUpdates() | Refresh genai-prices cost data at runtime |
MockAmplitudeAI (@amplitude/ai/testing) | Deterministic test double; call .summary() for a fill-rate report |
ClaudeAgentSDKTracker (@amplitude/ai/integrations/claude-agent-sdk) | Claude Agent SDK integration |
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