Deployment

Deploying an Agentic Function compiles it into an immutable version and exposes it as an authenticated HTTP endpoint.

The run API

An Agentic Function answers at a stable path keyed by its slug — POST /v1/run/{slug}. There is no version in the URL: the endpoint always runs the active deployment, so promoting or rolling back a version never changes the call:

curl -X POST https://api.fnai.dev/v1/run/classify \
  -H "Authorization: Bearer $FN_KEY" \
  -H "Content-Type: application/json" \
  -d '{"input": {"ticket": "…"}}'

To discover what the active deployment accepts and returns, ask for its contract — GET /v1/run/{slug}/contract.

The response is your typed output under output, plus a meta block:

{
  "status": "success",
  "output": {
    "category": "billing",
    "priority": "high",
    "confidence": 0.94
  },
  "meta": {
    "version": "v3",
    "latency_ms": 142,
    "cost_usd": 0.003,
    "tokens": 1840,
    "trace_id": "run_8f3c2a1d"
  }
}

status is success or failed; on a failure the reason is in error. Note that an execution failure is still a 200 — the HTTP status covers API-level problems (401 bad key, 404 unknown or undeployed Agentic Function, 422 input that doesn't match the contract, 504 execution timeout), so check status, not just the response code. meta.trace_id addresses the full run — pass it to fn logs or the API to replay exactly what happened.

Authentication

Requests are authenticated with a bearer token. Create scoped API keys per environment in your dashboard, and pass them as Authorization: Bearer <key>. Keys can be restricted to specific Agentic Functions.

Environments

A deploy targets a named environment — typically development, staging, and production. Each environment keeps its own version history and aliases, so shipping to staging never touches production traffic.

Aliases & rollback

Because the endpoint addresses the Agentic Function, not a version, promoting and rolling back are pointer moves behind a call that never changes:

fn promote classify --to v3
fn rollback classify --to v2

Callers keep hitting POST /v1/run/classify throughout; meta.version in the response tells you which version actually answered.

Rollback is instant because every version already exists; you are only moving a pointer.