OutboundSync API

When to use this guide: You want a programmatic way to verify an OutboundSync API key, inspect which CRM connections it can access, check whether your sync pipeline is ready, or help an AI coding assistant build against OutboundSync.

The OutboundSync API is the developer surface for OutboundSync itself. It is separate from the Smartlead, Instantly, EmailBison, HeyReach, and other platform API keys you save so OutboundSync can read from those tools.

The API is in Beta. Introspection endpoints (/me, /account/status, /connections, /sources) are stable and read-only. Webhooks and the event log add the first write-capable routes. We may add fields and endpoints as the surface grows.

Start here

Pick the path that matches where you are:

Try the API Send live requests from these docs. Start with a keyless health check, then paste a key for your account.

Creating API keys Create, store, rotate, revoke, and scope OutboundSync API keys from the admin app.

Platform health endpoints Public /health endpoints to monitor OutboundSync availability — no API key required.

API v1 reference Full contract for every account endpoint, vocabulary, status codes, and the security model.

OutboundSync webhooks Register Sync Monitoring webhooks, verify signatures, and understand delivery retries.

OutboundSync Agent Skills Install public Agent Skills for launch readiness, CRM analysis, copy, and deliverability.

Errors and rate limits Handle invalid keys, disabled API access, rate limits, and retry behavior.

Machine-readable contract (OpenAPI 3.1):

Base URL and authentication

Account endpoints live under /api/v1 and use Bearer authentication:

https://app.outboundsync.com/api/v1

Authorization: Bearer osapi_<your-secret>

Platform health endpoints (/health/live, /health/ready) and OpenAPI discovery do not require a key. See Platform health endpoints.

What you can call

The public API separates sources → destinations from webhooks: a source is an inbound URL you paste into a sequencer (UI: Sources), a destination is either a Forwarding destination URL or a Reply relay that CC’s a sales rep on prospect replies, and webhooks are OutboundSync-emitted Sync Monitoring events delivered to endpoints you register (UI: Webhooks).

Endpoint	Auth	Purpose
`GET /health/live`	None	Is the platform process up?
`GET /health/ready`	None	Can it receive and sync events right now?
`GET /api/v1/openapi.json`	None	OpenAPI 3.1 document (JSON).
`GET /api/v1/openapi.yaml`	None	OpenAPI 3.1 document (YAML).
`GET /api/v1/me`	Bearer	Validate the key, list accessible CRM connections, discover related endpoints via `links`.
`GET /api/v1/account/status`	Bearer	Pipeline readiness with `blockers[]` and `warnings[]`.
`GET /api/v1/account/metrics`	Bearer	Request, sync, and destination-delivery counts for a `from`/`to` date range (max 31 days).
`GET /api/v1/connections`	Bearer	CRM connections with OAuth status and plan capabilities.
`GET /api/v1/sources`	Bearer	Inbound paste URLs, platform config, and destination bindings.
`GET /api/v1/requests`	Bearer	Inbound receipts for a `from`/`to` date range (max 31 days).
`GET /api/v1/syncs`	Bearer	CRM sync attempts for a `from`/`to` date range (max 31 days).
`POST /api/v1/syncs/:id/retry`	Bearer (`write`)	Enqueue a HubSpot/Salesforce Error sync retry.
`GET /api/v1/destinations`	Bearer	Forwarding destination catalog (list + get).
`GET /api/v1/destinations/:id/deliveries`	Bearer	Outbound delivery attempts for one forwarding destination.
`GET /api/v1/deliveries`	Bearer	Account-wide destination delivery export for a `from`/`to` date range.
`POST /api/v1/destinations/:id/deliveries/:deliveryId/replay`	Bearer (`write`)	Enqueue a replay of one destination delivery.
`GET /api/v1/destinations/reply-relays`	Bearer	Reply relay catalog for accessible connections.
`/api/v1/webhooks`	Bearer	Register and manage Webhooks (Sync Monitoring).
`/api/v1/events`	Bearer	Queryable platform event log and delivery history.

Full request and response shapes live in the API v1 reference. Use Try the API for health, account, and webhook endpoints from the browser when OpenAPI lists them; fetch the OpenAPI URLs directly for discovery (they are not in the console menu). How-to for Sync Monitoring: OutboundSync webhooks.

Authentication flow

Sequence diagram showing a client calling GET /api/v1/me with a Bearer API key, OutboundSync applying an IP rate limit, validating the key hash, resolving API-enabled CRM connections, and returning a MeResponse. — How OutboundSync validates an API key before returning account and connection details.

Quick test

Prefer the in-docs console when you can — Try the API needs no tooling. Use GET /api/v1/me as the first authenticated request. A successful response proves the key is valid and shows whether it is account-wide or scoped to one CRM connection.

curl 'https://app.outboundsync.com/api/v1/me' \
  -X GET \
  -H 'Authorization: Bearer osapi_<your-secret>'

Ask an AI coding assistant

For how the API, Skills, and Sync Monitoring Webhooks fit one agentic loop, start at AI and Agents.

For API vocabulary and routing, launch readiness, or Sync Monitoring from an agent, use the public Agent Skills — start with Install skills instead of pasting a long rule:

npx skills add outboundsync/skills --skill api -g
npx skills add outboundsync/skills --skill preflight -g
npx skills add outboundsync/skills --skill sync-monitoring -g

See API, Preflight, and Sync monitoring.

For a quick key check only, paste this into Cursor, Claude Code, Codex, or another coding assistant after you create an API key:

Verify my OutboundSync API key against GET https://app.outboundsync.com/api/v1/me.
Docs: https://outboundsync.com/docs/api/v1/
OpenAPI: https://app.outboundsync.com/api/v1/openapi.json
Use Bearer authentication. Parse the connections array and tell me which CRM connections this key can access.

OutboundSync docs pages also have mirrored Markdown endpoints under /content/docs/...md/, so coding assistants can retrieve the same reference content in a machine-readable form.