CContentReach

Documentation

This page is for the human setting things up. If you're an agent, or building integration code, read llms.txt (quick reference) or llms-full.txt (complete spec) instead — same information, machine-oriented format.

Getting started

1
Sign in
Go to /auth/sign-in with your email — you'll get a one-time link, no password to set.
2
Connect LinkedIn
From /settings, click “Connect LinkedIn” and authorize on LinkedIn's own consent screen. This is the account posts will publish to.
3
Add Balance
Top up via Stripe when it's live, or use the manual test-balance field in settings while it isn't. Posts are prepaid — no subscription.
4
Generate an API key
From settings, create a key scoped to the LinkedIn account(s) you want it to reach, with an optional spend cap. The full key is shown exactly once — save it now.
5
Give the key to your agent
Pass it as a Bearer token over REST, or as CONTENTREACH_API_KEY to the MCP server. Same key works for both.

Publish a post

One call, whichever transport your agent speaks. Both are capability-equivalent — nothing is REST-only or MCP-only.

REST

POST /v1/posts

curl https://contentreach.io/api/v1/posts \
  -H "Authorization: Bearer cr_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "linked_account": "la_9f2...",
    "content": "Finished text, ready to publish."
  }'

# 201
{
  "id": "urn:li:share:...",
  "linked_account": "la_9f2...",
  "balance_cents": 1975
}

MCP

The hosted endpoint is https://contentreach.io/api/mcp (Streamable HTTP, stateless). Send your API key as a Bearer token on every request, exactly like REST. Two tools are registered:

publish_post — { linked_account, content }, equivalent to POST /v1/posts.
check_balance — no arguments, equivalent to GET /v1/balance.

For local development against a client like Claude Desktop, the source in mcp-server/ also runs standalone over stdio (npm run dev, with CONTENTREACH_API_KEY set) — same tools, same code, different transport.

Check balance

Pre-empt a 402 rather than react to one:

GET /v1/balance

curl https://contentreach.io/api/v1/balance \
  -H "Authorization: Bearer cr_live_..."

# 200
{ "balance_cents": 1975 }

Error codes

Every failure — REST or MCP — is { error: { code, message, retryable } }. Codes are stable; a code, once shipped, is never repurposed.

Code	HTTP	Meaning	Retryable
api_key.missing	401	No API key on the request.	No
api_key.invalid	401	Key is invalid, revoked, or unknown.	No
api_key.out_of_scope	403	Key isn't scoped to the requested Linked Account.	No
api_key.spend_cap_exceeded	402	Key has hit its own spend cap.	No
api_key.rate_limited	429	Too many requests for this key in the current window.	Yes
linked_account.session_expired	409	LinkedIn token expired or was revoked — reconnect via settings.	No
linked_account.not_found	404	linked_account ID doesn't match a connected account.	No
balance.insufficient	402	Not enough Balance for this post — top up and retry.	Yes
content.rejected	422	Content failed the pre-publish spam/gibberish check.	No
content.invalid	400	Request body is malformed (missing field, over length limit).	No
internal_error	500	Something broke on our end.	No

Limits

Rate limit: 60 requests/minute per API key, enforced durably (holds across every instance, not per-process). A 429 includes retryable: true and how long to wait.
Content length: 3,000 characters, LinkedIn's own practical limit for organic posts.
Content screening: posts are checked for mechanical spam/gibberish (long runs of a repeated character, more than 5 URLs) before they're charged for. This isn't a topic or toxicity filter — you and your agent are responsible for what gets posted.
Scope: LinkedIn personal profiles only, v1. Company/organization pages need LinkedIn's own Marketing Developer Platform approval, which isn't complete yet.

Pricing lives on the landing page — not duplicated here, since it's the one place the rate won't go stale in two locations.