Ingest API

You need this page only if you are writing your own client, sending from a language with no SDK, or debugging a transport problem. The Python and TypeScript SDKs implement all of it.

Base URL for the hosted service: https://app.metergraph.dev. For a self-hosted deployment, whatever you set as METERGRAPH_INGEST_URL.

Endpoints at a glance

Method and path	Auth	Scope	Purpose
POST /v1/ingest	mgs_ session token, or mg_ app token	ingest	Send captured call rows
POST /v1/ingest/sessions	mg_ app token	ingest	Exchange an app token for a repository-scoped session token
POST /v1/traces	mg_ app token	ingest	Send OTLP spans, JSON or protobuf
GET /v1/config	mg_ app token	ingest	Read the per-route model configuration document
GET /healthz	none	—	Liveness and database reachability

Authentication

Every authenticated endpoint takes Authorization: Bearer <token>. There are three token formats and they are not interchangeable.

Prefix	Shape	Where it comes from	Lifetime
mg_	mg_ plus 48 hex characters	Minted in the dashboard under Ingest keys, or by the operator CLI	Until revoked
mgs_	mgs_ plus 48 hex characters	POST /v1/ingest/sessions	1 hour
mgl_	mgl_ plus 48 hex characters	Bot delivery leases. Not part of ingestion	Lease-scoped

Only the SHA-256 digest of a token is stored. A token is shown once, at creation, and cannot be recovered.

Scopes

Scope	What it opens	Can the dashboard mint it?
ingest	POST /v1/ingest, POST /v1/ingest/sessions, POST /v1/traces, GET /v1/config	Yes. This is the only scope a dashboard key gets
read	Read APIs	No. Operator CLI only
agent:read	The MCP server	No. Operator CLI only

A dashboard-created key carries exactly ["ingest"]. A token that resolves but lacks the required scope gets 403, not 401.

POST /v1/ingest

The main path. Sends a batch of captured call rows.

Request

POST /v1/ingest HTTP/1.1
Host: app.metergraph.dev
Authorization: Bearer mgs_...
Content-Type: application/json
Content-Encoding: gzip

{
  "schema_version": 1,
  "rows": [ { "ts": "2026-09-10T12:00:00+00:00", "provider": "openai", "model": "gpt-5.5" } ],
  "meta": { "dropped": 0, "transport_errors": 0 }
}

Field	Type	Required	Notes
schema_version	integer	No	Must be exactly 1. A missing value is treated as 1. A boolean or a non-integer is a 400
rows	array of objects	Yes	Non-empty, at most 5,000 entries, every entry an object
meta	object	No	Free-form batch metadata. Must be an object if present. The SDKs send dropped and transport_errors

Row fields are documented in Captured fields. No row field is required. Unknown fields are preserved into the row’s meta column rather than rejected.

Headers

Header	Values	Notes
Authorization	Bearer mgs_... or Bearer mg_...	A mgs_ token is resolved on its own path and its tenant is authoritative. The two formats are mutually exclusive
Content-Type	application/json
Content-Encoding	identity or gzip	Anything else is 415. Absent means identity

Server-reserved row fields

repository_id and protocol_version are stripped from every submitted row before anything durable is written, then re-stamped from the session token’s own resolved identity. A pre-v0.4 app token cannot forge repository attribution by putting those fields in the body.

Response

202 Accepted.

{ "accepted": 100, "ignored": 0, "batch": "<opaque object key>" }

Field	Type	Meaning
accepted	integer	Rows written durably
ignored	integer	len(rows) - accepted
batch	string or null	The batch’s storage key. null when no row survived validation, in which case accepted is 0 and ignored equals the row count

The batch is durable before the 202 returns. Postgres and the queue carry only pointers to it.

