Function getExtraBodyParams

src/services/api/claude.ts:272–331

(betaHeaders?: string[])

 * @returns A JSON object representing the extra body parameters.
 */
export function getExtraBodyParams(betaHeaders?: string[]): JsonObject {
  // Parse user's extra body parameters first
  const extraBodyStr = process.env.CLAUDE_CODE_EXTRA_BODY
  let result: JsonObject = {}

  if (extraBodyStr) {
    try {
      // Parse as JSON, which can be null, boolean, number, string, array or object
      const parsed = safeParseJSON(extraBodyStr)
      // We expect an object with key-value pairs to spread into API parameters
      if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
        // Shallow clone — safeParseJSON is LRU-cached and returns the same
        // object reference for the same string. Mutating `result` below
        // would poison the cache, causing stale values to persist.
        result = { ...(parsed as JsonObject) }
      } else {
        logForDebugging(
          `CLAUDE_CODE_EXTRA_BODY env var must be a JSON object, but was given ${extraBodyStr}`,
          { level: 'error' },
        )
      }
    } catch (error) {
      logForDebugging(
        `Error parsing CLAUDE_CODE_EXTRA_BODY: ${errorMessage(error)}`,
        { level: 'error' },
      )
    }
  }

  // Anti-distillation: send fake_tools opt-in for 1P CLI only
  if (
    feature('ANTI_DISTILLATION_CC')
      ? process.env.CLAUDE_CODE_ENTRYPOINT === 'cli' &&
        shouldIncludeFirstPartyOnlyBetas() &&
        getFeatureValue_CACHED_MAY_BE_STALE(
          'tengu_anti_distill_fake_tool_injection',
          false,
        )
      : false
  ) {
    result.anti_distillation = ['fake_tools']
  }

  // Handle beta headers if provided
  if (betaHeaders && betaHeaders.length > 0) {
    if (result.anthropic_beta && Array.isArray(result.anthropic_beta)) {
      // Add to existing array, avoiding duplicates
      const existingHeaders = result.anthropic_beta as string[]
      const newHeaders = betaHeaders.filter(
        header => !existingHeaders.includes(header),
      )
      result.anthropic_beta = [...existingHeaders, ...newHeaders]
    } else {
      // Create new array with the beta headers
      result.anthropic_beta = betaHeaders
    }
  }