chat-go

chat-go is a Go port of Vercel's Chat SDK v4.40.0. It holds the shared message types, three platform adapters, and two state stores. Your program owns the turn.

The module path is github.com/northpolesec/chat-go.

How a message moves

A platform sends a webhook. The adapter checks the signature. Then it parses the event. Then it calls your chat.ChatInstance.

Your code reads and writes state. Then it posts or streams a reply through the same adapter.

platform webhook
       |
       v
    adapter -------- state (memory or Postgres)
       |
       v
 your ChatInstance
       |
       v
 adapter post or stream
       |
       v
  platform API

The adapter stores each platform thread as one string. EncodeThreadID and DecodeThreadID convert that string.

chat.ChatInstance is the surface your program implements. On Slack, ProcessMessage and the other Process* methods must return before the ack. The adapter waits for them, then acks the webhook. Slack sends the event again after about 3 seconds.

Packages

chat/            messages, cards, markdown, adapter and state interfaces
slack/           Slack adapter (slack/api, slack/blocks, slack/webhook)
github/          GitHub adapter
linear/          Linear adapter
statememory/     in-memory state
statepg/         Postgres state
chattest/        contract tests for adapters and state
internal/shared/ helpers the adapters share
internal/remend/ repair for markdown that is still streaming

internal/ is for this module only.

State

chat.StateAdapter stores keys, lists, locks, a per-thread queue, and subscriptions.

statememory keeps that data in memory. statepg keeps it in Postgres. You supply a *pgxpool.Pool. You run statepg.Schema yourself. This package does not create tables. Disconnect keeps the rows. It does not close your pool.

Platforms

Slack, GitHub, and Linear each implement chat.Adapter. Extra behavior is its own interface, such as chat.Streamer.

HandleWebhook checks the platform signature before it calls you. The Slack client refuses a response_url or a file URL on any other host.

GitHub uses one installation. Linear uses agent sessions. PORTING.md lists what this port left out.

Tests

go test ./...

The Postgres conformance test runs when TEST_DATABASE_URL is set. Otherwise that test skips.

Porting

PORTING.md lists the upstream pins and how this port differs.

If you bump vercel/chat or remend, or you add one named adapter, follow .claude/skills/porting/SKILL.md.

License

Apache License 2.0. See LICENSE.

The Chat SDK port is derived from MIT-licensed code. internal/remend is derived from Apache-2.0 code. Both notices are in NOTICE.