Status codes

Code	Condition
202	Accepted, including the zero-accepted case above
400	More than 5,000 rows, an empty or non-list rows, a row that is not an object, a body that is not JSON, a body that is not a JSON object, a non-integer schema_version, a schema_version other than 1, a non-object meta, or a Content-Encoding: gzip body that is not valid gzip
401	Unknown or revoked key, an expired or invalid session token, or an inactive tenant
402	quota_exceeded. The monthly captured-call allowance is spent
403	The token resolves but lacks the ingest scope
413	The body exceeds 8 MiB, checked both before and after gzip decompression
415	A Content-Encoding other than identity or gzip

The 402 body is structured, not a bare string:

{
  "detail": {
    "code": "quota_exceeded",
    "message": "This workspace has reached its monthly captured-call limit.",
    "quota": {
      "period_month": "2026-09-01",
      "calls_counted": 100000,
      "allowance": 100000,
      "over_quota": true,
      "percent_used": 100.0
    }
  }
}

What a client should do with each code

Code	Correct behavior
400, 422	Drop the batch. It will never succeed. Log once
401, 403	With a session token, invalidate it and re-exchange. With an app token, stop sending for the life of the process
402	Stop sending until the next calendar month, or until the allowance is raised
413	Split the batch in half and retry each half, down to a single row. Drop a single row that still fails
415	Fix the header. Do not retry unchanged
5xx and network errors	Exponential backoff. The SDKs start at 1 second and double to a 60 second ceiling

POST /v1/ingest/sessions

Exchanges a long-lived mg_ app token for a short-lived, repository-scoped mgs_ session token. This is how SDK 0.4 and later send rows: the app token touches only this endpoint, never /v1/ingest.

Published schemas: request and response. Both are listed in the contract index with a SHA-256 you can pin.

Request

{ "protocol_version": 2, "repository": "acme/checkout", "sdk_version": "0.6.5" }

Field	Type	Required	Validation
protocol_version	integer	Yes	Must be exactly 2
repository	string	Yes	Non-empty. Matches ^[^/\s]+/[^/\s]+$, so owner/name with no spaces and exactly one slash
sdk_version	string	Yes	Non-empty

additionalProperties is false in the published schema.

Response

200 OK, with Cache-Control: no-store.

{
  "session_token": "mgs_...",
  "expires_at": "2026-09-10T13:00:00+00:00",
  "repository_id": "..."
}

Field	Type	Notes
session_token	string	mgs_ plus 48 hex characters. Returned once, never persisted in plaintext
expires_at	ISO-8601 date-time	One hour from issue
repository_id	string	The server’s stable identifier for repository. Stamped on every row you then send

The repository row is created on first use, so no setup step is needed.

Status codes

Code	Condition
200	Session minted
401	Unknown or revoked app token
403	The token lacks the ingest scope
422	protocol_version is not 2, repository is missing or not a non-empty string, sdk_version is missing or not a non-empty string, or the repository identifier is rejected

Refresh behavior

The SDKs cache the token in memory and re-exchange when it is within 30 seconds of expiry, on the background delivery thread rather than on your request path. A failed exchange backs off from 1 second to a 60 second ceiling, and rows are dropped or buffered in the meantime. The app token is never sent to /v1/ingest as a fallback.

POST /v1/traces

OTLP/HTTP span ingestion, for a codebase already instrumented with OpenTelemetry. This endpoint behaves differently from /v1/ingest in four ways, so read the table below rather than assuming symmetry.

Request

Header	Values
Authorization	Bearer mg_.... Session tokens are not accepted here
Content-Type	application/json or application/x-protobuf. Parameters after ; are ignored
Content-Encoding	identity or gzip

The body is one OTLP ExportTraceServiceRequest, in whichever of the two encodings the Content-Type names.

Response

200 OK, with an OTLP ExportTraceServiceResponse in the same encoding as the request. An empty body means every span was accepted. A partial success looks like this in JSON:

{ "partialSuccess": { "rejectedSpans": "12", "errorMessage": "Metergraph accepts GenAI spans only" } }

rejectedSpans is a string in the JSON encoding, as the OTLP JSON mapping requires. In the protobuf encoding it is partial_success.rejected_spans.

