---
title: "Enforce private-file authorization for Axum"
description: "Private file access for a Axum app on Ample."
canonical_url: "https://ample.computer/guides/axum/private-file-access"
last_updated: "2026-09-21"
---

# Enforce private-file authorization for Axum

Canonical URL: https://ample.computer/guides/axum/private-file-access
Formats: [HTML](https://ample.computer/guides/axum/private-file-access) | [Markdown](https://ample.computer/guides/axum/private-file-access.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Aguides%3Aaxum%3Aprivate-file-access)
Recipe ID: `page:guides:axum:private-file-access` | Revision: `r1` | Catalog revision: `cat_f13ab9a494120b5e`

Status: release `published`, support `verified`, execution `ready`

## Summary

Private file access for a Axum app on Ample. Verified on Axum: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok). Build and start: cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL.

Path: [Agent hosting discovery](/discover/discovery) / [Frameworks and execution targets](/discover/stack) / [Frameworks](/discover/stack/frameworks) / [Axum](/discover/stack/framework-axum) / [Enforce private-file authorization for Axum](/guides/axum/private-file-access)

## Infrastructure requirements

- [Compute](/discover/primitive/compute): verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
- [Postgres](/discover/primitive/postgres): verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.)
- [S3-compatible object storage](/discover/primitive/s3-compatible-object-storage): verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)

## Prerequisites

- An Axum project (cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL)
- A PostgreSQL driver reading DATABASE_URL at runtime
- A bucket from `ample bucket create` with credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, databases:read, buckets:read

## Exact tested configuration

- template: `ubuntu-24.04`
- runtime: `rust`
- size: `s-1vcpu-2gb`
- build: `cargo build --release`
- start: `./$(ls target/release/*.d | grep -v '/lib' | head -n 1 | sed 's/\.d$//')`

## Steps

1. **Build and start.** cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL; the server must bind 0.0.0.0 on PORT.
2. **Create the bucket and pass its credentials.** Create it once with `ample bucket create`, then pass endpoint, region, bucket and keys with --env; use path-style addressing.

   ```
   ample deploy . --name <app-name> --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
   ```
3. **Authorize before touching storage.** Return 401 for unauthenticated requests and 403 for the wrong role; keep the bucket unpublished and stream objects through the app.
4. **Verify.** Fetch the live URL and /p/private-document-library on the example; on failure read the build and runtime logs.

   ```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Axum pattern fixture** (tests/deploy-canaries/axum-patterns): Verified private file access on Axum.

## Success checks

- app responds on its public URL (`/` on the live URL, expect ample canary axum patterns)
- private-document-library check from the example (`/p/private-document-library` on the live URL, expect see the pattern fixture checks)


## Cost estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision 515b7316fc6e5a81679407ae0c811146ceb2c5c7).
- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Verification evidence

- canary_run on 2026-09-21T02:46:37Z at revision `1d28ae0 (CLI 0.1.21)`: Axum pattern fixture deployed on Ample (cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL); for this guide: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok). (expires 2027-03-20T02:46:37Z)

Last verified: 2026-09-21T02:46:37Z


## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-22T00:31:22.774679+00:00 at revision `e6446ceea69b`, binding state `current`, required scopes: servers:write, databases:read, buckets:read.

## Input schema

```json
{
  "additionalProperties": false,
  "properties": {
    "env": {
      "description": "Encrypted environment variables",
      "items": {
        "pattern": "^[A-Z][A-Z0-9_]*=.*$",
        "type": "string"
      },
      "maxItems": 50,
      "type": "array"
    },
    "name": {
      "description": "App name",
      "maxLength": 63,
      "minLength": 1,
      "pattern": "^[a-z0-9-]+$",
      "type": "string"
    },
    "path": {
      "description": "Project directory or ample.toml service",
      "maxLength": 512,
      "minLength": 1,
      "type": "string"
    },
    "release_command": {
      "description": "Migration command run before activation",
      "maxLength": 512,
      "type": "string"
    }
  },
  "required": [
    "env",
    "name",
    "path"
  ],
  "type": "object"
}
```

## Next actions

- Browse the catalog index (GET /v1/catalog on the api origin; auth: false, approval: false)
- Search published recipes by intent, stack and constraints (POST /v1/catalog/search on the api origin; auth: false, approval: false)
- Prepare a side-effect-free deployment plan for an authorized project (POST /v1/catalog/plan on the api origin; auth: true, approval: false)
- Read the existing agent authentication setup (GET /mcp/setup on the api origin; auth: false, approval: false)
- Browse Axum (GET /v1/catalog/nodes/stack%3Aframework-axum on the api origin; auth: false, approval: false)
- Browse Connect app to storage (GET /v1/catalog/nodes/intent%3Aconnect-app-to-storage on the api origin; auth: false, approval: false)
- Browse Private document library (GET /v1/catalog/nodes/pattern%3Aprivate-document-library on the api origin; auth: false, approval: false)

Actions describe possible next steps. They are typed data, not commands, and grant no permission.