AI Agent Conversations

Since 11.1.0, SkyWalking stores and serves the conversations of long-lived AI agents. The feature requires the SkyWalking AI Sessionizer as the sender: it is the producer of the files described here, and a record under this layer without their attributes is rejected. The Sessionizer collects an agent runtime’s transcripts into two file formats, Session Data (.sd, the records as collected) and Session Flow (.sf, an append-only chain of rounds that describe the conversation’s structure), and pushes every file as one OTLP log record. The OAP verifies each file on arrival, stores it verbatim, and answers a conversation query with one asz.view document that a viewer renders without opening any file.

In the Sessionizer’s model a conversation is the unit of storage, analysis and export. A session is the source-runtime context a record came from, carried as provenance: one conversation may contain several sessions, and a session belongs to exactly one conversation.

How a file reaches the OAP

The sender puts these resource attributes on every request:

Attribute Value
service.name the name the sender is configured with, or else the runtime that produced the session, such as Claude Code
service.instance.id who is pushing, in words the people reading the OAP recognise: a mailbox, a name or a machine, user@host of the pushing machine by default
service.layer AI_AGENT

Each log record is one file. The body is the file’s text. The record attributes name the file (asz.format, asz.file, asz.file.digest, asz.lines, asz.session, asz.seq for a Session Data file; asz.conversation, asz.round, the conversation’s time range and its title and counts for a round). The two file formats are documented by the Sessionizer under Session Data and Session Flow, and the wire attributes under Export over OpenTelemetry.

The OAP routes these records like every other OTLP log: by layer, to the bundled LAL rule lal/ai-agent.yaml. The rule’s output type, ConversationFile, checks the body’s sha256 against asz.file.digest and its line count against asz.lines, and stores the file in the table its format names. A file that fails either check is dropped and counted in the ai_agent_conversation_files_rejected self-observability metric with the reason as a label, and so is a file larger than maxFileBytes, under the reason size: one file over the storage’s message limit fails the write it travels in, and every record behind it in that write with it, so the limit is applied where one file is one record; a stored file is a verified file. A round’s title and counts are read only when the record carries them: they came with a later round header, and a round from before them lands and lists with zero counts. The service and its instance appear on the service list under the AI_AGENT layer as for any other log sender.

Nothing is folded or decoded at ingest, so an OAP cluster needs no shared state for this feature.

Storage

Two record models, both super datasets:

Model One row per Keys Stored only
ai_agent_session_data Session Data file service_id, service_instance_id, session, indexed seq digest, body
ai_agent_session_flow Session Flow round service_id, service_instance_id, indexed conversation, round session_from_time, title, talks, steps, streams, segments, unresolved, digest, body

A Session Data row carries nothing but its keys and the file: the file’s kind, stream or run, time range and name are on its first line and are read from there. A round’s stored-only columns exist for the list page, which reads them without opening a body; its round number is queryable so a long chain is read window by window. The row’s timestamp is the file’s latest record time, or the conversation’s last activity for a round, so a conversation’s files are found by its own time range. A row belongs to its sender: its id is the service, the instance and the file’s digest, so the same file pushed again by the same sender lands on the same row, and pushed by another service or sender makes another.

  • BanyanDB: both models live in their own group, recordsAIAgent, configured like the log group with hot, warm and cold stages under SW_STORAGE_BANYANDB_AI_AGENT_*, 30 days hot by default. Both tables expire together, because a round whose files are gone is a broken chain. See the BanyanDB storage document.
  • Elasticsearch: two super-dataset index families, sw_ai_agent_session_data-* and sw_ai_agent_session_flow-*, sharded by superDatasetIndexShardsFactor; retention is the single recordDataTTL. The columns the reads sort and range on, seq, round and timestamp, keep doc values.
  • JDBC (MySQL, PostgreSQL, H2): two tables of their own; the body is stored as Base64 text, LONGTEXT on MySQL, since a body near maxFileBytes outgrows MEDIUMTEXT once encoded, MEDIUMTEXT on H2, a CLOB there, and TEXT on PostgreSQL; retention is recordDataTTL.

Query

The list and the export are GraphQL queries in ai-agent-conversation.graphqls; the conversation itself is an HTTP route on the same server, because its document is as large as the conversation.

  • listConversations(condition, duration) lists one row per conversation of a service, optionally of one sender, from the newest round’s attributes. The rounds are read newest first, at most limit (default 1000), then folded to one row per conversation. An optional conversation narrows the read to one conversation by id, and an optional title keeps only the rows whose title contains the text, case-insensitively — matched after folding, on the newest round’s title, so it never widens the rounds read.
  • getConversationRawFiles(condition, files) lists every landed file and round of a conversation with its id, digest and size; selecting body returns the files verbatim, which is the export path. The optional files argument narrows the read to named files.

The conversation view route

GET /ai-agent/conversations/{conversation}/v1/view?service={serviceName}[&instance={instanceName}]

It answers with the whole conversation, once, as one asz.view version 1.0 document, the document the Sessionizer defines under The asz.view document and serves from its own viewer; the OAP’s document equals it, key for key, for the same files. v1 in the path is the document version. The OAP reads the conversation’s rounds over the whole retention window, then the files of each session the head round names over the time range the head round carries, checks the chain, folds the rounds, resolves every reference into the landed records, and renders the document. Verification is content, not an error: a missing round or file, or a failed digest, is written into the document’s summary.state and summary.problems, and the rest of the document holds whatever could still be folded. The fold shows as much as landed: a round that is missing, that does not read, or that the fold refuses is skipped, the chain resumes at the next stored round, and the absent rounds are named once as a range, as are the files a round names that did not land. The round the chain resumes at is listed unverified, because nothing links it to what is absent; the rounds after it verify against it; head names the last round folded. This goes further than the Sessionizer’s own viewer, whose fold stops before the first gap. The document is built on every call and nothing is cached.

