> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rcintell.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Which API to use

> Client-facing lookups for billing, policy, payment, and agents — not admin ingest

Use this page to pick a REST family. Parameter-level detail lives in **API Reference**. Trial keys (`kp_test_`) can call the read surface below. Agents and some writes need a live key.

Admin ingest (`POST /v1/policy/parse`, catalog sync, bootstrap) is not documented here. Those routes are for the website and operators, not client integrations.

## Start here

| Job                                  | Call                                                             | Guide                                                                  |
| ------------------------------------ | ---------------------------------------------------------------- | ---------------------------------------------------------------------- |
| Cited payer policy (NCD / LCD / MAC) | `GET /v1/policies`                                               | [Payer policies](/docs/policies)                                       |
| 340B manufacturer access             | `GET /v1/340b/restrictions/resolve`                              | [340B](/docs/policy-340b)                                              |
| Prior auth required?                 | `GET /v1/prior-auth/check`                                       | [Prior authorization](/docs/prior-auth)                                |
| Who is this payer?                   | `GET /v1/directory/payers/` (public)                             | [Payer network](/docs/network)                                         |
| Full billing context from a CCN      | `POST /v1/knowledge/resolve`                                     | [Knowledge resolve](/docs/knowledge/resolve)                           |
| Expected Medicare payment            | `POST /v1/knowledge/payment-calc` or `GET /v1/fee-schedules/...` | [Fee schedules](/docs/fee-schedules)                                   |
| NCCI units / bundling                | `GET /v1/ncci/...`                                               | [NCCI](/docs/knowledge/ncci)                                           |
| Pre-visit PA + NCCI + payment        | `POST /v1/encounter/check`                                       | [Encounter check](/docs/encounter)                                     |
| Coding or appeal research            | `POST /v1/agents/...` then poll or `callback_url`                | [AI agents](/docs/agents/overview) · [Agent callbacks](/docs/webhooks) |

## Policy and coverage

| Endpoint                                          | When to use                                                    |
| ------------------------------------------------- | -------------------------------------------------------------- |
| `GET /v1/policies`                                | Versioned, geo-scoped cited policy for a payer + code          |
| `GET /v1/policies/changes`                        | Document-grain policy diffs (pull). Empty until versions exist |
| `GET /v1/340b/manufacturers`                      | Latest approved 340B manufacturer policy cards                 |
| `GET /v1/340b/restrictions/resolve`               | Fail-closed access status for an entity / NDC / manufacturer   |
| `GET /v1/340b/changes`                            | Manufacturer policy change feed                                |
| `GET /v1/340b/entities/{id}`                      | OPAIS covered entity + contract pharmacies                     |
| `POST /v1/340b/portfolio/check`                   | Batch resolve a formulary × sites                              |
| `GET /v1/prior-auth/check`                        | CRD-style PA determination                                     |
| `GET /v1/prior-auth/documentation/{payer}/{code}` | Documents the payer wants on the PA                            |
| `GET /v1/directory/payers/`                       | Public directory (no API key)                                  |
| `GET /v1/payers/{slug}`                           | Authenticated payer profile, filing, appeals                   |

## Knowledge, codes, and payment

| Endpoint                            | When to use                        |
| ----------------------------------- | ---------------------------------- |
| `POST /v1/knowledge/resolve`        | L1–L6 stack from a CCN             |
| `POST /v1/knowledge/billing-guide`  | Form, TOB, modifiers               |
| `POST /v1/knowledge/payment-calc`   | MPFS-style estimate at a facility  |
| `GET /v1/fee-schedules/mpfs/{code}` | Professional RVUs                  |
| `GET /v1/fee-schedules/opps/{code}` | Hospital outpatient APC            |
| `GET /v1/fee-schedules/dme/{code}`  | DMEPOS by state                    |
| `GET /v1/fee-schedules/lab/{code}`  | CLFS                               |
| `GET /v1/ncci/validate`             | Can these two codes bill together? |
| `GET /v1/codes/search`              | CPT/HCPCS lookup                   |
| `GET /v1/npi/search`                | NPPES provider search              |
| `GET /v1/drugs/ndc/search`          | OpenFDA NDC                        |

## Agents (async)

| Endpoint                            | When to use                          |
| ----------------------------------- | ------------------------------------ |
| `POST /v1/agents/code-research`     | Which code, documentation, modifiers |
| `POST /v1/agents/medical-necessity` | NCD/LCD necessity write-up           |
| `POST /v1/agents/denial-resolution` | CARC/RARC + appeal strategy          |
| `GET /v1/agents/jobs/{job_id}`      | Poll until `completed` or `failed`   |

`POST /v1/encounter/check` is the pre-visit bundle — see [Encounter check](/docs/encounter), not an agent.

Pass `callback_url` + `callback_secret` on submit instead of polling. See [Agent callbacks](/docs/webhooks).

Register the facility first (`POST /v1/facilities`) if the route needs a CCN on your tenant.

## Not in client docs

These exist on the platform and stay in the internal OpenAPI snapshot. They are not part of client onboarding:

* Admin bootstrap, key minting, catalog sync
* Policy PDF parse / retrieve (`X-Admin-Secret`)
* ML feature dumps for external engines
* Internal audit-event APIs