bulla 0.15.0

Witness kernel for agent tool compositions — diagnose, attest, seal

bulla

Witness kernel for agent tool compositions — diagnose, attest, seal.

When AI agents compose tools into pipelines, implicit semantic assumptions (date formats, unit scales, encoding schemes) can silently produce wrong results. Type-checking passes, but the pipeline is broken. Bulla computes the coherence fee: the exact number of independent semantic dimensions that bilateral verification cannot detect. For each blind spot, it recommends a bridge and issues a tamper-evident WitnessReceipt.

Zero heavy dependencies. Only requires PyYAML. No numpy, no scipy, no LLM calls. Installs in under a second.

Naming: Bulla is the protocol and tool. SEAM is the underlying theory (paper). Glyph is the company.

Install

pip install bulla

Architecture

Three layers, cleanly separated:

Layer	Concern	Module
Measurement	Composition → Diagnostic (fee, blind spots, bridges)	diagnostic.py
Binding	Diagnostic → WitnessReceipt (content-addressable, tamper-evident)	witness.py
Judgment	Policy → Disposition (proceed / refuse / bridge)	witness.py

The measurement layer has zero imports from the witness layer. Measurement does not know it is being witnessed.

Quick start

bulla diagnose --examples          # run on bundled compositions
bulla scan "python my_server.py"   # scan a live MCP server
bulla check compositions/          # CI gate (exit 1 on failure)

Python API

from bulla import (
    BullaGuard, WitnessBasis, PolicyProfile,
    diagnose, load_composition, witness,
    verify_receipt_consistency, verify_receipt_integrity,
)

# Load and diagnose
comp = load_composition(path="pipeline.yaml")
diag = diagnose(comp)
print(f"Fee: {diag.coherence_fee}, Blind spots: {len(diag.blind_spots)}")

# Witness with provenance
basis = WitnessBasis(declared=3, inferred=1, unknown=0)
policy = PolicyProfile(name="strict", max_unknown=2)
receipt = witness(diag, comp, witness_basis=basis, policy_profile=policy)
print(f"Disposition: {receipt.disposition.value}")

# Verify
ok, violations = verify_receipt_consistency(receipt, comp, diag)
assert verify_receipt_integrity(receipt.to_dict())

BullaGuard (high-level)

guard = BullaGuard.from_mcp_server("python my_server.py")
guard.check(max_blind_spots=0)  # raises BullaCheckError on failure

guard = BullaGuard.from_tools({
    "parser": {"fields": ["amount", "currency"], "conventions": {"amount_unit": "dollars"}},
    "engine": {"fields": ["amount"], "conventions": {"amount_unit": "cents"}},
}, edges=[("parser", "engine")])

MCP Server

Bulla exposes a JSON-RPC 2.0 stdio server with two tools and one resource:

bulla serve   # starts MCP stdio server

• bulla.witness — composition YAML → WitnessReceipt (structured output)
• bulla.bridge — composition YAML → patched YAML + receipt chain
• bulla://taxonomy — convention pack taxonomy

Convention Packs

Layered vocabulary for convention recognition. Later packs override earlier ones.

bulla diagnose --pack financial.yaml pipeline.yaml
bulla scan --pack custom.yaml "python server.py"

Ships with base (10 dimensions) and financial (4 domain-specific dimensions).

Witness Contract

Every receipt binds three hashes: composition (what was proposed), diagnostic (what was measured), receipt (what was witnessed). Receipts chain via parent_receipt_hash for auditable repair flows.

See WITNESS-CONTRACT.md for the normative specification.

CI Integration

# GitHub Actions with SARIF
- run: pip install bulla
- run: bulla check --format sarif compositions/ > bulla.sarif
- uses: github/codeql-action/upload-sarif@v3
  with:
    sarif_file: bulla.sarif

Commands

Command	Purpose
bulla diagnose	Full diagnostic with blind spots, bridges, fee
bulla check	CI gate with configurable thresholds
bulla scan	Scan live MCP servers (zero config)
bulla witness	Diagnose and emit WitnessReceipt as JSON
bulla bridge	Auto-bridge and emit patched YAML + patches
bulla manifest	Generate/validate Bulla Manifest files
bulla serve	MCP stdio server
bulla init	Interactive composition wizard
bulla infer	Infer proto-composition from MCP manifest

Output formats: --format text (default), --format json, --format sarif.

How it works

Bulla builds a coboundary operator from tool dimensions to edge dimensions for both the observable and full sheaves. The coherence fee is:

fee = rank(δ_full) − rank(δ_obs)

Each unit of fee is an independent semantic dimension invisible to pairwise checks. Bridging increases rank(δ_obs) until it matches rank(δ_full). Rank computation uses exact arithmetic (fractions.Fraction) — no floating-point, no numpy.

License

MIT