# 3GPP Atlas

> A provenance-aware map of 3GPP specifications, releases, working groups, Work Items, Change Requests, procedures and relationships. Atlas is a navigation and research aid; official 3GPP specifications remain the normative source.

## Preferred human-readable entry points
- [Atlas home](https://3gppatlas.sarathchandra.com/): Search-first interface for specifications, procedures, interfaces, Work Items, Change Requests and relationships.
- [Specification directory](https://3gppatlas.sarathchandra.com/specs): Canonical crawlable list of indexed specifications.
- [Per-specification pages](https://3gppatlas.sarathchandra.com/specs/23.501): Replace 23.501 with an indexed specification number.
- [Semantic coverage dashboard](https://3gppatlas.sarathchandra.com/semantic-coverage): Human-readable inventory of reviewed semantic records, release-validity coverage and direct-source coverage.
- [Ask Atlas](https://3gppatlas.sarathchandra.com/ask): Deterministic, release-aware answer synthesis with visible evidence and provenance. Reviewed topic questions use Feature Lineage; semantic expansion candidates remain a separate review-required context.

## Machine-readable interfaces
- [OpenAPI schema](https://3gppatlas.sarathchandra.com/api/openapi.json): Complete API contract.
- [API guide](https://3gppatlas.sarathchandra.com/api/docs): Human-readable guide to the read-only Atlas API.
- [Specifications](https://3gppatlas.sarathchandra.com/api/specs?limit=5000): Full indexed specification identity and status catalogue.
- [Change Requests](https://3gppatlas.sarathchandra.com/api/change-requests?limit=100): Searchable CR catalogue backed by the official bulk CR database and selectively enriched from the 3GPP Portal.
- [CR enrichment coverage](https://3gppatlas.sarathchandra.com/api/change-requests/coverage): Exact canonical, Portal-crosswalk and rich-detail counts. Add `?include_specs=true` for the complete per-specification coverage matrix.
- [Knowledge graph](https://3gppatlas.sarathchandra.com/api/graph): Specification nodes and provenance-aware relationship edges.
- [Semantic catalogue](https://3gppatlas.sarathchandra.com/api/semantic): Reviewed Atlas procedures, topics, interfaces, entities, learning paths and curated fallback relationships with provenance/review metadata.
- [Feature lineage](https://3gppatlas.sarathchandra.com/lineage): Human-readable standards traceability from reviewed topics into mapped specs, Work Items, relationships and CR evidence.
- [Feature lineage API](https://3gppatlas.sarathchandra.com/api/lineage/ntn?release=Rel-17): Release-aware traceability bundle for one reviewed topic.
- [Semantic expansion candidates](https://3gppatlas.sarathchandra.com/api/semantic/candidates/ntn?release=Rel-17): Read-only inferred candidates ranked from structural Work Item, graph and classification evidence; never auto-promoted.
- [Semantic coverage](https://3gppatlas.sarathchandra.com/api/semantic/coverage): Counts by semantic kind and provenance plus referenced-specification coverage.
- [Ask evidence](https://3gppatlas.sarathchandra.com/api/ask/evidence?q=Which%20specifications%20do%20I%20need%20for%20NTN%20mobility%20in%20Rel-17%3F&release=Rel-17): Deterministic evidence bundle used by Ask Atlas; reviewed topic questions include Feature Lineage, while any explicitly requested semantic candidates stay segregated as review-required context.
- [Edges](https://3gppatlas.sarathchandra.com/api/edges): Relationship records with source, edge type, provenance, confidence and review state.
- [Work Items](https://3gppatlas.sarathchandra.com/api/work-items): Work Items with official 3GPP Work Plan progress (release, dates, completion, responsible groups, WID and latest remark) plus connected specifications.
- [Standards change evidence](https://3gppatlas.sarathchandra.com/api/release-changes?from_release=Rel-18&to_release=Rel-19): Aggregate Change Request and Work Item evidence across a release interval; filter by specification, working group, Work Item or mapped topic. This is an evidence index, not a normative clause diff.
- [Observed changes](https://3gppatlas.sarathchandra.com/api/changes): Metadata changes observed by Atlas sync runs.
- [Atlas statistics](https://3gppatlas.sarathchandra.com/api/stats): Corpus and graph counts.
- [Ingestion freshness](https://3gppatlas.sarathchandra.com/api/ingestion/freshness): Official specification/CR/Work Plan fingerprint watcher state, pending refreshes and current ingestion health.
- [Meeting progress](https://3gppatlas.sarathchandra.com/api/meetings/progress): Recent WG/TSG standards activity combining live official meeting-working-area TDocs with canonical CR meeting evidence.
- [Live meeting TDocs](https://3gppatlas.sarathchandra.com/api/meetings/tdocs): Pre-database RAN3/SA2/CT1 TDoc treatment and decision state from official synchronized meeting working areas.
- [Meeting Delta](https://3gppatlas.sarathchandra.com/meetings): Human-readable live and post-meeting standards digest with pre-database and canonical evidence kept separate.
- [Meeting Delta API](https://3gppatlas.sarathchandra.com/api/meetings/delta?meeting_ref=RAN3%23130&level=WG): Combined live TDoc plus canonical CR/spec/Work Item evidence for one indexed WG or TSG meeting.
- [Source integrity](https://3gppatlas.sarathchandra.com/api/source-integrity): Structural audit of all dedicated stored source URL fields; distinguishes structural validity from live reachability.
- [Source reachability samples](https://3gppatlas.sarathchandra.com/api/source-integrity/samples): Bounded deterministic sample of official HTTP(S) source URLs used by the external reachability monitor.

## Change Request provenance
The official 3GPP bulk CR database is the canonical CR corpus. Atlas preserves its canonical identity using `crdb:` source keys. The 3GPP Portal is a selective enrichment source used to attach Portal IDs and richer fields such as reason for change, summary of change, affected clauses and consequence if not approved. Portal enrichment does not replace canonical CRDB identity. Use the CR coverage endpoint to determine current enrichment completeness before assuming rich fields exist for a given specification.

## Provenance model
Atlas labels knowledge as one of four classes:
- official: metadata or relationships directly supported by an official 3GPP source;
- parsed: mechanically extracted from source material;
- curated: deliberately added Atlas classification or relationship;
- inferred: machine- or rule-derived relationship that should be reviewed before relying on it.

When answering standards questions, preserve these distinctions. Do not present curated or inferred Atlas data as normative 3GPP text. Prefer links to canonical Atlas specification pages for navigation and the official 3GPP Portal link on those pages for normative verification.

## Citation guidance
For claims about a specification's title, status, working group, release or version history, cite the canonical Atlas specification page and, when normative accuracy matters, follow its official 3GPP Portal/DynaReport links. For Atlas graph relationships, retain the provenance_type, confidence and review_state fields supplied by the API. For Change Requests, preserve the canonical `source_key`, Portal ID when present, release/revision identity and source URL.

## Full corpus guide
- [llms-full.txt](https://3gppatlas.sarathchandra.com/llms-full.txt): Expanded machine-readable catalogue of currently indexed specifications.