# HTTP API Reference

This is the canonical public HTTP contract for Scriptorium.

Implemented route:

- `POST /v1/runs`

For CLI behavior, see [CLI reference](cli.md). For config and prompt/profile
file formats, see [Configuration reference](config.md).

## Base URL And Deployment

`scriptorium serve` listens on `server.addr` or `serve --addr`. The default is
`:8080`.

The route path is always:

```text
/v1/runs
```

The HTTP adapter has no built-in authentication or authorization. Deploy it
behind trusted network and authentication controls.

## Media Types

- Request body: JSON object.
- Response body: JSON object.
- Response `Content-Type`: `application/json`.

Requests are decoded as JSON regardless of the request `Content-Type` header.
There are no shared query parameters.

## Request Limits

HTTP limits are configured through `server.*` config fields or `serve` flags:

- `server.max_request_bytes`: encoded JSON request body limit, including inline input bodies.
- `server.max_artifact_bytes`: file artifact limit for HTTP `file` input references.
- `server.max_response_bytes`: encoded JSON response limit, including artifact body and optional raw output.

Each limit defaults to `16777216` bytes. `0` disables that limit.

## `POST /v1/runs`

Runs one prompt request and returns the generated artifact, validation result,
and metadata.

### Request Body

```json
{
  "prompt_id": "generic.markdown_summary",
  "profile_id": "local-fast",
  "prompt_version": "1.0.0",
  "inputs": {
    "transcript": {
      "type": "file",
      "uri": "./examples/fixtures/transcript.md"
    },
    "glossary": {
      "type": "inline",
      "body": "party:\n  - Rin"
    }
  },
  "vars": {
    "session_date": "2026-05-04"
  },
  "model": {
    "endpoint": "http://localhost:8000/v1",
    "model": "gpt-4o-mini",
    "temperature": 0,
    "max_tokens": 800,
    "top_p": 1,
    "timeout_seconds": 120,
    "service_tier": "priority",
    "reasoning_effort": "medium",
    "api_key_env": "SCRIPTORIUM_API_KEY",
    "extra_params": {
      "provider_option": "enabled"
    }
  },
  "include_raw_output": false
}
```

Request fields:

| Field | Required | Description |
| --- | --- | --- |
| `prompt_id` | yes | Prompt ID. Must not be blank. |
| `prompt_version` | no | Prompt version filter. |
| `profile_id` | no | Execution profile ID. If omitted, the prompt must define `default_profile`. |
| `inputs` | yes | Object mapping prompt input names to input references. Must contain at least one entry. |
| `vars` | no | Object mapping template variable names to string values. |
| `model` | no | Runtime model override object. |
| `include_raw_output` | no | When `true`, include `raw_model_output` in the response. |

Input reference fields:

| Field | Required | Description |
| --- | --- | --- |
| `type` | yes | `file` or `inline`. |
| `uri` | for `file` | File URI/path. |
| `body` | for `inline` | Inline artifact body. |

HTTP `file` references require `server.artifact_root` or `serve
--artifact-root`. Relative file URIs resolve against that root. Absolute file
URIs are accepted only when lexically inside the root. Relative traversal and
absolute paths outside the root return `400 artifact_not_allowed`.

The containment check is lexical and does not resolve symlinks. Symlinks inside
the artifact root are followed by the operating system, including symlinks that
point outside the root. Keep the artifact root narrow and not writable by
untrusted users.

Model override fields:

| Field | Description |
| --- | --- |
| `endpoint` | Runtime endpoint override. |
| `model` | Runtime model override. |
| `temperature` | Number in range `0..2`. Explicit `0` is an override. |
| `max_tokens` | Integer greater than or equal to `0`. Explicit `0` is an override. |
| `top_p` | Number in range `0..1`. Explicit `0` is an override. |
| `timeout_seconds` | Integer greater than or equal to `0`. Explicit `0` disables the outbound client timeout. |
| `service_tier` | Provider-specific request tier. |
| `reasoning_effort` | Provider-specific reasoning setting. |
| `api_key_env` | Name of an environment variable containing the API key. |
| `extra_params` | JSON-compatible provider-specific top-level request fields. |

Raw API-key values are not accepted in HTTP payloads. A field such as
`api_key` is rejected as unknown JSON.

`extra_params` keys must not be empty and must not collide with reserved
outbound fields: `model`, `session_id`, `messages`, `temperature`,
`max_tokens`, `top_p`, `service_tier`, `reasoning_effort`, or
`response_format`.