Parameter or header Meaning
service / serviceId the service by name, or by id; one of them is required
instance optional, the sender’s instance name from the list row; with it, every storage read is a full series lookup
Accept application/vnd.skywalking.asz.view+yaml, or any type naming yaml, for YAML; anything else, JSON, as asz conversation -json prints it
Content-Type names the document and its version, the HTTP way: application/vnd.skywalking.asz.view+json; version=1.0 or application/vnd.skywalking.asz.view+yaml; version=1.0. The document’s own first two keys, format and version, say the same
Accept-Encoding the body is compressed when the client allows; a document is repetitive text and shrinks several times over
status 200 with the document; 400 when no service is named; 404 when the service stores no round of the conversation; 500 on a storage failure. An error is application/problem+json (RFC 9457): {"type": "about:blank", "title": "Not Found", "status": 404, "detail": "..."}

The route is on the core HTTP server beside /graphql, so it has the same host, port, context path and TLS settings, and serves HTTP/1.1 and HTTP/2 alike. The body is streamed: it is written to the response as it is rendered, never held whole in memory, and a slow client holds back the render. The route runs under its own timeout, viewRequestTimeout, in place of the server’s default of ten seconds, because the floor for a large conversation is seconds of storage reads plus seconds of fold and render.

The conversation page of the UI makes one call, this route, and nothing else.

Configuration

ai-agent-conversation:
  selector: ${SW_AI_AGENT_CONVERSATION:default}
  default:
    fileReadWindow: ${SW_AI_AGENT_CONVERSATION_FILE_READ_WINDOW:16}
    roundReadWindow: ${SW_AI_AGENT_CONVERSATION_ROUND_READ_WINDOW:16}
    maxListLimit: ${SW_AI_AGENT_CONVERSATION_MAX_LIST_LIMIT:10000}
    viewRequestTimeout: ${SW_AI_AGENT_CONVERSATION_VIEW_REQUEST_TIMEOUT:120}
    maxFileBytes: ${SW_AI_AGENT_CONVERSATION_MAX_FILE_BYTES:15728640}
    maxResponseBytes: ${SW_AI_AGENT_CONVERSATION_MAX_RESPONSE_BYTES:104857600}
Key Meaning
fileReadWindow how many Session Data files one storage query fetches, a batch size and not a limit: the view and the raw-file export read every file of the conversation, this many per query. Files are cut at 2 MiB, so a window is a few tens of megabytes; the window times maxFileBytes is the most one query can answer with.
roundReadWindow how many Session Flow rounds one storage query fetches, the same way: the head round is fixed first, then the chain is read from round 1 to the head, this many per query. A round is cut at 2 MiB by the Sessionizer, and the same bound applies.
maxListLimit the most rounds one list query reads before folding, and the ceiling of the query’s limit argument.
viewRequestTimeout how long one conversation view request may take, in seconds.
maxFileBytes the largest file stored, in bytes; a larger one is rejected at ingest and counted under the reason size. 15 MiB by default, under BanyanDB’s 16 MiB gRPC message limit. The Sessionizer cuts files and rounds at 2 MiB; only a round from before that cut is larger.
maxResponseBytes the most bytes one window read may answer with, applied to that read alone on a storage that caps a response per call. The BanyanDB client holds every other read to 50 MB; this module’s two window reads carry it as a call option on the same connection, so nothing else changes. 100 MiB by default, above sixteen files at the 2 MiB cut with room for files landed whole. For a root of larger files, raise it or lower the windows, so that the window times maxFileBytes stays under it; a read over the limit fails as a storage error.

The GraphQL query module requires this module, so it cannot be disabled while the GraphQL query module is active.

Limits on the path

  • The OAP’s OTLP/HTTP endpoint accepts requests of up to 10 MiB, the HTTP server’s default. The Sessionizer’s request budget defaults to 8 MiB for that reason; a single file is cut at 2 MiB, so it always fits.
  • The files of a conversation are read in windows of fileReadWindow files, and its rounds in windows of roundReadWindow rounds, per storage query, inside one view request. On BanyanDB each of those queries may answer with up to maxResponseBytes, 100 MiB by default, as a call option on the shared client in place of its 50 MB default, which every other read keeps; the window times maxFileBytes must stay under it. Elasticsearch answers at most 10,000 hits to one search.
  • A read that is not bound to a duration, the view and the export, covers every retained stage: on BanyanDB the default stages and, when the group keeps one, the cold stage. A conversation the list found in cold storage is served, and one that spans stages is served whole.
  • When the caller names no sender, the view and the export read across every sender of the service and keep one copy of a file or round two senders both pushed, so a Sessionizer renamed between pushes still yields the whole conversation.
  • The asz.view document grows with the conversation. A session of 136 MB of landed files renders to a 70 MB document in about five seconds after about six seconds of storage reads, which is why the view is a streamed route with its own timeout and not a GraphQL query.