graph TB
    subgraph "Streaming Challenges"
        PartialJSON[Partial JSON Stream]
        PartialXML[Partial XML Stream]
        Progress[Concurrent Progress]

        PartialJSON --> Parser1[Streaming JSON Parser]
        PartialXML --> Parser2[Custom XML Parser]
        Progress --> Aggregator[Progress Aggregator]
    end

    subgraph "Data Challenges"
        LargeObjects[Large Objects]
        Circular[Circular Refs]
        TypedData[Special Types]

        LargeObjects --> Normalizer[normalizeToSize]
        Circular --> Normalizer
        TypedData --> Normalizer
    end

    subgraph "LLM Challenges"
        Errors[Tool Errors]
        Context[Dynamic Context]
        Synthesis[Multi-Result]

        Errors --> Formatter[Error Formatter]
        Context --> Assembler[Context Assembly]
        Synthesis --> Synthesizer[AgentTool Synthesis]
    end

The Streaming JSON Parser: Handling LLM's Partial Thoughts

When an LLM streams a tool use request, it doesn't send complete JSON all at once. Instead, you might receive fragments like:

{"file_path": "/src/
{"file_path": "/src/main.
{"file_path": "/src/main.ts", "old_str
{"file_path": "/src/main.ts", "old_string": "console.log('hell

The streaming JSON parser solves this elegantly:

class StreamingToolInputParser {
  private buffer: string = '';
  private state = {
    depth: 0,           // Nesting level of {}/[]
    inString: boolean,  // Currently inside a string?
    escape: boolean,    // Previous char was backslash?
    stringChar: '"' | "'" | null,  // Which quote started current string
  };

  addChunk(chunk: string): ParseResult {
    this.buffer += chunk;

    // Update parser state character by character
    for (let i = 0; i < chunk.length; i++) {
      const char = chunk[i];
      const prevChar = i > 0 ? chunk[i-1] : this.buffer[this.buffer.length - chunk.length - 1];

      // Handle escape sequences
      if (this.escape) {
        this.escape = false;
        continue;
      }

      if (char === '\\\\\\\\' && this.state.inString) {
        this.escape = true;
        continue;
      }

      // String boundary detection
      if (!this.state.inString && (char === '"' || char === "'")) {
        this.state.inString = true;
        this.state.stringChar = char;
      } else if (this.state.inString && char === this.state.stringChar) {
        this.state.inString = false;
        this.state.stringChar = null;
      }

      // Track nesting depth outside strings
      if (!this.state.inString) {
        if (char === '{' || char === '[') {
          this.state.depth++;
        } else if (char === '}' || char === ']') {
          this.state.depth--;

          // Attempt parse when we return to depth 0
          if (this.state.depth === 0) {
            return this.tryParse();
          }
        }
      }
    }

    // Might be complete even without depth 0 (malformed JSON)
    if (this.buffer.length > 10000) { // Safety limit
      return this.tryParseWithRecovery();
    }

    return { complete: false };
  }

  private tryParse(): ParseResult {
    try {
      const parsed = JSON.parse(this.buffer);
      return { complete: true, value: parsed };
    } catch (e) {
      return { complete: false, partial: this.buffer };
    }
  }

  private tryParseWithRecovery(): ParseResult {
    let attemptBuffer = this.buffer;

    // Recovery strategy 1: Close unclosed strings
    if (this.state.inString && this.state.stringChar) {
      attemptBuffer += this.state.stringChar;

      // Try to close any unclosed structures
      attemptBuffer += '}'.repeat(Math.max(0, this.state.depth));
      attemptBuffer += ']'.repeat(
        Math.max(0, (attemptBuffer.match(/\\\\[/g) || []).length -
                    (attemptBuffer.match(/\\\\]/g) || []).length)
      );
    }

    // Recovery strategy 2: Auto-close based on structure analysis
    const braceBalance = (attemptBuffer.match(/{/g) || []).length -
                        (attemptBuffer.match(/}/g) || []).length;
    const bracketBalance = (attemptBuffer.match(/\\\\[/g) || []).length -
                          (attemptBuffer.match(/\\\\]/g) || []).length;

    attemptBuffer += '}'.repeat(Math.max(0, braceBalance));
    attemptBuffer += ']'.repeat(Math.max(0, bracketBalance));

    try {
      const parsed = JSON.parse(attemptBuffer);
      return {
        complete: true,
        value: parsed,
        wasRepaired: true,
        repairs: {
          closedStrings: this.state.inString,
          addedBraces: braceBalance,
          addedBrackets: bracketBalance
        }
      };
    } catch (e) {
      // Recovery strategy 3: Extract what we can
      const partialResult = this.extractPartialData(this.buffer);
      return {
        complete: false,
        partial: partialResult,
        error: e.message
      };
    }
  }

  private extractPartialData(buffer: string): any {
    // Try to extract complete key-value pairs
    const result: any = {};
    const keyValuePattern = /"(\\\\w+)":\\\\s*("([^"\\\\\\\\]*(\\\\\\\\.[^"\\\\\\\\]*)*)"|true|false|null|\\\\d+)/g;

    let match;
    while ((match = keyValuePattern.exec(buffer)) !== null) {
      const [, key, value] = match;
      try {
        result[key] = JSON.parse(value);
      } catch {
        result[key] = value; // Store as string if parse fails
      }
    }

    return Object.keys(result).length > 0 ? result : null;
  }
}

Why This Is Novel:

• Traditional JSON parsers fail on incomplete input
• This parser provides progressive parsing with meaningful partial results
• Recovery strategies handle common LLM streaming issues
• Enables responsive UI that shows tool inputs as they stream

