Backend Deployment for Development¶

The recommended way to run Field-TM is with Docker.

You can also develop on your local machine outside of Docker, see below.

NOTE: If you haven't yet downloaded the Repository and setup your local environment, please check the docs here.

Now let's get started

1. Start the API with Docker¶

The easiest way to get up and running is by using the Field-TM Docker deployment. Docker creates a virtual environment, isolated from your computer's environment, installs all necessary dependencies, and creates a container for each the database, the api, and the frontend. These containers talk to each other via the URLs defined in the docker-compose file and your env file.

You will need to Install Docker and ensure that it is running on your local machine.
From the command line: navigate to the top level directory of the Field-TM project.
From the command line run: docker compose pull. This will pull the latest container builds from main branch.
Make sure you have a .env file with all required variables, see here.
Once everything is pulled, from the command line run: docker compose up -d api
If everything goes well you should now be able to navigate to the project in your browser: http://api.fmtm.localhost:7050/docs

Note: If that link doesn't work, check the logs with docker compose logs api. Note: the database host fmtm-db is automatically resolved by docker compose to the database container IP.

Bundled ODK Central¶

Field-TM uses ODK Central to store ODK data.
To facilitate faster development, the Docker setup includes a Central server.
The credentials are provided via the .env file, and the default URL to access Central from within containers is: https://odkcentral:8443.

Alternatively, you may provide credentials to an external Central server in the .env.

To run the local development setup without ODK Central (use external server):

dc --profile no-odk up -d

# Or via Just
just start without-central

2. Start the API without Docker¶

To run Field-TM without Docker, you will need to start the database, then the API.
First start a Postgres database running on a port on your machine.
- The database must have the Postgis extension installed.
After starting the database, from the command line:

Navigate to the backend directory under src/backend.
Install uv via the official docs
Install backend dependencies with uv: uv sync
Run the Fast API backend with: uv run uvicorn app.main:api --host 0.0.0.0 --port 8000

The API should now be accessible at: http://api.fmtm.localhost:7050/docs

Backend Tips¶

Database Migration¶

Creating Migration Files¶

Migrations can be written to src/backend/migrations.
Each file must be an SQL script that is:
- Idempotent: can be run multiple times without consequence.
- Atomic: Run within a BEGIN/COMMIT transaction.
Migrations must also include an equivalent revert migration under: src/backend/migrations/revert

Applying Migrations¶

Should occur automatically as part of the docker compose stack (migration service).
To run manually:

docker compose up -d migrations

# Or via Just
just migrate

The Task Scheduler¶

The backend runs a lightweight scheduling service via cron.
The scripts called and intervals can be found in the compose.yaml scheduler service.
As of 21th April 2025, we run:

# Task unlocking every 3hrs
* */3 * * * /opt/scheduler/unlock_tasks.py

# Check inactive users every Sunday 00:00
0 0 * * 0 /opt/scheduler/inactive_users.py

# Run project stats script every 10 mins
*/10 * * * * /opt/scheduler/project_stats.py

Type Checking¶

It is a good idea to have your code 'type checked' to avoid potential future bugs.
To do this, install pyright (VSCode has an extension).

Interactive Debugging¶

The local version of the backend API that runs in compose.yaml includes the debugpy package and a port bind to 5678.
This means you should be able to simply click the 'debugger' toolbar in VSCode, then 'Remote - Server Debug'.
When you add breakpoints to the code, the server should pause here to allow you to step through and debug code.
The configuration for this is in .vscode/launch.json.

Running Tests¶

To run the backend tests locally, run:

docker compose run --rm api pytest

# Or via Just
just test backend

To assess coverage of tests, run:

docker compose run --rm --entrypoint='sh -c' api \
  'coverage run -m pytest && coverage report -m'

# Or via Just
just test coverage

To assess performance of endpoints:

We can use the pyinstrument profiler.
While in debug mode (DEBUG=True), access any endpoint.
Add the ?profile=true arg to the URL to view the execution time.

Debugging osm-fieldwork¶

osm-fieldwork is an integral package for much of the functionality in Field-TM.

Creating a new release during development may not always be feasible.

A development version of osm-fieldwork can be mounted into the Field-TM container via bind mount.
Clone the osm-fieldwork repo to the same root directory as Field-TM.
Uncomment the line in compose.yaml

- ../osm-fieldwork/osm_fieldwork:/opt/python/lib/python3.12/site-packages/osm_fieldwork

Run the docker container with your local version of osm-fieldwork.
Code changes to osm-fieldwork should be reflected immediately. If they are not, run: docker compose restart api.

Note: this is useful for debugging features during active development.

Accessing S3 Files use s3fs¶

The s3fs tool allows you to mount an S3 bucket on your filesystem, to browse like any other directory.

Create a credentials file:

# Replace ACCESS_KEY_ID and SECRET_ACCESS_KEY
echo ACCESS_KEY_ID:SECRET_ACCESS_KEY > ${HOME}/.passwd-s3fs
chmod 600 ${HOME}/.passwd-s3fs

Mount local S3 using Just¶

just mount-s3

Mount S3 manually¶

Install s3fs:

sudo apt update
sudo apt install s3fs

Mount your bucket:

If you wish for this to be permanent, see below.

sudo mkdir /mnt/fmtm/local
sudo chown $(whoami):$(whoami) /mnt/fmtm/local
s3fs fmtm-data /mnt/fmtm/local \
  -o passwd_file=/home/$(whoami)/s3-creds/fmtm-local \
  -o url=http://s3.fmtm.localhost:7050 \
  -o use_path_request_style

Access the files like a directory under: /mnt/fmtm/local.