A non-GenAI span is counted, not rejected

Every span that is not a GenAI span is silently counted into rejectedSpans and dropped. On a shared tracer provider that is the normal case and is not an error. A 200 with a large rejectedSpans is what a correctly configured general-purpose OTel pipeline looks like.

Status codes

Code	Condition
200	Accepted, including a partial success and including the case where zero spans were GenAI spans
400	The body is not decodable as OTLP in the declared encoding, or is not a JSON object
401	Unknown or revoked key, or an inactive tenant
402	quota_exceeded
403	The token lacks the ingest scope
413	Body over 8 MiB, before or after decompression, or more than 5,000 GenAI spans. Note that /v1/ingest returns 400 for the row-limit case and this endpoint returns 413
415	A Content-Type other than the two supported, or a Content-Encoding other than identity or gzip

The four differences from /v1/ingest

	/v1/ingest	/v1/traces
Encodings	JSON only	JSON and binary protobuf
Success code	202 with a Metergraph body	200 with an OTLP body
Row limit exceeded	400	413
Unusable input	400	Counted as rejectedSpans inside a 200

Function-level attribution is not available over OTLP, because the span carries no stack. Set route names yourself. See OTLP spans.

GET /v1/config

Returns the per-route model configuration document the SDKs poll for model_for().

Request

Header	Values
Authorization	Bearer mg_.... Requires the ingest scope
If-None-Match	The ETag from a previous response

Response

200 OK, with ETag: "<32 hex characters>" and Cache-Control: max-age=30.

{ "routes": { "checkout.summarize": { "version": 3 } } }

routes maps a route name to its configuration object, with the row’s version merged in. The ETag is a SHA-256 over the sorted document, truncated to 32 hex characters, so an unchanged document always produces the same tag.

304 Not Modified when If-None-Match matches, with the ETag header repeated and no body.

Code	Condition
200	Document returned
304	If-None-Match matched
401	Unknown or revoked key
403	The token lacks the ingest scope

This document is currently always effectively empty

There is no write path that puts a challenger model into routes, so model_for() returns your default. Polling is harmless and the SDKs handle a 401/403 by stopping the poller and logging Metergraph config authentication failed; using default models once.

GET /healthz

Liveness. No authentication, no body.

{ "ok": true }

Code	Condition
200	The server ran select 1 against Postgres successfully
503	The database check raised. Body is {"ok": false}

A 200 from /healthz says nothing about your token

/healthz performs a database round trip and nothing else. It does not read your Authorization header, does not resolve a tenant, and does not check a scope. Earlier troubleshooting advice treated a 200 here as evidence that a token was valid. It is not. To test a token, send a one-row POST /v1/ingest and read the status code. See Errors.

Limits

Limit	Value	Applies to
Rows per request	5,000	/v1/ingest (400), /v1/traces GenAI spans (413)
Body size	8 MiB, checked before and after decompression	Both ingest endpoints
Monthly captured calls	100,000 on a free workspace, unlimited on managed	Both ingest endpoints (402)
Content per field, retained	100 KiB	Written at ingest, not a request-time rejection

See Limits and allowances.

A minimal client

curl -sS -X POST https://app.metergraph.dev/v1/ingest \
  -H "Authorization: Bearer $METERGRAPH_APP_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "schema_version": 1,
    "rows": [{
      "ts": "2026-09-10T12:00:00+00:00",
      "route": "checkout.summarize",
      "provider": "openai",
      "model": "gpt-5.5",
      "input_tokens": 1200,
      "output_tokens": 340,
      "latency_ms": 820,
      "status": "success"
    }]
  }'

For a fuller worked example, including the session exchange and the fields worth sending, see Write your own client.

Related

• Captured fields for every row field
• Errors for every status code with its fix
• Limits and allowances
• Identity model for how tokens, repositories and workspaces relate