---
title: "resolveLibraryId"
sidebarTitle: "resolveLibraryId"
description: "Search for libraries and resolve them to Context7-compatible IDs"
---
The `resolveLibraryId` tool searches Context7's library database and returns matching results with their Context7-compatible library IDs. This is typically the first step in a documentation lookup workflow.
## Usage
```typescript
import { resolveLibraryId } from "@upstash/context7-tools-ai-sdk";
import { generateText, stepCountIs } from "ai";
import { openai } from "@ai-sdk/openai";
const { text } = await generateText({
model: openai("gpt-5.2"),
prompt: "Find documentation for React hooks",
tools: {
resolveLibraryId: resolveLibraryId(),
},
stopWhen: stepCountIs(3),
});
```
## Configuration
```typescript
resolveLibraryId(config?: Context7ToolsConfig)
```
### Parameters
<ParamField path="config" type="Context7ToolsConfig" optional>
Configuration options for the tool.
<Expandable title="properties">
<ParamField path="apiKey" type="string" optional>
Context7 API key. If not provided, uses the `CONTEXT7_API_KEY` environment variable.
</ParamField>
</Expandable>
</ParamField>
### Returns
Returns an AI SDK `tool` that can be used with `generateText`, `streamText`, or agents.
## Tool Behavior
When the AI model calls this tool, it:
1. Takes a `query` and `libraryName` parameter from the model
2. Searches Context7's database for matching libraries
3. Returns formatted results including:
- Library ID (e.g., `/reactjs/react.dev`)
- Title and description
- Number of code snippets available
- Source reputation score
- Available versions
### Input Schema
The tool accepts the following input from the AI model:
<ParamField path="query" type="string" required>
The user's original question or task. This is used to rank library results by relevance to what the user is trying to accomplish.
</ParamField>
<ParamField path="libraryName" type="string" required>
Library name to search for (e.g., "react", "next.js", "vue")
</ParamField>
### Output Format
On success, the tool returns the search results as plain text, formatted for easy consumption by the AI model:
```
- Title: React Documentation
- Context7-compatible library ID: /reactjs/react.dev
- Description: The library for web and native user interfaces
- Code Snippets: 1250
- Trust Score: High
- Benchmark Score: 98
- Versions: 19.0.0, 18.3.1, 18.2.0
----------
- Title: React Native
- Context7-compatible library ID: /facebook/react-native
- Description: A framework for building native applications using React
- Code Snippets: 890
- Trust Score: High
- Benchmark Score: 95
- Versions: 0.76.0, 0.75.4
```
On failure:
```
No libraries found matching "unknown-lib". Try a different search term or check the library name.
```
## Examples
### Basic Usage
```typescript
import { resolveLibraryId, queryDocs } from "@upstash/context7-tools-ai-sdk";
import { generateText, stepCountIs } from "ai";
import { openai } from "@ai-sdk/openai";
const { text, toolCalls } = await generateText({
model: openai("gpt-5.2"),
prompt: "What libraries are available for React?",
tools: {
resolveLibraryId: resolveLibraryId(),
queryDocs: queryDocs(),
},
stopWhen: stepCountIs(5),
});
// The model will call resolveLibraryId and receive a list of matching libraries
console.log(text);
```
### With Custom API Key
```typescript
import { resolveLibraryId } from "@upstash/context7-tools-ai-sdk";
const tool = resolveLibraryId({
apiKey: process.env.CONTEXT7_API_KEY,
});
```
### Inspecting Tool Calls
```typescript
import { resolveLibraryId } from "@upstash/context7-tools-ai-sdk";
import { generateText, stepCountIs } from "ai";
import { openai } from "@ai-sdk/openai";
const { toolCalls, toolResults } = await generateText({
model: openai("gpt-5.2"),
prompt: "Find the official Next.js documentation",
tools: {
resolveLibraryId: resolveLibraryId(),
},
stopWhen: stepCountIs(3),
});
// See what the model searched for
for (const call of toolCalls) {
console.log("Searched for:", call.args.libraryName);
}
// See the results
for (const result of toolResults) {
console.log("Found:", result.result);
}
```
## Selection Guidance
The tool's description instructs the AI model to select libraries based on:
1. **Name similarity** - Exact matches are prioritized
2. **Description relevance** - How well the description matches the query intent
3. **Documentation coverage** - Libraries with more code snippets are preferred
4. **Source reputation** - High/Medium reputation sources are more authoritative
5. **Benchmark score** - Quality indicator (100 is the highest)
## Related
- [queryDocs](/agentic-tools/ai-sdk/tools/query-docs) - Fetch documentation using the resolved library ID
- [Context7Agent](/agentic-tools/ai-sdk/agents/context7-agent) - Pre-built agent that handles the full workflow