To mount permanently, add the following to /etc/fstab:

fmtm-data /mnt/fmtm/local fuse.s3fs _netdev,allow_other,\ use_path_request_style,passwd_file=/home/USERNAME/s3-creds/fmtm-local,\ url=http://s3.fmtm.localhost:7050 0 0

Note: you should replace USERNAME with your linux username.

Running JOSM in the dev stack¶

Run JOSM with Field-TM via Just:

just start josm

This adds JOSM to the docker compose stack for local development.

You can now call the JOSM API from Field-TM and changes will be reflected in the GUI.

Debugging ODK forms when running on localhost¶

ODK Collect requires an externally accessible instance of Central.
To achieve this for local development / debugging, a good solution is Cloudflare tunnelling (alternative to Ngrok).
There is a helper script to do this automatically for you:
```
just start tunnel
```

Once started, use the output ODK Central URL from the terminal during project creation. The QRCode should now work in ODK Collect.

The credentials for the local ODK Central instance are: Username: admin@hotosm.org Password: Password1234

Creating projects via the API¶

Field-TM supports API Keys, meaning in theory an external system could be used to create projects and call API endpoints, using the key.

1. Create an API key¶

Log into Field-TM as you the user you wish to use.
The user must have organization manager permission for creating new projects.
Generate an API key by accessing the following endpoint in the same browser you logged in as:

/integrations/api-key

Save the API key somewhere safe! The key can access all your data in Field-TM!
For any API call you make in the next section, ensure to set the x-api-key header. See the example in the next section!

2. Create project metadata¶

The metadata for a project must be created first.

!!! note This step assumes you already have an organization and connected ODK Central server configured. See here

To create a project you will need the following:
- Project name, description, instructions.
- The ID of the organization you manage.
  - Visit /auth/me while logged in to retrieve this.
- A GeoJSON of the area you wish to map.

See further details of the exact endpoint requirements here

Post the JSON data to the following endpoint: /projects?org_id=xxx

import os
import requests

FMTM_API_DOMAIN = os.getenv("FMTM_API_DOMAIN")
FMTM_API_KEY = os.getenv("FMTM_API_KEY")

response = requests.get(
  f"{FMTM_API_DOMAIN}/auth/me",
  headers={"x-api-key": FMTM_API_KEY},
)
org_id = response.json()["orgs_managed"][-1]

project_data = {
  "name": "your new project",
  "short_description": "short details here",
  "description": "long details here",
  "per_task_instructions": "user mapping instructions here",
  "outline": {
      "coordinates": [
          [
              [85.317028828, 27.7052522097],
              [85.317028828, 27.7041424888],
              [85.318844411, 27.7041424888],
              [85.318844411, 27.7052522097],
              [85.317028828, 27.7052522097],
          ]
      ],
      "type": "Polygon",
  },
  "primary_geom_type": "POINT",
  "new_geom_type": "POINT",
  "task_split_type": "CHOOSE_AREA_AS_TASK",
  "hashtags": ["hashtag1", "hashtag2"],
  "visibility": "PRIVATE",
}

response = requests.post(
  f"{FMTM_API_DOMAIN}/projects?org_id={org_id}",
  headers={"x-api-key": FMTM_API_KEY},
  json=project_data,
)

project_id = response.json().id
print(project_id)

A successful POST will return a project_id, which you should save for later steps.

3. Populate the tasks¶

Task splitting can be done via multiple APIs.
- By square: /projects/split-by-square.
- By splitting algorithm: /projects/split-by-sql.

For projects that require no task splitting, simply pass the AOI as the task area: /projects/xxx/upload-task-boundaries

import json

task_geojson = json.dumps(
  {
    "coordinates": [
        [
            [85.317028828, 27.7052522097],
            [85.317028828, 27.7041424888],
            [85.318844411, 27.7041424888],
            [85.318844411, 27.7052522097],
            [85.317028828, 27.7052522097],
        ]
    ],
    "type": "Polygon",
  }
).encode("utf-8")

task_geojson_file = {
    "task_geojson": (
        "file.geojson",
        BytesIO(task_geojson).read(),
    )
}

response = requests.post(
    f"{FMTM_API_DOMAIN}/projects/{project_id}/upload-task-boundaries",
    headers={"x-api-key": FMTM_API_KEY},
    files=task_geojson_file,
)

print(response.json())

4. Submit the data you wish to map (optional)¶

from io import BytesIO

with open("/path/to/your/data.geojson", "rb") as f:
    data_extracts = BytesIO(json.dumps(json.load(f)))

    data_extract_file = {
        "data_extract_file": (
            "file.geojson",
            data_extracts.read(),
        )
    }

response = requests.post(
    f"{FMTM_API_DOMAIN}/projects/{project_id}/upload-data-extract",
    headers={"x-api-key": FMTM_API_KEY},
    files=data_extract_file,
)

print(response.json())

5. Generate the final project data¶

For this step you need the XLSForm you wish to use for the survey.
- Validate the form via this link first.

from io import BytesIO
from pathlib import Path

xlsform_file = Path("/path/to/your/form.xls")
with open(xlsform_file, "rb") as xlsform_data:
    xlsform_obj = BytesIO(xlsform_data.read())

xform_file = {
    "xlsform": (
        "form.xls",
        xlsform_obj,
    )
}
response = requests.post(
    f"{FMTM_API_DOMAIN}/projects/{project_id}/generate-project-data",
    headers={"x-api-key": FMTM_API_KEY},
    files=xform_file,
)

You should have a project you can now access at:

https://the.field.tm.domain/projects/{project_id}