### Strict JSON Rules

Request decoding is strict:

- malformed JSON returns `400 invalid_json`
- unknown request fields return `400 invalid_json`
- unknown `inputs` item fields return `400 invalid_json`
- unknown `model` fields return `400 invalid_json`
- trailing JSON tokens after the request object return `400 invalid_json`
- request bodies above the configured limit return `413 request_too_large`

### Success Response

Status: `200 OK`

```json
{
  "artifact": {
    "name": "output",
    "content_type": "text/markdown",
    "body": "Generated content",
    "size": 17,
    "hash": "..."
  },
  "validation": {
    "status": "passed",
    "mode": "basic",
    "repair_attempts": 0,
    "is_valid": true
  },
  "metadata": {
    "run_id": "...",
    "prompt_id": "generic.markdown_summary",
    "prompt_version": "1.0.0",
    "prompt_hash": "...",
    "rendered_prompt_hash": "...",
    "selected_profile_id": "local-fast",
    "model_name": "gpt-4o-mini",
    "endpoint": "http://localhost:8000/v1",
    "model_params": {
      "endpoint": "http://localhost:8000/v1",
      "model": "gpt-4o-mini",
      "temperature": 0.2,
      "max_tokens": 500,
      "top_p": 1,
      "timeout_seconds": 90
    },
    "input_hashes": {
      "transcript": "..."
    },
    "usage": {
      "prompt_tokens": 11,
      "completion_tokens": 22,
      "total_tokens": 33,
      "cached_tokens": 0,
      "cache_write_tokens": 0
    },
    "start_time": "2026-05-04T12:00:00Z",
    "end_time": "2026-05-04T12:00:01Z",
    "duration_ms": 1000,
    "validation_mode": "basic",
    "validation_status": "passed",
    "repair_attempts_used": 0
  }
}
```

Response fields:

- `artifact`: generated output artifact.
- `validation`: validation result for the generated artifact.
- `metadata`: run and effective runtime metadata.
- `raw_model_output`: omitted unless `include_raw_output` is `true`.

`artifact.uri` is omitted when empty. `validation.errors` and
`validation.schema_path` are omitted when empty. `model_params.service_tier`,
`model_params.reasoning_effort`, `model_params.api_key_env`, and
`model_params.extra_params` are omitted when empty.

`metadata.usage.cached_tokens` and `metadata.usage.cache_write_tokens` are
always present as numbers. They are `0` when the provider omits compatible cache
usage fields or reports no cache activity.

### Validation Failure Response

Generated-content validation failures still return `200 OK`.

```json
{
  "validation": {
    "status": "failed",
    "mode": "json",
    "errors": ["invalid JSON: ..."],
    "repair_attempts": 0,
    "is_valid": false
  }
}
```

The response still includes `artifact` and `metadata`.

## Error Responses

Error body shape:

```json
{
  "error": {
    "code": "invalid_request",
    "message": "prompt_id is required"
  }
}
```

Current status/code mapping:

| Status | Code | Meaning |
| --- | --- | --- |
| `400` | `invalid_json` | Malformed JSON, unknown JSON field, or trailing JSON token. |
| `400` | `invalid_request` | Missing/invalid request fields or invalid runtime overrides. |
| `400` | `profile_required` | No `profile_id` and prompt has no `default_profile`. |
| `400` | `prompt_load_failed` | Prompt definition YAML/contract failed to load. |
| `400` | `profile_load_failed` | Profile YAML/contract failed to load, including raw `api_key`. |
| `400` | `artifact_not_allowed` | HTTP file refs are disabled or requested path is outside artifact root. |
| `400` | `artifact_read_failed` | Input artifact could not be read or input ref was unsupported/invalid. |
| `400` | `prompt_render_failed` | Prompt template rendering failed. |
| `400` | `api_key_env_missing` | Selected `api_key_env` variable is unset or empty. |
| `404` | `not_found` | Route path is unknown. |
| `404` | `prompt_not_found` | Prompt ID/version was not found. |
| `404` | `profile_not_found` | Profile ID was not found. |
| `405` | `method_not_allowed` | Method is not `POST` on `/v1/runs`. |
| `413` | `request_too_large` | Encoded JSON request body exceeds configured request limit. |
| `413` | `artifact_too_large` | HTTP file input artifact exceeds configured artifact limit. |
| `413` | `response_too_large` | Encoded JSON response exceeds configured response limit. |
| `500` | `validation_runtime_failed` | Validator runtime/schema loading failed. |
| `500` | `internal_error` | Unclassified server error. |
| `502` | `llm_failed` | Outbound model request failed. |

HTTP error messages are intentionally concise and do not include sensitive
internal causes.

## Retry And Idempotency

Scriptorium does not provide idempotency keys, pagination, caching headers, or
rate limiting.

Clients may retry transport failures or `5xx` responses when their surrounding
workflow can tolerate another model call. A retry can generate different output
and incur another provider request.