Configuration

jamb uses a two-level configuration model. Project-wide settings live in pyproject.toml under the [tool.jamb] section, controlling behavior like which documents require test coverage, matrix output format, and CI enforcement options. Per-document settings live in a .jamb.yml file inside each document directory, defining the document’s prefix, parent relationships, and UID formatting. The sections below describe both levels in detail.

Project Configuration (pyproject.toml)

jamb is configured in pyproject.toml under the [tool.jamb] section:

[tool.jamb]
test_documents = ["SRS"]
fail_uncovered = false
require_all_pass = true
software_version = "1.0.0"
exclude_patterns = []
trace_to_ignore = []

# Matrix output options (format inferred from extension)
test_matrix_output = "test-records.html"
trace_matrix_output = "traceability.html"
trace_from = "UN"
include_ancestors = true

Options Reference

test_documents

List of document prefixes that represent test specifications. These are the documents checked for test coverage.

Type: list[str]

Default: []

fail_uncovered

Fail the pytest session if any items in test_documents lack test coverage.

Type: bool

Default: false

require_all_pass

Require all linked tests to pass (not just exist) for an item to be considered covered.

Type: bool

Default: true

test_matrix_output

Output path for the test records matrix (test-centric view). Can be overridden with --jamb-test-matrix. Format is inferred from the file extension.

Type: str | null

Default: null

trace_matrix_output

Output path for the traceability matrix (requirement-centric view). Can be overridden with --jamb-trace-matrix. Format is inferred from the file extension.

Type: str | null

Default: null

exclude_patterns

Glob patterns for documents or items to exclude from processing.

Type: list[str]

Default: []

trace_to_ignore

Document prefixes to exclude from the “Traces To” column in the traceability matrix.

Type: list[str]

Default: []

software_version

Software version to display in the traceability matrix metadata. If not set, jamb auto-detects the version from [project].version in pyproject.toml, or from dynamic version files (hatch-vcs, setuptools_scm). Can be overridden at runtime with --jamb-software-version.

Type: str | null

Default: null (auto-detected)

trace_from

Starting document prefix for full chain trace matrix. When set, the trace matrix starts from this document and traces down through the hierarchy.

Type: str | null

Default: null (auto-detect root document)

include_ancestors

Include a “Traces To” column showing ancestor UIDs in the trace matrix.

Type: bool

Default: false

tc_id_prefix

Prefix for auto-generated test case IDs. When tests are run with pytest --jamb, each test receives a unique TC ID like TC001, TC002. This option customizes the prefix portion.

Type: str

Default: "TC"

Constraints: Only alphanumeric characters, hyphens (-), and underscores (_) are allowed. Invalid characters will cause a validation error.

Example: tc_id_prefix = "TEST-" produces IDs like TEST-001, TEST-002

!!! note “Changing the prefix” Changing tc_id_prefix only affects newly generated TC IDs. Existing IDs in test files (from @pytest.mark.tc_id) and the .jamb coverage file must be updated manually.

matrix_columns

Extra columns to display in the full chain traceability matrix. Each entry defines a column sourced from an item’s custom attributes. The built-in Review Status column is always present (you do not need to configure it).

Type: list of tables with keys key, header, source, default

Default: []

Each [[tool.jamb.matrix_columns]] entry supports:

Key	Description	Default
key	Custom attribute name to read from the item YAML	(required)
header	Column header displayed in the matrix	same as key
source	"custom_attribute" (read from item YAML) or "built_in" (computed)	"custom_attribute"
default	Value shown when the attribute is missing	"-"

Example Configurations

Minimal (most projects):

[tool.jamb]
test_documents = ["SRS"]

Strict CI enforcement:

[tool.jamb]
test_documents = ["SRS", "SYS"]
fail_uncovered = true
require_all_pass = true
trace_matrix_output = "matrix.html"
trace_to_ignore = ["PRJ"]

Custom TC ID prefix:

[tool.jamb]
test_documents = ["SRS"]
tc_id_prefix = "PROJ-TC-"

Dual-matrix output (trace + test records):

[tool.jamb]
test_documents = ["SRS"]
trace_matrix_output = "docs/traceability.html"
test_matrix_output = "docs/test-records.html"
trace_from = "UN"
include_ancestors = true
trace_to_ignore = ["PRJ", "HAZ"]

Extra columns in the trace matrix:

[tool.jamb]
test_documents = ["SRS"]
trace_from = "UN"

[[tool.jamb.matrix_columns]]
key = "safety_class"
header = "Safety Class"

[[tool.jamb.matrix_columns]]
key = "verification_method"
header = "Verification Method"
default = "test"

With this configuration, items with safety_class: B in their YAML will display “B” in the Safety Class column. Items without the attribute display the default (“-“). The Review Status column is always included automatically.

Document Configuration (.jamb.yml)

Each document directory contains a .jamb.yml file that configures the document:

settings:
  prefix: SRS
  parents:
    - SYS
  digits: 3
  sep: ""

All fields are nested under a settings key.

Fields

prefix

The document identifier used in item UIDs (e.g., SRS → SRS001).

Required

parents

List of parent document prefixes. Defines where items in this document should link to.

Default: [] (root document)

digits

Number of digits in the sequential part of item UIDs.

Default: 3

Range: 1 to 10

Example: digits: 3 → SRS001, digits: 4 → SRS0001

sep

Separator between prefix and number in UIDs.

Default: "" (no separator)

Constraint: Cannot start with an alphanumeric character (would create ambiguous UIDs like SRSX001)

Example: sep: "-" → SRS-001

Creating Documents

Documents are created with jamb doc create, which generates the .jamb.yml file:

jamb doc create SRS reqs/srs --parent SYS --digits 3

See Command Reference for all document management commands.