notarius/docs/internal/pipeline.md

Pipeline Internals

The implemented resolver and runner live in internal/framework/pipeline. Their fixed workflow and ownership boundaries are defined by Architecture. Configuration fields, defaults, and selectable keys are defined in Configuration.

Pipeline execution is serial. Resolution fixes the selected lanes and all stage bindings before the runner constructs stage implementations.

Resolution

internal/core/config.Config.Resolve validates the loaded configuration, selects the named profile, applies the runtime inputs supplied by the CLI, and calls pipeline.ResolvePipeline.

ResolvePipeline:

1. selects and sorts artifact lanes;
2. completes omitted bindings using the documented configuration defaults;
3. looks up each module and validator spec without constructing it;
4. checks required and provided capabilities in workflow order;
5. resolves target-aware reference bindings and validator chains;
6. calculates a digest over the resolved structure.

Resolution returns a ResolvedPipeline containing ordered lanes, concrete bindings, validator chains, reference targets, and the digest. It does not read reference bytes or construct runtime modules. CLI lane and reference selector syntax is defined in the CLI reference.

Reference Materialization

The CLI calls MaterializeReferences after resolution and before constructing the LLM client or running the pipeline. The materializer checks each binding against its resolved target declaration, reads and validates the file, and builds both a contracts.ReferenceSet and provenance-only metadata on the corresponding ResolvedReferenceTarget.

The runner clones the resulting set into the chunk, extract, merge, or normalize request that owns the target. LLM-backed extensions may convert those items into named prompt inputs. Reference content remains separate from source evidence and source digests.

Binding precedence, path resolution, accepted content, and media-type behavior are configuration contracts; see Configuration. Durable provenance is defined in the JSON output contract, while runtime sensitive-data handling belongs in Operations.

Registries And Specs

pipeline.Registries holds constructors used during execution. pipeline.ModuleCatalog exposes their specs during configuration validation and resolution. Separate registries exist for every stage and for validators; ValidatorChainRegistry stores production default-chain mappings.

A ModuleSpec declares its stage plus required and provided capabilities. Chunk, extract, merge, and normalize specs may also declare reference slots. Registry implementations defensively copy spec metadata, reject duplicate keys, and verify that a constructed implementation reports the registered key.

A ValidatorSpec declares a validator key and execution class. Resolution uses the execution class to reject incompatible profile bindings before execution. The current production catalog and default chain are listed only in Configuration.

Runner Boundary

pipeline.RunInput carries the resolved pipeline, raw source input, structured LLM client, run identity and timing, optional session and profile metadata, and checkpoint/debug collaborators. The runner parses source bytes through the selected input adapter. Later stage requests receive the generic source model; extract requests receive chunk-scoped input material, while chunk, merge, and normalize requests retain access to the original source material.

pipeline.RunOutput carries the run manifest, accepted normalized results, rejected results, warnings, checkpoint events, and logical files returned by the output encoder. The CLI owns diagnostics and durable filesystem writes after the runner returns.

Execution Flow

The runner:

1. validates its input and registries;
2. builds the input adapter, parses the raw input, and validates the generic source document;
3. obtains or executes the chunk result;
4. validates and canonicalizes chunks;
5. executes each resolved artifact lane in order;
6. builds the output encoder and validates its logical file results;
7. returns the assembled manifest, outcomes, warnings, and files.

Within each artifact lane, it builds the extractor, merger, and normalizer, then performs these transitions:

1. extract once per accepted chunk and add runner-owned lane, source, and chunk provenance;
2. validate each raw extract result and omit rejected results from merge input;
3. skip the rest of the lane when no extract result is accepted;
4. merge accepted extract results in their existing order;
5. validate the merge result and skip normalization on rejection;
6. normalize the accepted merge result;
7. validate and append the accepted normalized result.

Module-provided warnings and payload warnings are promoted only from attempts whose results are accepted and used.

Chunk Canonicalization

Before lane execution, generic validation requires unique chunk IDs, matching source identity, indexes matching returned order, valid ordered boundaries, non-empty content and media type, and at least one valid source unit per chunk. Units may not repeat inside a chunk and must preserve source-document order.

The runner then rebuilds each chunk's unit slice from the source document by unit ID. It preserves the module-owned boundaries, content, media type, and cloned metadata. The framework permits gaps and overlap between separate chunks; stricter coverage policy belongs to the chunk implementation.

Validation And Retries

Chunk, extract, merge, and normalize results pass through the resolved validator chain for their stage and module. Each validator receives the raw payload plus the relevant source, chunk, prior-stage, schema, reference, session, LLM, option, and run context. Validators execute in resolved order and stop at the first error or rejection. An empty chain approves the result.

runWithRetry applies the effective retry policy around module execution and its complete validation chain. A module or validator error becomes a framework error when attempts are exhausted. A rejection becomes a recorded RejectedOutput when attempts are exhausted. Cancellation stops retry processing immediately.

Rejected output is a non-fatal pipeline outcome and does not advance. Warnings from discarded attempts are not promoted. Configuration owns retry counts and validator overrides; see Module Bindings.

Checkpoint And Debug Hooks

The runner depends on recorder and loader interfaces, using no-op implementations when collaborators are absent. Each checkpointed workflow boundary records a running, succeeded, or failed transition. Reuse decisions are consulted in workflow order and accepted payloads are cloned before entering the normal handoff path. Dependency fingerprints connect later checkpoints to the exact accepted results on which they depend.

Debug instrumentation wraps run, stage, attempt, validator, and structured LLM boundaries. Context scopes associate nested LLM calls with the module or validator attempt that made them. Debug-write failures are framework errors; debug data is never used as a checkpoint source.

Checkpoint identity, physical layout, reuse behavior, and debug artifact handling are operator contracts in Operations. Serialization and recorder implementation are inventoried in Internal Overview.

Results And Failures

The runner owns manifest assembly and handoff summaries but not the durable JSON schema. It records resolved module and lane provenance, validator chains, source/reference identities, selected LLM profiles, normalized and rejected summaries, status, and timing. Raw payload bytes remain outside the manifest. Module metadata providers may add non-secret singleton or lane-scoped metadata.

Execution errors include stage, module, lane, or validator context. Once a manifest exists, a failing run returns it with failed status and completion time. Successful status reflects whether any raw result was rejected. The durable manifest and logical file schemas are defined in the JSON output contract.

Tests To Inspect

• internal/core/config/effective_config_test.go: config-to-resolution boundary.
• internal/framework/pipeline/profile_test.go: selection, defaults, capabilities, validator chains, and digest behavior.
• internal/framework/pipeline/references_test.go: target resolution and materialization.
• internal/framework/pipeline/runner_test.go: stage transitions, retries, rejections, warnings, checkpoints, debug hooks, and manifests.
• internal/framework/pipeline/walking_skeleton_test.go: fake-backed complete workflow composition.
• internal/framework/checkpoint/*_test.go: checkpoint serialization and reuse collaborators.