---
title: "Hooks Session Start"
method: POST
path: "/hooks/session-start"
---

# Hooks Session Start

`POST /hooks/session-start`

## Request

- Base URL: `https://usemeridian.us` (the document declares no server; this is the origin it was published from)
- URL: `https://usemeridian.us/hooks/session-start`
- Auth: none declared

Claude Code / Codex SessionStart hook.

Accepts {project_id, session_name?}. Calls start_session() and returns
{hookSpecificOutput: {additionalContext: "..."}} so Claude Code injects
the project context into the agent's initial context window automatically.

Hosted callers can authenticate with Authorization: Bearer sk_meridian_...
to route directly to their tenant DB. Local/browser-session behavior is
unchanged when no Bearer token is supplied.

## Request body

- object

## Response `200`

Successful Response

- object

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/usemeridian/apis/meridian.md) · [All operations](https://skmtc.dev/usemeridian/apis/meridian/llms.txt) · [OpenAPI document](https://skmtc.dev/usemeridian/apis/meridian/revisions/f37a894bd374?raw)