@chat-adapter/shared

Shared utilities for Chat SDK adapters. Provides common helpers used across adapter implementations.

Installation

pnpm add @chat-adapter/shared

Utilities

Adapter helpers

• extractCard(message) - extract a CardElement from an AdapterPostableMessage
• extractFiles(message) - extract FileUpload[] from an AdapterPostableMessage

Buffer conversion

• toBuffer(input) - convert various inputs (Buffer, Blob, string, URL) to Buffer
• toBufferSync(input) - synchronous version of toBuffer
• bufferToDataUri(buffer, mimeType) - convert a Buffer to a data URI string

Card conversion

• cardToFallbackText(card) - render a CardElement as plain text for platforms that don't support cards
• createEmojiConverter(platform) - create a function that converts emoji placeholders to platform format
• mapButtonStyle(style) - map generic button styles to platform-specific variants
• renderGfmTable(headers, rows) - render a GitHub Flavored Markdown table
• escapeTableCell(text) - escape pipe characters in table cells

Token encryption

AES-256-GCM helpers for encrypting OAuth tokens at rest before writing them to a state adapter. Used by @chat-adapter/slack and @chat-adapter/linear; available to any adapter that persists credentials.

• encryptToken(plaintext, key) - encrypt a string and return an EncryptedTokenData envelope (random 12-byte IV per call)
• decryptToken(data, key) - decrypt an envelope back to the original string
• decodeKey(encoded) - decode a hex-64 or base64-44 encoded 32-byte key; throws on wrong length
• isEncryptedTokenData(value) - type guard for distinguishing envelopes from legacy plaintext records
• EncryptedTokenData - the envelope type ({ data, iv, tag }, all base64)

Error classes

Standardized errors for adapter implementations:

• AdapterError - base error class
• AdapterRateLimitError - platform rate limit (includes retryAfter)
• AuthenticationError - expired or invalid tokens
• NetworkError - connection failures
• PermissionError - missing scopes or permissions
• ResourceNotFoundError - missing channel/thread/message
• ValidationError - invalid config or input

License

MIT