HTTP API Overview

Introduction

The Loom HTTP API provides programmatic access to the Loom platform, enabling you to build custom integrations, automate workflows, and create alternative clients for the AI-powered coding agent.

Base URL

All API requests are made to:

https://loom.ghuntley.com

For self-hosted deployments, replace with your instance URL.

Authentication

The Loom API supports multiple authentication methods:

Session Cookies

Web clients authenticate using HttpOnly session cookies set after OAuth or magic link login. The cookie name is configurable (default: loom_session).

API Keys

For programmatic access, use API keys with the Authorization header:

curl -H "Authorization: Bearer loom_sk_..." \
  https://loom.ghuntley.com/api/threads

API keys can be created via the dashboard or API and support scoped permissions.

WebSocket Tokens

For WebSocket connections, obtain a short-lived token from /auth/ws-token (expires in 30 seconds, single-use):

curl -H "Cookie: loom_session=..." \
  https://loom.ghuntley.com/auth/ws-token

Send the token in the WebSocket first message:

{"type": "auth", "token": "ws_..."}

Request Format

All POST/PUT requests accept JSON payloads with Content-Type: application/json:

curl -X POST https://loom.ghuntley.com/api/threads/abc123 \
  -H "Authorization: Bearer loom_sk_..." \
  -H "Content-Type: application/json" \
  -d '{"id": "abc123", "title": "My Thread", ...}'

Response Format

All responses return JSON with appropriate HTTP status codes:

Success Response (200 OK)

{
  "id": "thread_abc123",
  "title": "Example Thread",
  "created_at": "2026-03-03T12:00:00Z"
}

Error Response (4xx/5xx)

{
  "error": "not_found",
  "message": "Thread not found",
  "server_version": "1.0.0",
  "client_version": null
}

Pagination

List endpoints support offset-based pagination:

limit

integer

default:"50"

Maximum number of results to return

offset

integer

default:"0"

Number of results to skip

Example:

curl "https://loom.ghuntley.com/api/threads?limit=20&offset=40"

Response includes pagination metadata:

{
  "threads": [...],
  "total": 127,
  "limit": 20,
  "offset": 40
}

Optimistic Concurrency

Thread operations support optimistic locking via the If-Match header:

curl -X PUT https://loom.ghuntley.com/api/threads/abc123 \
  -H "If-Match: 42" \
  -H "Content-Type: application/json" \
  -d '{"id": "abc123", "version": 42, ...}'

If the version doesn’t match, the API returns 409 Conflict:

{
  "error": "version_conflict",
  "message": "Expected version 42, but current version is 43"
}

Rate Limiting

LLM proxy endpoints may return 503 Service Unavailable with retry information:

{
  "error": "rate_limited",
  "message": "LLM rate limited; retry after 30 seconds"
}

Server-Sent Events (SSE)

Streaming endpoints use SSE with event: llm headers:

curl -N https://loom.ghuntley.com/proxy/anthropic/stream \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-sonnet-4", "messages": [...]}'

Events:

event: llm
data: {"type":"text_delta","content":"Hello"}

event: llm
data: {"type":"completed","response":{...}}

WebSocket Connections

Real-time communication uses WebSocket endpoints:

Terminal attach: wss://loom.ghuntley.com/api/weaver/{id}/attach
Session streaming: wss://loom.ghuntley.com/api/ws/sessions/{id}

Authenticate via first message using a WebSocket token from /auth/ws-token.

Status Codes

Code	Meaning	Description
200	OK	Request succeeded
201	Created	Resource created successfully
204	No Content	Resource deleted successfully
400	Bad Request	Invalid request parameters
401	Unauthorized	Authentication required
403	Forbidden	Insufficient permissions
404	Not Found	Resource does not exist
409	Conflict	Version mismatch (optimistic locking)
500	Internal Server Error	Server-side error
503	Service Unavailable	Upstream service unavailable

SDKs and Libraries

Official SDKs:

Rust: loom-common-core (built-in)
TypeScript: @loom/client (web/Node.js)
VS Code Extension: Uses TypeScript client

Next Steps

Authentication Endpoints - OAuth, magic links, and device code flow
Thread Endpoints - Manage conversation threads
Weaver Endpoints - Provision ephemeral compute environments
LLM Proxy Endpoints - Server-side LLM completions

HTTP API

CLI Commands

HTTP API Overview

Introduction

Base URL

Authentication

Session Cookies

API Keys

WebSocket Tokens

Request Format

Response Format

Success Response (200 OK)

Error Response (4xx/5xx)

Optimistic Concurrency

Rate Limiting

Server-Sent Events (SSE)

WebSocket Connections

Status Codes

SDKs and Libraries

Next Steps

Build docs developers (and LLMs) love

HTTP API

CLI Commands

Documentation Index

​Introduction

​Base URL

​Authentication

​Session Cookies

​API Keys

​WebSocket Tokens

​Request Format

​Response Format

​Success Response (200 OK)

​Error Response (4xx/5xx)

​Pagination

​Optimistic Concurrency

​Rate Limiting

​Server-Sent Events (SSE)

​WebSocket Connections

​Status Codes

​SDKs and Libraries

​Next Steps

Build docs developers (and LLMs) love

Introduction

Base URL

Authentication

Session Cookies

API Keys

WebSocket Tokens

Request Format

Response Format

Success Response (200 OK)

Error Response (4xx/5xx)

Pagination

Optimistic Concurrency

Rate Limiting

Server-Sent Events (SSE)

WebSocket Connections

Status Codes

SDKs and Libraries

Next Steps