From 7e20a8db1599fa7f6753c237a29fcc94c6a8b849 Mon Sep 17 00:00:00 2001 From: Aleksandra Spilkowska Date: Tue, 23 Jun 2026 12:36:26 +0200 Subject: [PATCH 1/3] document FastAPI 0.137 regression and fix in 6.26.2 --- docs/reference/supported-technologies.md | 2 +- docs/release-notes/known-issues.md | 11 ++++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/docs/reference/supported-technologies.md b/docs/reference/supported-technologies.md index d60291a0b..2ac53b1bb 100644 --- a/docs/reference/supported-technologies.md +++ b/docs/reference/supported-technologies.md @@ -109,7 +109,7 @@ We support these Starlette versions: * >0.13.0,<1 -Any FastAPI version which uses a supported Starlette version should also be supported. +Any FastAPI version which uses a supported Starlette version should also be supported. FastAPI>=0.137 requires elastic-apm>=6.26.2. ### GRPC [supported-grpc] diff --git a/docs/release-notes/known-issues.md b/docs/release-notes/known-issues.md index 4972fdbc9..0bd085947 100644 --- a/docs/release-notes/known-issues.md +++ b/docs/release-notes/known-issues.md @@ -26,4 +26,13 @@ Known issues are significant defects or limitations that may impact your impleme ::: -_No known issues_ \ No newline at end of file +:::{dropdown} FastAPI 0.137+ causes 500 errors on every request +**Details** +On 06/14/2026, a known issue was discovered that FastAPI 0.137 changed how included routers are represented internally, introducing `_IncludedRouter` wrapper objects that do not expose a `.path` attribute. The ElasticAPM Starlette/FastAPI middleware accessed `.path` unconditionally, causing an `AttributeError` and a 500 response on every HTTP request when using `app.include_router()`. + +**Workaround** +Pin `fastapi<0.137` until you can upgrade to `elastic-apm>=6.26.2`. + +**Resolved** +On 06/22/2026, this issue was resolved in elastic-apm [6.26.2](index.md). +::: \ No newline at end of file From 2f254214f9eb96edfbd6019a9a667cd27e685f15 Mon Sep 17 00:00:00 2001 From: Aleksandra Spilkowska Date: Tue, 23 Jun 2026 14:03:15 +0200 Subject: [PATCH 2/3] apply review feedback --- docs/reference/supported-technologies.md | 6 +++++- docs/release-notes/known-issues.md | 4 ++-- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/docs/reference/supported-technologies.md b/docs/reference/supported-technologies.md index 2ac53b1bb..b31536390 100644 --- a/docs/reference/supported-technologies.md +++ b/docs/reference/supported-technologies.md @@ -109,7 +109,11 @@ We support these Starlette versions: * >0.13.0,<1 -Any FastAPI version which uses a supported Starlette version should also be supported. FastAPI>=0.137 requires elastic-apm>=6.26.2. +Any FastAPI version which uses a supported Starlette version should also be supported. + +::::{note} +`fastapi>=0.137` requires `elastic-apm>=6.26.2`. +:::: ### GRPC [supported-grpc] diff --git a/docs/release-notes/known-issues.md b/docs/release-notes/known-issues.md index 0bd085947..55e83b7fb 100644 --- a/docs/release-notes/known-issues.md +++ b/docs/release-notes/known-issues.md @@ -28,11 +28,11 @@ Known issues are significant defects or limitations that may impact your impleme :::{dropdown} FastAPI 0.137+ causes 500 errors on every request **Details** -On 06/14/2026, a known issue was discovered that FastAPI 0.137 changed how included routers are represented internally, introducing `_IncludedRouter` wrapper objects that do not expose a `.path` attribute. The ElasticAPM Starlette/FastAPI middleware accessed `.path` unconditionally, causing an `AttributeError` and a 500 response on every HTTP request when using `app.include_router()`. +On 06/19/2026, a known issue was discovered that FastAPI 0.137 changed how included routers are represented internally, introducing `_IncludedRouter` wrapper objects that do not expose a `.path` attribute. The ElasticAPM Starlette/FastAPI middleware accessed `.path` unconditionally, causing an `AttributeError` and a 500 response on every HTTP request when using `app.include_router()`. **Workaround** Pin `fastapi<0.137` until you can upgrade to `elastic-apm>=6.26.2`. **Resolved** -On 06/22/2026, this issue was resolved in elastic-apm [6.26.2](index.md). +On 06/22/2026, this issue was resolved in {{product.apm-agent-python}} [6.26.2](index.md#elastic-apm-python-agent-6262-release-notes). ::: \ No newline at end of file From e919442d23cf2220445e99bb7db7d23f2a702b6f Mon Sep 17 00:00:00 2001 From: Aleksandra Spilkowska Date: Tue, 23 Jun 2026 16:39:49 +0200 Subject: [PATCH 3/3] Apply peer review comments --- docs/release-notes/known-issues.md | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/docs/release-notes/known-issues.md b/docs/release-notes/known-issues.md index 55e83b7fb..b94612e7d 100644 --- a/docs/release-notes/known-issues.md +++ b/docs/release-notes/known-issues.md @@ -28,11 +28,14 @@ Known issues are significant defects or limitations that may impact your impleme :::{dropdown} FastAPI 0.137+ causes 500 errors on every request **Details** + On 06/19/2026, a known issue was discovered that FastAPI 0.137 changed how included routers are represented internally, introducing `_IncludedRouter` wrapper objects that do not expose a `.path` attribute. The ElasticAPM Starlette/FastAPI middleware accessed `.path` unconditionally, causing an `AttributeError` and a 500 response on every HTTP request when using `app.include_router()`. **Workaround** + Pin `fastapi<0.137` until you can upgrade to `elastic-apm>=6.26.2`. **Resolved** -On 06/22/2026, this issue was resolved in {{product.apm-agent-python}} [6.26.2](index.md#elastic-apm-python-agent-6262-release-notes). + +On 06/22/2026, this issue was resolved in [{{product.apm-agent-python}} 6.26.2](index.md#elastic-apm-python-agent-6262-release-notes). ::: \ No newline at end of file