Performance Characteristics:

The normalizeToSize Algorithm: Smart Data Truncation

When sending data to LLMs or telemetry services, size limits are critical. The normalizeToSize algorithm intelligently reduces object size while preserving structure:

class DataNormalizer {
  static normalizeToSize(
    obj: any,
    maxDepth: number = 3,
    maxSizeInBytes: number = 100_000
  ): any {
    // First attempt at full depth
    let normalized = this.normalize(obj, maxDepth);
    let size = this.estimateSize(normalized);

    // Iteratively reduce depth until size fits
    while (size > maxSizeInBytes && maxDepth > 0) {
      maxDepth--;
      normalized = this.normalize(obj, maxDepth);
      size = this.estimateSize(normalized);
    }

    return normalized;
  }

  private static normalize(
    obj: any,
    maxDepth: number,
    currentDepth: number = 0,
    visited = new WeakSet()
  ): any {
    // Handle primitives
    if (obj === null) return '[null]';
    if (obj === undefined) return '[undefined]';
    if (typeof obj === 'number' && isNaN(obj)) return '[NaN]';
    if (typeof obj === 'bigint') return `[BigInt: ${obj}n]`;

    // Handle functions and symbols
    if (typeof obj === 'function') {
      return `[Function: ${obj.name || 'anonymous'}]`;
    }
    if (typeof obj === 'symbol') {
      return `[Symbol: ${obj.description || 'Symbol'}]`;
    }

    // Primitives pass through
    if (['string', 'number', 'boolean'].includes(typeof obj)) {
      return obj;
    }

    // Depth limit reached
    if (currentDepth >= maxDepth) {
      if (Array.isArray(obj)) return `[Array(${obj.length})]`;
      if (obj.constructor?.name) {
        return `[${obj.constructor.name}]`;
      }
      return '[Object]';
    }

    // Circular reference detection
    if (visited.has(obj)) {
      return '[Circular]';
    }
    visited.add(obj);

    // Special handling for known types
    if (this.isReactElement(obj)) {
      return `[React.${obj.type?.name || obj.type || 'Element'}]`;
    }

    if (this.isVueComponent(obj)) {
      return `[Vue.${obj.$options?.name || 'Component'}]`;
    }

    if (obj instanceof Error) {
      return {
        name: obj.name,
        message: obj.message,
        stack: this.truncateStack(obj.stack)
      };
    }

    if (obj instanceof Date) {
      return obj.toISOString();
    }

    if (obj instanceof RegExp) {
      return obj.toString();
    }

    // Handle DOM elements
    if (this.isDOMElement(obj)) {
      return `[${obj.tagName}${obj.id ? '#' + obj.id : ''}]`;
    }

    // Handle toJSON method
    if (typeof obj.toJSON === 'function') {
      try {
        return this.normalize(
          obj.toJSON(),
          maxDepth,
          currentDepth,
          visited
        );
      } catch {
        return '[Object with toJSON error]';
      }
    }

    // Arrays
    if (Array.isArray(obj)) {
      const result = [];
      const maxItems = 100; // Limit array size

      for (let i = 0; i < Math.min(obj.length, maxItems); i++) {
        result.push(
          this.normalize(obj[i], maxDepth, currentDepth + 1, visited)
        );
      }

      if (obj.length > maxItems) {
        result.push(`... ${obj.length - maxItems} more items`);
      }

      return result;
    }

    // Objects
    const result: any = {};
    const keys = Object.keys(obj);
    const maxProps = 50; // Limit object properties

    // Respect Sentry directives
    if (obj.__sentry_skip_normalization__) {
      return obj;
    }

    const effectiveMaxDepth =
      obj.__sentry_override_normalization_depth__ || maxDepth;

    for (let i = 0; i < Math.min(keys.length, maxProps); i++) {
      const key = keys[i];
      try {
        result[key] = this.normalize(
          obj[key],
          effectiveMaxDepth,
          currentDepth + 1,
          visited
        );
      } catch {
        result[key] = '[Error accessing property]';
      }
    }

    if (keys.length > maxProps) {
      result['...'] = `${keys.length - maxProps} more properties`;
    }

    return result;
  }

  private static estimateSize(obj: any): number {
    // Fast estimation without full serialization
    const sample = JSON.stringify(obj).substring(0, 1000);
    const avgCharSize = new Blob([sample]).size / sample.length;

    const fullLength = this.estimateJsonLength(obj);
    return Math.ceil(fullLength * avgCharSize);
  }

  private static estimateJsonLength(obj: any, visited = new WeakSet()): number {
    if (obj === null || obj === undefined) return 4; // "null"
    if (typeof obj === 'boolean') return obj ? 4 : 5; // "true" : "false"
    if (typeof obj === 'number') return String(obj).length;
    if (typeof obj === 'string') return obj.length + 2; // quotes

    if (visited.has(obj)) return 12; // "[Circular]"
    visited.add(obj);

    if (Array.isArray(obj)) {
      let length = 2; // []
      for (const item of obj) {
        length += this.estimateJsonLength(item, visited) + 1; // comma
      }
      return length;
    }

    if (typeof obj === 'object') {
      let length = 2; // {}
      for (const key in obj) {
        length += key.length + 3; // "key":
        length += this.estimateJsonLength(obj[key], visited) + 1; // comma
      }
      return length;
    }

    return 10; // Default estimate
  }
}

Why This Is Novel:

• Iterative depth reduction based on actual byte size
• Type-aware stringification for special objects
• Respects framework-specific objects (React, Vue)